International Conference on BMCT Dubai 2021, April 06-08, BMCTBuilding Materials and ConstructionDubai Technologies 2021 Conference Proceedings
International Conference on Building Materials and Construction Technologies
Conference Proceedings
April 06-08, 2021 Holiday Inn Express Dubai Airport 1 Website: https://bmctdubai.org/ International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Scientific Committee
Fadi HAGE CHEHADE, Professor/Research director, Labanese University, Lebanon
Abhishek Devidas Chaudhari, Research Scholar, Sardar Vallabhbhai National Institute of Technology, India
Saeed Rokooei, Assistant Professor, Mississippi State University, USA
RAMZI TAHA, Professor, Private consultant residing in Texas, USA
Diab A, Associate Professor, Aswan University, Egypt
Hui Mi Hsu, Vice President, National Dong-Hwa University, Taiwan
Mohamed MH Mostafa, Professor, Howard College Campus University of KwaZulu-Natal, South Africa
Qing Wang, Professor, Shandong University of Science and Technology, China
C Sashidhar, Professor, J.N.T.University, Anantapur, India
Alaa Alisawi, Research fellow, Brunel University London, UK
Tom Iseley, Professor, Purdue University, USA
Ahmed MohammedSami Ali Al-Janabi, Researcher, Universiti Putra Malaysia, Iraq
Hosein Naderpour, Associate Professor, Semnan University, Iran
Dipti shukla, Assistant Professor, Manipal Academy of Higher Education, UAE
Arushi Malhotra, Assistant Professor, Manipal Academy of Higher Education, UAE
Linh Truong-Hong, Researcher, Delft University of Technology (TU Delft), Netherlands
Muhtar, lecturer, Muhammadiyah University, Jember, Indonesia
Basim Hassan Shnawa Al-Humeidawi, Assistant Professor, University of Al-Qadisiyah Ad-Diwaniyah, Iraq
Tanmay Gupta, Assistant Professor, Birla Institute of Technology and Science, India
Someyah Nassiri, Assistant Professor, Washington State University, USA
Nazila Roofigari Esfahan, Assistant Professor, Virginia Polytechnic and State University, USA
Elżbieta Macioszek, Professor, Silesian University of Technology, Poland
Ma Zhenjun, Associate Professor, University of Wollongong, Australia
Qing Quan Liang, Associate Professor, Victoria University, Australia
Mohamedel Gafy, Associate Professor, Illinois State University, USA
Faiz Shaikh, Associate Professor, Curtin University, Australia
Ameeta V Kale, Professor, School of Design & Architecture, India
Ghada Diaa, Professor, Housing & Building National Research Center (HBRC), Egypt
Mohamed A El Gawady, Professor, Missouri University of Science and Technology, USA
Nawari O Nawari, Associate Professor, University of Florida, USA
Abdul Qadir Bhatti, Professor, Islamic University Madinah, Saudi Arabia
Hyun-Ki Kim, Professor, Kookmin University, South Korea
2 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Damodar Maity, Professor, Indian Institute of Technology Kharagpur, India
Pramen P Shrestha, Professor, University of Nevada Las Vegas, USA
Ing. Yasser El-Mossallamy, Professor, Ain Shams University, Egypt
Yu-Hang Wang, Professor, Chongqing University, China
Wang Yuanfeng, Professor, Beijing Jiaotong University, China
Gordon Huang, Professor, University of Regina, Canada
Hedayat Omidvar, Head, National Iranian Gas Company, Iran
Khalid, Deputy Head, Leibniz University of Hannover, Germany
Kakuro Amasaka, Professor, Aoyama Gakuin University, Japan
EMMANOUIL SPYROPOULOS, Lead Geotechnical Specialist, SAUDI ARAMCO, Saudi Arabia
Manav Jain, Sr. Cost Engineer, Al Shafar General Contracting LLC, UAE
Andre Furtado, Assistant Professor, University of Porto, Poland
Bharathi Ganesh, Professor and Head, Nitte Meenakshi Institute of Technology, India
ADIL KHAN, Geotechnical Engineer, Soil Improvement Contracting Company, Saudi Arabia
Eunsoo Choi, Professor, Hongik University, Korea
N Ranganath, Chairman & Managing Director, E I Technologies Pvt. Ltd., India
Husam Rabah Alsanat, Assistant Professor, AHU University, Jordan
Federico Rossi, Professor, University of Perugia, Italy
3 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Contents
Suitability of Chrome Slag as an Aggregate for Asphalt in South Africa ...... 5
Deep Dynamic Compaction and Rapid Impact Compaction adopted to Treat Loose Soil Formations and Fill Compaction for Large Structures and Roads - Case Study ...... 14
Stone Columns as a Remedial Solution to a Compromised Roller Compaction Activity for a Substantial Thickness - Case Study ...... 24
Web Crippling Investigations of Aluminium Lipped Channel Sections with Web Opening – Two-Flange Loading Conditions ...... 33
Mathematical prediction of the structural substance of asphalt pavements as a prerequisite for economical maintenance ...... 39
Risk in Solar Parks: A Parametric Approach of Comparing AHP and TOPSIS Methods ...... 46
Structural Behaviour of Reinforced Self Compacting Concrete Incorporating Alccofine and Fly ash ...... 63
Buckling bearing capacity of curved steel-concrete-steel sandwich composite shell under axial compression ...... 70
Planning and Mapping of a Multi modal Integrated Transportation System for Metro station at Dadar, Mumbai India by Using Open Source GIS
...... 76
4 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Suitability of Chrome Slag as an Aggregate for Asphalt in South Africa
M.W. Heyns1, Mohamed M H Mostafa2* and E. Mukandila3
1Civil Technologist, Pr Tech Eng., Jodan Construction, South Africa 2Sustainable Transportation research group (STRg), Civil Engineering, School of Engineering, University of Kwa-ulu Natal, https://orcid. org/0000-0002-5163-5861; South Africa
3Civil Engineer. Pr Eng., Technical Director: Roads Division, IX Engineers, South Africa
*Corresponding author: Mohamed M H Mostafa, Sustainable Transportation research group (STRg), Civil Engineering, School of Engineering, University of Kwa-ulu Natal, South Africa, Email:
Abstract Large quantities of natural materials are traditionally used in road construction which leads to depletion of non-renewable natural resources. Concurrently the world faces the problem of management of an increasing quantity of waste so that linking the two issues leads to a simple solution: growing and more diverse application of waste materials in roads and other areas of civil engineering similarly.
Approximately 20 million tons have accumulated on Chrome Slag dumps in South Africa, and a further 0.5 million tons are added every year. The total amount of one area (Witbank area) alone is 450 000 tons and increases every month. Complete elimination of the production of Slag is impossible at this stage.
important. Therefore, a large study is established to design asphalt mixes incorporating Chrome Slag. Consequently, the suitability of this material to be used as aggregates in asphalt mixes can be signi�icantly This preliminary study investigated the suitability of Chrome Slag as a replacement of natural Dolorite for asphalt mixtures as the Slag conforms to the requirements as set out in design procedures developed for South African conditions. The material was tested for physical properties, hardness, toughness, and durability. Chrome Slag showed generally favourable results when compared with the Dolerite samples. It, however, showed softer toughness values than that of the Dolerite. The Slag showed that it conforms to enough requirements, and the test revealed and can be a viable option as asphalt aggregate. The results encouraged continuation with the large project to arrive at proper mixes incorporating Chrome Slag.
Keywords: Natural Aggregate; Chrome Slag; Durability; Non-conventional materials; Asphalt
Introduction
Pavement design is grounded on attaining structural quality for Aggregate is one of the main components of an asphalt mix each layer of material (Guyer, 2011). Each layer in the design must design as it constitutes the more substantial portion of material used in the manufacture of hot mix asphalt. The physical properties cracking within the layer or in the overlying layers and prevent of aggregate are generally regarded as the most critical aspect be resistant to shearing, excessive de�lections that will cause fatigue of aggregate selection. The physical properties of aggregates are inclusive performance of an asphalt mix depends on, amongst affected by several factors including, but not limited to, mineralogy permanent deformation through densi�ication (Guyer, 2011). The of the parent rock; the extent to which the parent rock has been if used. altered by leaching, oxidation etc.; as well as by the processes others, the properties of the aggregate, binder, �iller, and additives required to produce graded and blended aggregates. The majority of
5 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings aggregate sources are rarely totally uniform in quality. The existence record in road building with Slag was in 1830. Some years after constructed with Slag were built in England in 1813. The �irst actual of the aggregate (SAPEM, 2011). Hard and rough textured aggregate the use of Slag in road construction, with very good experiences, resultsof distinct in stablegeological and formationsrut-resistant can hot signi�icantly mix asphalt affect mixes the (Komba quality the railway started using Slag in the construction of lines as well (Barisic,2010). aggregateJ, 2014). Durabilityshould be able is another to resist signi�icant breaking down feature and that disintegration should be underin�luenced environmental by aggregates conditions. used in the manufacture of Asphalt. The 1969. The results obtained showed very good properties in terms The �irst experience of Slag in asphalt mixtures is dated as of bearing capacity, resistance to external impacts, and durability (Emery, 1982). Slaghas become known as secondary aggregates aggregates in terms of shape. Flat and elongated aggregate particles Equal dimensional aggregate is preferred over �lat and elongated which have similar physical properties to the conventional, primary during the compaction process (Button, et al., 1990; Arasan, et al., aggregate and can be processed, crushed and screened into practical 2011).tend to Angular lock up aggregate and resist particles orientation are favoured which resultsover round-shaped in dif�iculty size for easy batching into both surfacing and base asphalt surfacing aggregates as they improve aggregate interlock providing improved resistance to rutting and improve the resilient response of asphalt most natural aggregates is its high particle density, which is the (Mikoc, 2010). The most signi�icant difference between Slag and mixes (Pan et al., 2005). consequence of the presence of iron compounds.
Dolerite is one of the naturally abundant road building materials for the construction of high-quality pavement road layers in quantity of calcium oxide, CaO. The amount of CaO indicates the Slag is also known as a pozzolanic material as it has a signi�icant South Africa. It is associated with the primary crystalline group of existence of the possibility of utilising Slag as a binder (Barisic, rocks. Dolerite is a common type of felsic intrusive igneous rock 2010). The partialreplacement was alsopossible. that primarily contains feldspar, quartz, hornblende andmica. As aggregate needs to be durable and, testing requirements have South Africa has an excess of Slag that covers hectares of ground. been established to ensure the durability of the required materials, Some plants have been recording slag dumps in excess of 5 million tons, which occupy approximately 5 ha. Plants are planning to amount of desirable durability properties that are required for road increase steel production, thus increasing slag dumps. An example pavementreactivity construction and near lack of cleavage give Dolerite a signi�icant of a plant is found in Machadodorp, which has a planned increase in Slag to over 8.5 million tons by the year 2025. On the other hand, Slag falls in a category of aggregate named “manufactured aggregate” due to being a by-product of an industrial Paige-green et al.; 2013, noted that aggregate plays a vital process. The manufactured aggregate can also be crushed and serve role in determining the overall performance of asphalt mixes in the purpose in a civil engineering environment. The Slag is straight granulated during drumming where ferrochrome is tapped into the performance of a Hot Mix Asphalt (HMA). Niemela et al.; 2007, pavements. Slag conforms to all the properties that are signi�icant to the granulation pond, where high-pressure water breaks Slag into further stated that Slag is hard and stable and is well suited for scoops. The excess from the scoops �lows along the slag launder to demanding structures. The study concluded that the slag products dumped on-site (Niemela, 2007; Hattingh, 2003). small fractions and ef�iciently it cools down, and the �inal Slag is then layers and also as aggregate in Asphalt. The use of slag products This study will investigate some aspects of aggregate testing could be used for road construction in the �iltering and supporting will also speed up the construction and thus make the slag products a naturally occurring aggregate (Dolerite). more economical (Niemela et al.,2007). speci�ications by comparing the use of a waste by-product (Slag) to Natural aggregate sources are depleting due to high demand and Literature Review the amount of disposed waste material keeps increasing. Therefore, Slag is a waste material produced in cathartic metals, their researchers are exploring the use of alternative materials to reserve casting and alloying. In South Africa, the submerged electrode arc- natural aggregates and save the environment. The utilization of smelting process is mainly used. During this process, the chromite the properties of pavement. This will shift the gear in sustainable Slag will reduce land�ill, preserve natural resources and improve (coke, char and coal) to produce the feedstock. The feedstock is fed pavement construction, which is most desirable in today’s energy- ore is blended with carbon-rich material (reductants) and �luxes into an electric-arc furnace where it is melted (Papp, 2000). de�icientThis preliminaryworld (Hainin, study, 2012). which conforms part of a larger study, The use of Slag has been recorded as early as 700 B.C. (Barisic, investigated the suitability of Chrome Slag as a replacement of natural Dolorite for asphalt mixtures as the Slag conforms to the as the Roman era, when slag rubble from the processing of crude 2010). Slag was used for the �irst time in road construction as early requirements as set out in design procedures developed for South African conditions. iron was utilised in building the roadbeds. The �irst modern roads 6 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings Materials and Methodology
The materials supplied for the study is natural crushed Dolerite and chrome slag. The aggregate testing is completed as per the following:
1. Interim Guidelines for the Design of Hot-mix Asphalt in South Africa, 2001 (IGDHMSA,2001). 2.
ResultsCommittee validation of are Land undertaken Transport using Of�icials, Interim 1998 Guidelines (COLTO,1998). for the Design of Hot-Mix Asphalt in South Africa, table 3.1. The tests were completed on both natural (Dolerite)Table and1: Tests slag aggregates, used to evaluate and these the speci�ications Physical Properties are summarised of Aggregates in table 1.
Property Test Designation Criteria
Fines Aggregate Crushing Test
Minimum:
(10% FACT) SANS 3001 – (-10,0mm + 7,1mm fraction) & AG10&AG15 (-7,1mm +5mm Fraction) 160kN Hardness/Toughness Aggregate Crushing Value
SANS 3001 – Max: 25% AG10 (ACV)
tors: No standards Speci�ied. Indica- Methylene Blue Adsorption SANS1243 >5:<5: AdditionalHigh quality Testing �iller Required Durability/Soundness
Ethylene Glycol SANS 3001 – Visual evaluation AG14 Max: 9,5mm Aggregate - 30
Flakiness Index Test SANS 3001 – 6,7mm Aggregate - 30 AG4 Particle Shape and Texture Polished Stone Value (PSV) SANS 3001 – Min: 50 AG11 SANS 3001 – AG20& Absorption Max: 1% by mass
Water Absorption AG21 Cleanliness Sand Equivalent Test SANS 3001 – Min: 50 on Total Fines Fraction AG5
ACV and 10% Fines Aggregate Crushing Values (FACT)
The straight dry and wet aggregate crushing test is normally carried out using either ACV or 10% FACT. The test assesses the strength properties of the aggregate. The difference between ACV and 10% FACT is that ACV determines the percentage �ines produced under a load an indication of weaker materials; therefore, the 10% FACT is the preferred method. For the durability of aggregates, the wet 10% FACT of 40kN/min up to 400kN over 10 minutes while the 10% FACT determines the load required to produce 10% �ines. ACV is less reliable for is carried out as part of the normal 10% FACT test. Aggregates are prepared as for the standard test requirements but are soaked in water
7 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings for 24 hrs. The test is carried out for both dry and soaked aggregate, and the results are reported in percentage. A wet/dry ratio of greater than 75% indicates satisfactory durability. Table 2 shows the results of the comparison materials. In addition to the testing, aggregate soaked in Ethylene Glycol for 4 days must also be subjected to the ACV and 10% FACT test procedures. The results of the Ethylene Glycol test
SANS3001– AG15; SAPEM, 2014; COLTO, 1998; IGDHSA, 2001). procedures must conform to the requirements as speci�ied in the documents to ensure durability. (SANS3001– AG10; SANS3001– AG14; Table 2: Hardness results of the aggregates Material Description
Description Test Method UOM Slag Aggregate 9,5mm 6,7mm 9,5mm 6,7mm ACV Dry SANS 3001 - % 12,5 12,7 5,5 6,1 AG10 ACV Wet SANS 3001 - % 13,9 13,4 7,9 8,1 AG10 ACV Wet (E.G.)1 SANS 3001 - % 14,2 14,7 8,2 7,9 AG10 10 % FACT Wet/Dry Ratio SANS 3001 - AG9 % 91 95 66 68
10 % FACT Wet/Dry Ratio SANS 3001 - AG9 % 93 93 61 69 (E.G.) 10% FACT Dry SANS 3001 - AG9 kN 305 294 799 737
10% FACT wet SANS 3001 - AG9 kN 277 279 527 504
10% FACT Wet (E.G.) SANS 3001 - AG9 kN 282 272 488 506
Durability/Soundness 1. Shed of small fragments fromedges Fractured into not more than 3pieces Durability and Soundness is the ability of the aggregate to resist 2. breakdown and disintegration under the action of theenvironment. 3. Disintegrated, samples split into more than 3pieces The tests included in this section are namely; Ethylene Glycol The results of the test will indicate possible problematic Durability Index and the Methylene Blue test. aggregates that will affect long term durability. As the effect of the ethylene glycol depends on the accessibility of the liquid to Ethylene Glycol Durability Index (EGDI) the deleterious clays within the aggregate pieces, the test was Ethylene Glycol is used to check the durability of the Acid/ Basic durabilityproblem. Paige-Green reported that the EGDI after 20 Crystalline rock groups and now Slag.The test is a good indicator carried out for 20 days to �ind out if there could be a longer-term of the potential breakdown of the aggregates in medium to long days will be greater than 1.5 times the EGDI after 5 days. Moreover, term after exposure to the atmosphere. Rapid weathering does the materials durability will be a suspect. The results of the EGDI occur when rocks contain smectite clay minerals and Dolerites, following criteria should apply: which are known for the primary minerals in the rock to be altered 1. to active clay smectite (Jenkins, 2011; Paige-Green, 2007; SANS DurabilityIndex) 3001 – AG14). The test includes soaking rock fragments in ethylene Subbase – EGDI< 20 (modi�ied Ethylene Glycol glycol while observing deterioration on a daily basis. The durability 2. Base Course – EGDI<10 3. EGDI after 20 days < 1,5 x EGDI after 5days index is obtained by adding the disintegration classi�ication (which (which indicates the number of days taken for the most severe indicates the severity of the disintegration) to the time classi�ication The results are combined in Table3. The reason is that all the disintegration to take place). A modi�ied technique, suggested by showed no physical change when the subdued to the Ethylene Glycol This technique is to assess each aggregate and its behavior with aggregates observed during the required time of speci�ied testing Paige- Green, uses 40 pieces of aggregate placed in a �ixed position. solution. Figures 1 and 2 shows the condition of the aggregate Slag the time recorded. The inspection should take place after 5, 10 and and the natural Dolerite soaked in ethylene glycol after 20days. 20 days. The individual pieces are recorded with the following 3 assessments:
8 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Figure 1: Slag soaked in Ethylene Glycol
Figure 2: Dolerite Aggregate soaked in Ethylene Glycol
Table 3: Concluded EGDI results for both Slag and natural aggregate
Day Spall- Ds Frac- Df Disintegrated C Dd Dura- ed a tured ᵇ bility Index 1 0 0 0 0 0 0 0 5 0 0 0 0 0 0 0 10 0 0 0 0 0 0 0 20 0 0 0 0 0 0 0 a Weighting 0,5 Factor b Weighting 1 Factor c Weighting 2,5 Factor Type of deterioration De�inition Spalled (Ds) Shedding of small fragments from aggregate edges fractured (Df) Splitting into two or three pieces Disintegrated (Dd) Splitting into more than three pieces
5-dayEGDI 20-dayEGDI 1,5 x 5-dayEGDI 0 0 0
9 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Note: Both slag and aggregate results have produced exact width for the appropriate size fraction. This is expressed as a same results; therefore, the above table was inserted to show what percentage of the total mass of that aggregate. The width of the slots the results were for both materials in the study. 0=No change in is half that of the sieve openings through which each of the fractions aggregates observed during the required time frame of thetest. passes (SAPEM, 2014; COLTO, 1998; IGDHSA, 2001; SANS 3001 – AG4, 2012).
Methylene Blue Test The test is carried out by determining the percentage of the total
Methylene Blue Test is a rapid qualitative test for determining in a metal plate. The standards specify that the test should be carried mass of the aggregate that passes through slots of a speci�ied width deleterious swelling clay minerals which could adversely affect whether the clay content of the �ines of an aggregate contains the quality of the asphalt mixture (SAPEM, 2011). The deleterious out on two fractions of the aggregate. COLTO speci�ies maximum swelling clay materials usually results in the weathering of rock. for �lakiness index for aggregates (COLTO, 1998). The results of the describe the shape of the aggregate. Experience shows that the methylene blue values of 5 or less are testing are shown in Table 5. The �lakiness index is a rough guide to Table 5: Flakiness results according Fillers with methylene blue values above 5 should further be indicative of high-quality �iller that can be used in asphalt mixtures. evaluated by means of hydrometer analysis and Atterberg analysis Nominal sizeto speci�ication (COLTO, 1998) Natural (IGDHSA, 2001). of the aggre- Aggregate gate Slag (Dolerite) The test is completed by weighing out by and dispersing 1g of ness index Maximum �laki- a sample of material passing 0.075 mm sieve in water. The sample 9,5mm 30 13,4 14.1 is then titrated with an indicator dissolved solution of methylene 6,7mm 30 12,5 12,6 blue. Quantity of the solution is added in increments of 0.5ml until Polish Stone Value (PSV) achieve the effect (SANS 1243, 2012) as shown in Table4. a �ine halo appears. The amount of the solution is then calculated to The PSV indicates a measure of the resistance of pavement Table 4: Methylene Blue test results stones to the polishing action of the vehicle tires under conditions Reference Test Meth- Requirement Result similar to those occurring on the surface of a road (SANS 5848, sample od 2008).
SANS 1243 The PSV test is applicable to aggregates as it plays a major role in >5: Additonal Testing macro surface texture. The aggregates are subjected to accelerated Dolerite <5: High quality �iller 0,1 Required polishing machine using emery abrasive powders and water. The SANS 1243 >5: Additonal Testing Slag <5: High quality �iller 0,15 PSV values relate to general conditions of traf�ic �low. For high and Required heavy traf�ic values, it is recommended that the PSV values are at a value of 47 can be adopted. According to the SAPEM manual and minimum value of 55 whereas, for low traf�ic volumes, the minimum Particle Shape and Texture (SAPEM, 2014; COLTO, 1998; IGDHSA, 2001; SANS3001– AG11, The workability and stability of an asphalt mixture are affected COLTO, the required minimum speci�ication should be at least 50 2012). The test is in two parts, namely; by the shape of the aggregate particles. Angular aggregates promote stability while rounder aggregates tolerate the work ability. It 1. Samples of stone subjected to a polishing action in a is recommended that during the design and evaluation of the polishingmachine aggregates, 95% of the aggregates have at least 3 fractured faces. Flat, elongated and thin aggregates should be avoided as these types 2. State of polish reached is measured by means of a friction of shapes will cause problems during paving and compaction of the test and is expressed as the laboratory determined PSV. asphalt layer (SAPEM, 2014; IDGHSA, 2001). The tests discussed and evaluated are namely; Flakiness Index and Polish Stone Value. Table 6: Polish Stone Value results
Ref Test Method Requirement Result Flakiness Index Dolerite SABS 848 Min: 50 53 Slag SABS 848 Min: 50 52 The �lakiness index of a coarse aggregate is known as the mass of particles in that aggregate which will pass the slots of speci�ied 10 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings Absorption The test assesses the quality of the aggregates. Aggregate with high water absorption indicates poor qualities. Two tests are completed sieve fractions. The water absorption test samples are soaked in water for 24hrs before being brought to a saturated surface dry condition to �inalise the concluded results. The tests are completed with aggregates retained on the 5mm sieve and then on material passing the 5mm between saturated surface dry of the oven-dried aggregates. Table 7 shows the result comparison between the Slag and the Doleritesamples. and the weighed. The samples are then oven-dried and weighed. The results are expressed as a percentage de�ined as the loss of mass Table 7: Water absorption results
Dolerite Slag Test Method Requirement 9,5mm 6,7mm 4,7mm 0-2,75mm 9,5mm 6,7mm 4,7mm 0-2,75mm SANS3001– Max:1%bymass 0,6 0,4 0,7 0,4 0,8 0,7 0,9 0,4
AG20&AG21
Sand Equivalent Results and Discussion
Sand equivalent test indicates the relative proportion of clay-like It must be considered that for an effective asphalt layer, materials to sand particles in the granular material. The higher the aggregates must display more rough angular material than smooth sand equivalent value is, indicates that there is less clay-like material material. The properties of the aggregates must conform to the in the samples. Clay-like materials have a through effect on the following set standards: performance of asphalt mixes, and the amount should be controlled. 1. Hardness/ toughness A large number of clay-like particles can coat the aggregate surfaces and prevent the binder from completely coating and adhering to the 2. Durability aggregate. 3. Shape and surfacetexture
4. Absorption and cleanliness The sample is then oven dried and transferred into a transparent The test consists of �ine aggregate passing the 5mm sieve. The Slag conformed well when compared to the natural measuring cylinder. A solution of calcium chloride, glycerine aggregate. Ethylene Glycol test was included in the hardness/ and formaldehyde diluted in water is added to the sample. The toughness test, as the results must also conform to the set standard. transparent cylinder is thoroughly shaken after which a metal Both Slag and the natural aggregate have performed well above the requirements of the hardness/toughness tests. However, the 6.7mm stand undisturbed. A weighted foot is inserted into the cylinder after irrigator is used to �lush �ines upwards. The cylinder is then left to slag fraction has shown that it is “softer” than the natural aggregate onto the sand readings. The sand equivalent is then calculated by 20 minutes at the top of the �ines reading; it is then further lowered but Bothstill is the within natural the aggregaterequired speci�ications. and Slag conformed to the durability values of EGDI and Methylene Blue tests. All samples showed a zero expressing the �ines reading as a percentage of the sand reading. compared to those with low sand equivalent values (SAPEM, 2014; effect when soaked in the EGDI and that, there are no substantial High sand equivalent values specify improved quality �ine aggregate SANS 3001 – AG5). Table 8 shows the sand equivalent results of both deleterious clays found with results of 0.1 for the natural aggregate the Slag and the Dolerite samples. and 0.15 for the Slag which would affect the asphalt mixture. Both the materials in this study showed high durability for a required life Table 8: Sand Equivalent results spandesign.
Reference Shape and surface texture of the aggregates play an important sample role for work ability and compatibility of the asphalt mixture; Test Method Requirement Result
SANS 3001 Min: 50 on Total are adhered to in the design process. The polish stone values are Fines therefore, it is critical that polish stone values and �lakiness index Dolerite - AG6 86,4 very close for both the materials in this study; values of 53 for the Fraction natural aggregate and 52 for the Slag respectively. No problems are SANS 3001 Min: 50 on Total foreseen in the workability and compatibility of the materials as Fines Fraction Slag - AG7 79,2 other, thus showing that the Slag will have the same durability values each has very low �lakiness index results. Both are very close to each
11 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings required by the standards. The surface texture of these aggregates in Acknowledgement this study affects the skid resistance of the layer. Both provide harsh textures, thus increase the skid resistance at low speeds. The authors are indebted to AFRIGRIT for the supply of the Slag samples, AFRISAM for the Dolerite samples and to Roadlab Water absorption is another critical property, as this will Civil Engineering Materials Laboratory for the undertaking of the indicate whether the aggregate is prone to exponential absorption experimental work. that will affect the binding of the binder to the aggregate. It is thus critical that all results must be below 1% by mass. Calculating the average results obtained per grading, as shown in table 6, the results are 0.5 for the natural aggregate and 0.7 for the Slag. It has been References known that Slag will absorb more binder that aggregates as they do Arasan S, Yenera E, Hattatoglu F, Hinislioglue S and Akbuluta S. contain more pores, but this will not affect the mixture as a result Correlation between shape of aggregate and mechanical are still below the required standard. properties of asphalt concrete. Road pavement material design. 2011;12(2):239-262. The sand equivalent results show that very little clay-like materials are found with values of 79.2 for the Slag and 86.4 for Barisic I, Dimter S, Netinger I. Possibilties of Application of Slag in Road Construction. Technical Gazette. 2010;17(4):523-528. mixture will have an affective bond, thus increasing the stability/ the aggregate. This does show that the binder used for the speci�ic durability of the mixture. in asphalt concrete pavements. Transportation Research Button JW, Perdomo D, Lytton RL. In�luence of aggregate on rutting Conclusion Record 1259. Transportation Research Board, National Research Council, Washington DC. 1990:141-152. The materials in this study are used to replace conventional materials that must be mined and processed; using by-product materials preserves natural resources and reduces the energy use and pollution associated with these activities. Using by-products EmryCommittee JJ. Slag ofUtilization Land Transport in Pavement Of�icials Construction.(COLTO), 1998 Extending Edition. could and probably will make the roads more durable. Therefore, Aggregate Resources. ASTM Special Testing Publication 774, maintenance is envisaged to be less frequent, which is good for the American Society for Testing and Materials, Washington, DC. environment because to conserves natural resources andenergy. 1982:95-118.
Guyer PE. Introduction to Soil Stabilisation in Pavements. Course It is shown in this study, that industrial materials offer signi�icant No. 1982: C03-028. layer is envisaged to have a high-friction surface that makes driving performance enhancement bene�its. Chrome slag in the asphalt safer. The used Slag has comparable physical properties to the Hattingh J, Friend JF. Envronmental and economic implications conventional aggregate and can be produced into desired practical of slag disposal practices by the ferrochromium industry/; A sizes for easy batching into both surfacing and base asphalt layers. case study. ISSN 0378-4738 = Water S.A. 2003;29(1):23-30. The utmost noteworthy difference between steel slag and most conventional aggregates is its high particle density, as a result of iron Interim Guidelines for the Design of Hot-Mix Asphalt in South compounds. Africa, September 2001.
This study has shown that the use of Slag as are placement of Komba JJ, OConnel J, PaigeGreen P.Evaluation of the Performance natural aggregate can be utilized in an asphalt mixture as the Slag of Aggregate in Hot-Mix Asphalt.Proceedings of the 33rd conforms to the requirements as set out in design procedures Southern African Transport Conference (SATC 2014). developed for South African conditions. The study further showed Proceedings ISBN Number. 2014:978-1-920017-61-3. that slag products are suitable materials for road construction and that the use of slag products will speed up the construction, as they are readily available and thus making the slag products more the mechanical and physical properties of asphalt. Technical Mikoc M, Markovic. In�luence of slag, �ly ash and silica fume on economical. The results can, therefore, be concluded that although Gazette. 2010:17(4);505-514. the Slag does show softer toughness values than that of the Dolerite, Niemela P, Kauppi M.Production, Characteristics and Use of it can still be used as a replacement for the natural aggregate with Ferrochromium Slags. Innovation in Ferro Alloy Industry. high conclusive foreseen performance. It is recommended, however, INFACON XI. 2007. that all slagmaterials be thoroughly tested to ensure all physical properties are met for a speci�icproject. 12 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Paige Green P, A revised ethylene glycol test for assessing the durability of basic crystalline materials for road aggregate. MRC-08, Geological construction materials – Part 1. 2013.
Pan T, Tutumluer E, Carpenter H. Effect of coarse aggregate morphology on the resilient modulus of hot mix asphalt, TRB 84th Annual Conference, Washington DC, USA.2005;1929(1):1-9.
South African Pavement Engineering Manual, 2011, Chapter 3,.Material Testing. Revision 1.(SAPEM, 2011).
13 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Deep Dynamic Compaction and Rapid Impact Compaction Adopted to Treat Loose Soil Formations and Fill Compaction for Large Structures and Roads - Case Study Khan A1, Ahmad J1, Alshokur H1, Spyropoulos E2*
1Soil Improvement Contracting Co., Dammam 32232, Kingdom of Saudi Arabia. 2Saudi Aramco, Dhahran 31311, Kingdom of Saudi Arabia.
*Corresponding author: Spyropoulos E, Saudi Aramco, Dhahran 31311, Kingdom of Saudi Arabia. Email : [email protected]
Abstract The current case study is concerning a facility located near Dammam, Saudi Arabia. The project consisted of three main categories of design criteria to be achieved. It included nine Bearing Capacity
for Road/Open Areas and Liquefaction Risk Mitigation criterion for the entire site, which encompassed and Settlement criteria for in�inite, combined and isolated foundations, Relative Density (Rd) criterion an area of approximately 180,000m2. The allotted time for soil improvement works was limited to
granular material and the depth of improvement went as deep as 10m. Both Dynamic Compaction 6 months, due to the project being of fast-track category. The soil pro�ile was composed largely of and Rapid Impact Compaction are popular techniques in compacting granular material, due to their
cost-effective and clean, in terms not requiring water nor electricity for operations compared to Vibro- high ef�iciency in achieving the design criteria and fast rate of improvement. The techniques are also Improvement counter techniques, proving to be value-engineered options. The improvement area
wherein the techniques would be implemented independently or in combination with one another. was segregated into three regions based on existing loose soils and �ill compaction requirements, The production works lasted around 4.5 months. Post-Improvement Quality Control tests indicated the
Compaction and Rapid Impact Compaction techniques in terms of achieving the design criteria and a achievement of Design Criteria by a substantial margin, exemplifying the ef�iciency of Deep Dynamic fast rate of production in operations.
Introduction Table 1: List of Abbreviations
The project location is situated in the northeast of Dammam, Abbreviation Description KSA. The project consisted of structures, parking areas and roads, for a total area of 180,000m2. The scope of work included existing KSA Kingdom of Saudi Arabia DC Dynamic Compaction projectsoil improvement was fast track and �illand compaction required optimized works. The improvement soil composition and DR Dynamic Replacement compactionwas mainly granularstrategy withto meet presence a 6-month of stiff deadline. �ine-grained With layers. the same The VC Vibro Compaction and an expensive option. The same constraint motivated the need VR Vibro Replacement forconstrained value-engineered requirement, alternatives. roller compaction would prove dif�icult CPTu Piezocone Penetration Test The current paper consists of the following abbreviations as
Rd Relative Density de�ined in Table 1. qc Cone Tip Resistance
Ic Soil Behavior Type Index
14 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings Background Problem Statement
Two soil investigation campaigns were conducted prior to Taking into account the soil conditions, earthwork requirements improvement-compaction works. The campaigns will hereafter and constrained schedule, optimized strategy for soil improvement be referred to as SI(A) and SI(B). Both investigations were carried out mostly at the structures locations. As per investigation works replacement, followed by conventional layer-by-layer roller and �ill compaction requirement was identi�ied. Removal and be used as a summary of geological conditions. compaction would prove expensive and prevent meeting the time conducted by SI(A), the following pro�ile displayed in Figure 1 can schedule.
Observing the soil suitability recommendations by Braiek (2017) and Han (2015), two prominent techniques may be implemented as shown in Figures 5 & 6:
1. Rapid Impact Compaction 2. Dynamic Compaction
A brief description with the principle of both techniques is given as follows:
Rapid Impact Compaction: Rapid Impact Compaction is a cheaper and faster alternative to conventional roller compaction, typically implemented for shallow compaction of soil within a Figure 1: thickness of 5m. The technique is implemented on granular or Soil Pro�ile as per SI(A) coarse-grained soils, however, it may be implemented for soil (a & b). Two pro�iles assessed by SI(B) are presented in the Figure 2 Compaction involves compaction of soil, as a result of energy types with �ine content up to 20%. The principle of Rapid Impact transferred by the repeated free fall of a hammer, on a set grid spacing. The number of blows, height of fall and the set grid are optimized in real-time, as a function of the behaviour of the ground reaction and penetration, to deliver the most optimum results. A work sequence of the Rapid Impact Compaction technique is shown in Figure 3.
a b Figure 2
Although a variation: Soil Pro�iles was observed as determined in the bytwo SI(B) campaigns, a soils,basic whichknowledge required of the compaction. pro�ile was This attained, granular that layer mainly had thickness the sub- surface pro�ile consisted of granular material with lenses of �ine varying from 4m until 7m. The sub-stratum was typically a stiffer Figure 3: Rapid Impact Compaction Work Sequence material and ranged from granular to cohesive material with little Dynamic Compaction: Dynamic Compaction is a cheaper and faster alternative to Vibro-Compaction (VC), typically implemented or noIt softis typicalcohesive for materials investigations predicted to in produce the pro�ile. slightly varying for treatment of soils within a thickness of 8-10m. The technique results. However, by instilling an adequate Front-End Engineering is implemented on granular or coarse grained soils, however, it Design, unexpected conditions may be avoided and a preliminary understanding of the soil conditions in the project can attained The principle of Dynamic Compaction involves compaction of prior (Spyropoulos & Khan, 2020). may be implemented for soil types with �ine content up to 30%. soil, as a result of energy transferred by the repeated free fall of a Heavy Pounder, on a set grid spacing. The number of blows, height of fall and the set grid are optimized in real-time, as a function of the behaviour of the ground reaction and penetration, to deliver
15 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings the most optimum results. A work sequence of the Dynamic Settlement and Bearing Capacity Criteria Compaction method is shown in Figure 4. An embedment of 1.3m was to be considered for the following foun- dation designs shown in Table 2.
Table 2: Foundations considered for Analysis
Type of Footing Footing Size AllowableBearing Allowable Capacity(kPa) Settlement (mm)
Isolated/ 1.0 x 1.0 m2 250 25 Spread 1.5 x 1.5 m2 180 Figure 4: Dynamic Compaction Work Sequence 2.0 x 2.0 m2 145 2.5 x 2.5 m2 125 3.0 x 3.0 m2 110 Strip Width 0.7m 240 Width 1.0m 185 Width 1.5m 143 Width 2.0 m 125
Liquefaction
The following liquefaction criteria was to be achieved after soil im- provement works. • Minimum Factor of Safety against Liquefaction: 1.2 • Peak Ground Acceleration (PGA): 0.07g • Magnitude (M): 4.0
The assessment of Liquefaction Risk Potential was to be carried out implementing Youd et al. (2001). Within the summary report Figure 5: Improvement technique suggestion based on soil type by Youd et al. (2001), it is explained how the Cyclic Stress Ratio is and depth of improvement (Braiek, 2017) determined (implementing average shear stress and stress reduc- tion factor by Seed and Idriss (1971) and Blake (1996), both cited in Youd et al. (2001)). Following which Cyclic Resistance Ratio is calculated for a 7.5 magnitude earthquake (using Rauch (1998) as cited in Youd et al. (2001)). A Magnitude Scaling Factor (after Youd et al. (2001)) is applied to the applicable design and the Factor of Safety is assessed, where resistance is larger than the stress pre- dicted.
Fill Compaction – Performance Line
The compacted �ill was to meet required density based on project speci�ications. Minimum relative density of 85% after �ill compac- Figure 6: Compatibility of techniques based on soil type (Han, Relativetion works density was required is estimated (�ill thickness by reverse of 3m).calculating the required 2015) degree of relative density (Rd) to cone tip resistance (qc) values based on a standard, thereby creating performance lines and com- In an attempt to meet the short project duration, an optimized paring them to the post compaction cone resistance values. For the proposed improvement strategy explained herein, a performance lowing criteria to be achieved by soil improvement works. strategy had to be de�ined. The project design consisting of the fol-
16 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings line for qc values has been developed according to three correlation formulas for relative density of 85% as shown in Figures 7 & 8.
Figure 7: Design Standards considered for Relative Density Figure 8: Target Performance Lines (Rd = 85%) for cone tip resis- Assessment tance (qc) as minimum
Hypothesis preferably two, but can exceed based on soil conditions (Lukas, 1995). In the current hypothesis section, the authors detail the prelimi- − The depth of improvement assessment of Dynamic nary scenario, predicted duration and closing to meet the 6-month Compaction cannot be applied to Rapid Impact Compaction, time duration. instead categorical depth of improvement based on soil type and energy applied should be considered (Han, 2015). Reviewing data from previous studies, Table 3 summarizes general 2 parameters for both techniques. The aim was to attain a minimum of 1,154m of working days (26 days per month) production, with the added time allotted for earth- Table 3: Dynamic Compaction and Rapid Impact Compaction General Production Parameters Equipmentwork �illing wereworks. in vicinity of the site and the mobilization and
Technique Parameter Range Citation set up task could be completed in one working week. As per Khan
Energy 235.25 – 329.35 kJ/m3 (Hussin, 2006) (2019), the rate of production for both techniques may be assumed as follows, Diameter of Tamper: 2.2-2.5m Tamper Weight: 10-40 Tons • Rouaiguia and • Rapid Impact Compaction: 75,000 m2 / month (per rig under General Parameters Grid Spacing: Al-Zahrani (2002) Dynamic 1.5 -2.5x (Tamper Diameter) • Lukas (1995) one shift per day) Compaction Height of Drop: 10-25m • Dynamic Compaction: 35,000 m2 / month (per rig under one (1) NW××× H P shift per day) Energy Estimation E = Lukas (1995) (grid spacing)2 Duration was to be slightly adjusted further for site conditions, soil Energy 150 kJ/m3 (Han, 2015) Diameter of Hammer: 1.5-2.0m conditions and other supplementary factors. Tamper Weight: 9-16 Tons Grid Spacing: In attempt to provide a value engineered design, supplementary Primary: 6 x 6m2 • Chu et al. (2009) pre-investigation works were required. The same would then be Tertiary: 3 x 3m2 Rapid General Parameters • Braiek (2017) (adjusted based on soil conditions, reviewed along with the earthwork design, to effectively segregate Impact • Han (2015) Compaction tamper weight and trial, preliminary grid size shall be assessed areas where either technique would be applicable. In addition to empirically) the same, where applicable, the techniques would be designed in Height of Drop: Up to 1.2m (depending on equipment) combination with one another, to boost production and provide a value engineered design. Energy Estimation Please refer Eq. (1) Lukas (1995) Method – Ground Improvement
Note: The designed testing regime consisted of varying frequency of − Energy = (drop height x weight x number of drops) / soil Piezocone Penetration tests (CPTu) with respect to the areas desig- volume expecting compacted. nated either for structures or for roads. To simplify the same, a fre- quency of 4,000m2 can be considered for each Pre-CPTu as shown − Number of passes should be kept as less as possible, in Figure 9. 17 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Figure 9: Pre-Investigation CPTu Campaign and Segregated Area
Figures 9 & 10 aid in understanding the segregation of areas based on expected soil improvement to be carried out.
Figure 10: Priority Zones and Other Areas of the Project
18 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings Based on the results of the pre-investigation campaign by the soil improvement contractor and the earthworks design, the entire project area was segregated into the following soil improvement scenarios as given in Figure 11.
Stage 1: Dynamic Compaction from Existing Ground Level
Stage 2: Rapid Impact Compaction after Fill Works
Figure 11: Soil Improvement Scenarios Chart
Note: The chart above represents cross-sections of improvement methodology deployed during actual works. The elevations mentioned, are related to the cross-sections with respect to the existing ground level considered 0.0 for the sake of easier understanding. The Final Ground Level on the project ranged from +7.0m to +10.5m.
19 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings The estimated quantities of the scenarios mentioned in Figures 10 Stage 1: Dynamic Compaction to improve existing soil – 16,000m2 & 11 were as follows: Stage 2: 2 • 2 A preliminaryRapid project Impact duration Compaction analysis for �ill was compaction conducted – in-line 16,000m with • Dynamic Compaction after �ill placement: 104,000m 2 the production details previously mentioned, which were further adjusted to site conditions and supplementary factors. The project Rapid Impact Compaction after �ill placement: 76,000m • Dynamic Compaction and Rapid Impact Compaction in duration was limited to 6 months as required and a Gannt Chart for Combination the same is presented in Figure 12.
Figure 12: Preliminary production duration analysis GANNT Chart
Based on the results of the project duration analysis, it was deter- Using a 23 Ton pounder, with 15m height of drop, over a 6 x 6 m2 mined, implementing both Rapid Impact Compaction and Dynamic grid spacing, for a total of 15 blows and 2 passes (discounting the ironing pass), the required energy can be attained. Dynamic Com- Compaction, independently and in combination with one another, paction works were further calibrated during Trials with parame- with just one rig for each technique, the project could successfully ters in a similar range. be complemented in a little under 5 months. Taking a safe estima- tion of two working weeks for Calibration Works, the preliminary Rapid Impact Compaction project duration was assumed to be 5.2 months which was in-line with the fast-track 6-months project requirement. 60× 14.51 ×× 1.1 2 150 = (3) The basis of designing operation parameters for Dynamic Compac- (3.5)2 tion and Rapid Impact Compaction techniques are detailed in Table 3. Based on the same, the following were deduced (subject to ad- Using a 16 Ton Hammer, with 1.1m height of drop, over a 3.5 x 3.5 justment and further calibration during Trial Works). m2 grid spacing, for a total of 60 blows and 2 passes (discounting In the exercise, general parameters based on soil type, expected the ironing pass), the required energy can be attained. Rapid Im- pact Compaction works were further calibrated during Trials with trying to meet energy requirement for both techniques based on parameters in similar ranges. soil behavior and required depth of in�luence were assumed, while minimum energy required, as mentioned in Table 3. Results and Discussion Dynamic Compaction Calibration works were carried out for both techniques considered 15× 20.87 ×× 15 2 in the study. Three grid spacing were considered for the trials of 260.89 = (2) both techniques as follows, (6)2
20 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings • Dynamic Compaction
2 works during calibration works for both techniques considered. • Grid A : 5.0 x 5.0 m Figure 13 (a & b) illustrate the ef�iciency of applied improvement 2 • Grid B : 5.5 x 5.5 m 2 • Grid C : 6.0 x 6.0 m • Rapid Impact Compaction 2 • Grid A : 3.5 x 3.5 m 2 • Grid B : 4.0 x 4.0 m 2 • Grid C : 4.5 x 4.5 m production parameters shown in Table 4, i.e. parameter with which Successful completion of calibration works identi�ied optimum the required soil improvement can be achieved while avoiding overdesign of operations.
Operation parameters adopted for general production Table 4: Figure 13: Pre & Post CPTu at Trial Areas (a) Dynamic works Compaction (b) Rapid Impact Compaction
Technique Production Parameters Grid C: 6 x 6 m2 criteria (as mentioned in section 3) were performed following Soil Improvement works lasted 4.5 month. Veri�ication of design Weight of Pounder: 23 Ton guideline references as mentioned below: Dynamic Compaction Height of Drops: 15m Number of Blows: 15 • Bearing Capacity Assessment: Eslaamizaad and Robertson (1996).
Grid C: 4.5 x 4.5 m2 • Settlement Assessment: Schmertmann et al. (1978). Weight of Hammer: 16 Ton Rapid Impact Compaction • Relative Density: As mentioned in section 3. Height of Drops: 0.9m • Liquefaction Risk Assessment: Based on the summary report on Number of Blows: 60 evaluation of the liquefaction resistance of soils by Youd et al. Note: General production parameters may vary based on soil conditions and soil behavior during actual soil improvement The(2001) achievement as brie�ly of design described criteria in section is shown 3. in Figures 14 to 16. works
Figure 14: Strip foundation bearing capacity and settlement assessment
21 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Figure 15: Isolated foundation bearing capacity and settlement assessment
Figure 16: Liquefaction Risk Assessment
22 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings Following soil improvement works, all design criteria requirements Geotechnical Seminar Field Instrumentation and in-situ Mea- were met by all performed Post CPTu’s, proving the value engi- surements, Nanyang Technological Institute, Singapore, 25–27 neered design of combination of Dynamic Compaction and Rapid November 1986;143–156. Impact Compaction for the current project, a success in terms of 2. Braiek A. Cost effective solution for improving highly heteroge- neous soil. In: 19th International Conference on Soil Mechan- egy. both, the ef�iciency in improving the soil and a time ef�icient strat- ics and Geotechnical Engineering. Seoul. 2017.
Future Research 3. Chu J, Varaksin S, Klotz U, Menge P. Construction processes. In Proceedings of the International Conference on Soil Mechanics Similar to the chart attached in Figure 5 (Braiek, 2017), the authors and Geotechnical Engineering, Alexandria, Egypt. 2009. devised a similar chart to determine value engineering soil im- provement technique based on applicable soil conditions as shown 4. Slaamizaad S, Robertson PK. Cone penetration test to evaluate in Figure 17. bearing capacity of foundation in sands. In Proceedings of the 49th Canadian Geotechnical Conference.1996;429-438.
5. Han, J. Principles and Practice of Ground Improvement. Hobo- ken: Wiley.2015.
6. Hussin, James D. “Methods of Soft Ground Improvement.” The Foundation Engineering Handbook. 2006;529-565.
7. Jamiolkowski M, Lo Presti DCF, Manassero M. Evaluation of rel- Figure 17: Selection of soil improvement technique based in value ative density and shear strength of sands from CPT and DMT. engineering In Soil behavior and soft ground construction.2003;201-238.
Figure 17 includes the inclusion of High Energy Impact Compac- 8. KHAN A. Ground Improvement for Ring Beam Tank Founda- tion (HEIC) and Rapid Impact Compaction (RIC) to the pre-existing tion compared between Vibro Replacement against combina- chart as cost-effective solutions to granular soils. In terms of future tion of Dynamic Techniques with Numerical Models (MENG studies, the authors suggest research into a new technique, which dissertation, Universiti Teknologi Malaysia). 2019. may be called Rapid Impact Replacement (RIR). The aim of the RIR 9. Lukas RG. Geotechnical Engineering Circular No. 1: Dynam- technique is to provide a cost-effective solution to the treatment of ic Compaction. Washington: U.S. Department of transporta- soft cohesive soils to shallower depths, compared to existing tech- tion.1995. niques in the industry today. The authors envision an evolution of the technique from Rapid Impact Compaction, similar to the evolu- 10. Rouaiguia A and Al-Zahrani R. Simulation of Soil Dynamic Com- tion of Dynamic Compaction to Dynamic Replacement. paction. In: The 6th Saudi Engineering Conference. 2002;223- 231. Conclusion 11. Schmertmann JH. Guidelines for Cone Penetration Test, Perfor- In the current paper, a case study was presented for a fast-track mance and Design. Federal Highway Administration, Washing- project, which required the application of soil improvement works ton, DC, USA. Report FHWA-TS-78–209. 1978;145. techniques exist in the market, in an attempt to meet the strict time 12. Schmertmann JH, Hartman JP , Brown PR. Improved strain in- and �ill compaction works in combination. Although a number of duration constraint, the authors devised a value engineered strat- egy, involving the combination of Dynamic Compaction and Rapid Division, ASCE. 1978;104(8):1131-1135. �luence factor diagrams. Journal of Geotechnical Engineering Impact Compaction techniques. A review of the strategy, the design 13. Spyropoulos E, Khan A. Differences between the Geotech- and the project duration analysis was presented in the paper. Fol- nical Campaigns at Front-End Engineering Design (FEED) lowing the same, the results of the campaign were provided, verify- and Detailed Design—A Case Study. World Journal Of Engi- ing the design of the strategy wherein, the project duration require- neering And Technology. 2020;08(4):590-604. doi: 10.4236/ ment was met, and the required design criteria was achieved wjet.2020.84041
References 14. Youd TL, Idriss IM. Liquefaction resistance of soils: sum- mary report from the 1996 NCEER and 1998 NCEER/NSF 1. Baldi G, Bellotti VN, Ghionna N, Jamiolkowski M and Pasqual- workshops on evaluation of liquefaction resistance of soils. ini E. Interpretation of CPT’s and CPTU’s – 2nd part: Drained Journal of geotechnical and geoenvironmental engineering. penetration of sands. Proceedings of the 4th International 2001;127(4):297-313. 23 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Stone Columns as A Remedial Solution to A Compromised Roller Compaction Activity for A Substantial Thickness - Case Study Adil Khan1*, Emmanouil Spyropoulos2, Junaid Ahmad1, Hydar Al-Shokur1
1Soil Improvement Contracting Company, Dammam, Kingdom of Saudi Arabia 2Saudi Aramco, Dhahran, Kingdom of Saudi Arabia
*Corresponding author: Adil Khan, Soil Improvement Contracting Company, Dammam, Kingdom of Saudi Arabia. Email: [email protected]
Abstract The current case study details stone columns construction carried out in response to a geological hazard event instigated by an incompetent layer-by-layer roller compaction activity. The activity was
carried out for substantially thick �ill works of +10m to +11m. The mentioned technique is a considerably unexpected. An extensive redesign of the location was planned which implied expensive construction conservative approach for �ill compaction of such large thickness and the failure occurred was quite activity. A meticulous geotechnical engineer was able to identify the cause and a cost-effective solution for
any activity and the implications of neglecting the same can have i.e. delays, costs and extensive remediation the area. The current case study at its core exempli�ies the importance of adequate quality control during works. At the same time, the paper presents a case study with a geological hazard associated with locally present collapsible soils in Riyadh, the risk they pose and the improvement undertaken to mitigate the risk of future hazards.
Introduction
The study site is located a few kilometres north of Riyadh (KSA) within a cement plant. It consists of a heavy load pavement, which Background underwent a geo-disaster event. The design load of the pavement was supposed to be 60 Ton; however, failure occurred under the Reviewing the data and details of the project, it was theorized self-bearing weight of the constructed platform. Recently placed the deformation occurred due to the presence of water sensitive experienced excessive settlements following a heavy rainfall situated in a location of North of Riyadh known for its presence �ill compacted up to 95% modi�ied proctor dry density (M.D.D.) ofsoils collapsible in the �ill soils pro�ile [1]. Collapsible imported locally, soils are knowing bonded the soils plant with was an was compacted using the conventional and conservative roller open structure that where the particles are in metastable condition. compactionactivity. The inthickness layers of placed150mm �ill to ranged 250mm. from The 10m method – 11m wasand Once collapse agents are active, the bonds break, resulting in a chosen to ensure most optimum results and controlled vibrations, substantial decrease in shear strength, disintegration of the soil as below the area of concern exists a concrete tunnel at a depth of skeletal structure and the subsequent deformation [2]. As per [3, 4] approximately 10m. The total area of the project was 611m2. collapse instigated requires two agents/conditions, i.e. wetting and loading in combination, application of either one without the other A complete re-design of the location was planned in an attempt will not result in a collapse of the full potential. to prevent a similar geo-disaster following a future heavy rainfall event. However, realizing the hazard to be of a geotechnical scope, Collapsible Soils are majorly of two types, Aeolian Soils to ensure the mitigation of risk and understand the actual incident and Residual Soils. In the case of collapsible soils in Riyadh, the occurred, the contractor of the project decided to approach a properties exhibited are more in line with those of Aeolian soils specialist soil improvement contractor to review the case and and they are granular soils with little SILT and medium to well propose remediation works alternate to extensive earthwork and cementation. The cementation found is in varying degrees, but in construction activity. more common cases, the soil is well cemented with stiffness in the
24 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings range of dense to very dense state, when in a dry state. The same Geotechnical solutions* to treat collapsible soil include the soil exhibits substantial collapse upon wetting and a present load. following [2, 6], An example of collapse potential for a site located in Riyadh is given in (Figure 1) [5, 6]. • Soil Compaction. • At Natural Moisture Content. • Compaction with Pre-wetting. • Soil Replacement. • Removal, Replacement and Re-compaction with no foreign material. • Chemical Stabilization.
(*) The above-mentioned methods are solutions to treat collapsible soils, alterations to Foundation and Foundation types are not considered in the current study.
Problem Statement Figure 1: Example of Collapsible Soil potential observed at a site in Riyadh (ACES, 2019) Following a heavy rainfall event and limited ponding, geological failure of excessive settlement occurred beneath the already casted Another way to identify collapsible soils is through their concrete pavement. Substantial settlement of more than 15cm in uncharacteristically low dry density. A preliminary direct test using most places were observed. At most, the recorded settlement was 17.5cm, indicating a non-uniform mechanism of deformation. (Figure 3) chart�ield density to evaluate tests collapse can be potentiala convenient on the way basis for ofearly 2 parameters, identi�ication the dryof presence density andof collapsible the liquid material limit of the in thesample geo-pro�ile tested, [7].as a producedfunction of a it should be noted that the method does not guarantee collapse nor thespeci�ic degree gravity of potential [8]. later collapse; veri�ied it the is primarilyaccuracy of used the forchart, preliminary however identi�ication. (Figure 2)
Figure 3: Measuring degree of soil deformation at current case study area
Reviewing remediation measures, geotechnical analysis of the soil was overlooked initially as the soil was supposedly compacted
discussions and desk-study, geotechnical analysis of the soil was considered.to 95% modi�ied proctor dry density. Upon further internal
A concern with any activity that was to be conducted in the current site, is the presence of an underground concrete tunnel approximately 10m below the area of concern. (Figure 4).
Figure 2: (Holtz and Hilf, 1961) Collapsible and Non-Collapsible soil identi�ication Chart
25 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Figure 6: Proposed Remediation Sketch
Realizing the problem to be of a geotechnical nature. The Contractor of the project approached a specialist soil improvement contractor for their input and suggestive action in ensuring a future heavy rainfall event does not pose a potential hazard. Figure 4: Section: Area of concern with approximate location of concrete tunnel Method – Ground Improvement
Hypothesis Reviewing data provided and pre-existing knowledge of collapsible soils in vicinity, the geotechnical contractor suspected Preliminary understanding was that the geo-disaster occurred something a-miss, considering the soil had been compacted to a as result of heavy rainfall and ponding (see Figure 5). Therefore, 95% M.D.D. The potential of collapse should be negligible compared design and earthwork plans were made to prevent ponding and to original collapse in-situ [1], additionally the dry density assist in drainage. would’ve been uncharacteristically low. Soil investigation tests involving Cone Penetration Tests (CPTs) were carried out to better understand the geological conditions on site. Light green colour
layers. (Figure 7 and 8) signi�ies the presence of SILT layers while dark green signi�ies CLAY
Figure 5: Site Ponding and Deformation
The initial remediation works involved the following steps with
1.some Demolishing dif�icult to achieve of the existing criteria grade as given slab below. area
2. Removal and Re-compaction from Existing Level to -18.3m from Existing Level.
Figure 7: Common trend in Cone Penetration Tests conducted (CPT-02) a. -18.3m till -6.30m, roller compaction to ≥ 95% M.D.D.
c.b. -6.30m-4.50m till -2.50m,-4.50m, roller compaction to =≥ 100%98% M.D.D. M.D.D.
d. -2.50m till 0.00m, reinforced cast insitu concrete (Grade C30/37)
e. Two base course layers placed and compacted at pooling area with slope of 2%, to drain water to ditch. (Figure 6)
26 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
mechanism; however, the operation should be performed vigilantly,
saturated [2]. as additional settlement may occur if the layers are in ef�iciently Apart from the induced collapse and partial replacement, the stone columns created were end bearing i.e. stone columns executed were until refusal. (Figure 9)
. Figure 8: Common trend in Cone Penetration Tests conducted (CPT-04) roller compaction is one of the more established and conservative techniqueOf the that techniques exists implementedpresently. However, in the �ieldapplicability of compaction, of the Figure 9: Load Transfer Mechanism for end bearing reinforce- compaction. Roller compacting cohesive material requires different ments (Kalantari, 2013) rollertechnique types, isvery greatly stringent in�luenced control of moisture by the and material is a considerably expecting
The steps taken in the process of design were as follows (there (Han, 2015). In a general sense, the works conducted was greatly incompatibledif�icult operation with the compared material to placed, select in �ill terms of granular of operation material and soils, researchers may choose their own strategy depending on the equipment employed. Appropriate Quality Assurance and Quality respectiveis no �ixed sitestandard conditions): for the design of stone columns in collapsible Control would prevent the occurred geo-disaster, as anomalies would have been realized at the following stages. • Determining the extent of potential collapseAssessing the
• Testing of Material imported to Site or locally implemented. • Ifintegrity substantial of soil-structure loss of lateral (suf�icient shear lateralstrength shear and strength) subsequent • Post Quality Control tests to verify density. column failure is not envisioned
Due to constraints in soil type and allowable vibrations • Design of Ordinary Stone Columns (End-Bearing), else, (underground concrete tunnel), Vibro-Replacement or Stone Columns was selected as the most applicable technique, due • Design of Encased Stone Columns (End-Bearing). (Figure 10) limited vibrations compared to Dynamic/Impact techniques. More to its �lexibility with soil type, deep depth of improvement and collapse potential as suggested by [9] study on samples collected fromimportantly collapsible Stone soils Columns’ from Borgef�iciency Al-Arab is exempli�ied area, Alexandria, in mitigating Egypt [Han, 2015, 10].
Majority of the previous studies reviewed implemented models Figure 10: Applicable Stone Columns Technique Decision Making Chart collapsible soils. Stone columns can be constructed in two ways, the dryor simulations method or tothe verify wet methodthe ef�iciency (the dry of stonemethod columns is not inapplicable treating in all locations, due limitations in penetration). As suggested by The soil at the site was determined to possess collapsible [2] and internal analysis by the contractor’s technical team, by potential of the medium category. The decision to validate the performing the wet method of penetration a better induction of integrity of the soil during stone column construction is based on pre-collapse was predicted via simulation and a large collapse was both the expected soil behaviour and judgment of the engineer. Unfortunately, Plaxis does not take into account matric suction not envisioned. Vibro-�lotation can greatly enhance pre-collapse 27 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings which is basically one of the governing criteria in the unsaturated on the fact that the soil was of medium collapsible potential and to saturated behaviour of the soil. Implementing the Soil Water Characteristic Curve, the geotechnical designer modelled the effect of inundation in different stages, each representing a state constructionthe favourable of ordinary simulation stone results, columns, the subject �inal decision to a trial was column that of saturation and respectively adjusted geotechnical properties of construction.the soil would A havetrial suf�icientwith the installation lateral shear of strengtha single tocolumn allow was the the soil layers. Cavity Expansion method was used to model the made prior to the actual production works. installation of a single column to effectively simulate the generation of pore pressures in the soil layers and subsequent behaviour. Design of the columns were carried out as per DIN 4017-1:2006- The created model was made with multiple assumptions so there 3 [11] for the estimation of Bearing Capacity and [12] for the was a need for a trial. The decision was of the design engineer to calculation of estimated settlement of end-bearing stone columns. give a judgment if the generated in-house model and results were acceptable or a geotechnical failure could be foreseen. Based summary of the composite geotechnical properties and the results ofThe preliminary design was analysis subsequently are given veri�ied below. using [Table Elastic 1] Theory [13]. A
Table 1: Composite Soil Geotechnical Properties
Layer Zsup (m) Zinf (m) Es (MPa) Ms (MPa) Øc (m) Ac (m)
1 0.0 0.3 65.0 νs0.33 γs20 (kN/m3) 97.5 0.90 0.64 τ12.5 (%) 2 0.3 1.3 60.0 0.33 19 90.0 0.90 0.64 12.5 3 1.3 2.3 27.6 10.33 18 41.4 0.90 0.64 12.5 4 2.3 3.3 27.6 0.33 18 41.4 0.90 0.64 12.5 5 3.3 4.3 27.6 0.33 17 41.4 0.90 0.64 12.5 6 4.3 5.6 12.8 0.33 17 19.2 0.90 0.64 12.5 7 5.6 7.0 12.8 0.33 17 19.2 0.90 0.64 12.5 8 7.0 8.3 12.8 0.33 17 19.2 0.90 0.64 12.5 9 8.3 9.7 12.8 0.33 17 19.2 0.90 0.64 12.5 10 9.7 11.0 12.8 0.33 17 19.2 0.90 0.64 12.5
In relation to Table 1, the abbreviations and symbols are encased stone columns. Further studies are encouraged involving described below, implementing Stone Columns in the treatment of collapsible soils, as presently the topic is to a certain extent unexplored. (Figure 12) • Zsup: Top of Layer gives an insight on the available research/study that exist presently.
• Zinf: Bottom of Layer
• Es: Elastic Modulus
• νs: Poission Ratio
• Ms:γs: Unit Oedometric Weight Modulus
• Ac:⌀c: DiameterArea of Column of Column Figure 11: Preliminary Design Analysis Excerpt
(Figure• τ: 11)Replacement It should be Ratio noted, adequate analysis and numerical modelling should be undertaken prior to construction. As mentioned in Section 2, if substantial loss of lateral shear strength is envisioned, alternative techniques may be reviewed, such as geo-synthetic
28 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Figure 12: Percentage-wise available studies recorded in 2017 (Al-Obaidy, 2017)
Stone Column were designed on the comparably worse soil conditions as given below. [Table 2]
Table 2:
Soil Pro�ile considered for Improvement Elevation M.S.L.(m) Cone Tip Resistance Top of Layer Bottom of Layer Thickness (m) Average (MPa) Soil Type
Gravelly SAND to SAND 593.7 592.4 1.3 20.0 Slightly silty SAND to SAND (with pockets of GRAVEL) 592.4 591.2 1.2 11.0
SAND to silty SAND 591.2 589.4 1.8 8.0 (with pockets of SILT) Silty SAND to sandy SILT 589.4 587.7 1.7 5.5 Silty SAND to sandy SILT 587.7 586.4 1.3 2.5 Silty SAND to sandy SILT 586.4 582.7 3.7 5.0 SAND to slightly silty SAND 582.7 577.7 5.0 >30.0
The design criteria to be achieved following construction was as given below,
• Allowable Bearing Capacity > 100kPA
• Allowable Settlement limit < 50mm
AIn critical line with aspect the requirementof the operation and is conditions, controlled Stonevibrations Columns with of respect the con�iguration to the underground mentioned concrete in [Table tunnel. 3] were British designed. Standards Institution Table 3: Stone Columns’ Design Parameters
Structure Applied Pressure Minimum Average Uniform Replacement Calculate Allowable (kPa) Diameter of Length of Square Ratio Settlement Bearing Column Column Grid (%) (cm) Capacity (m) (m) (m x m) (kPa)
Concrete 100 0.90 9 – 11.5 2.26 x 2.26 12.5 42.0 294 Pavement
29 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
(1993) recommends working limits for allowable peak particle velocity as given in Table 4
Table 4: Vibration Monitoring Limits suggested by British Standards Institution (1993)
Structure Allowable PPV 4Hz to 15Hz >15Hz Reinforced or framed structures, industrial and heavy 50mm/s commercial buildings Un-reinforced or lightly framed structures and resi- 15mm/s at 4Hz increas- 20mm/s at 15Hz increasing to dential or light commercial type buildings ing to 20mm/s at 15Hz 50mm/s at 40Hz and above
The maximum allowable limit was set at 20mm/s. Tests were Table 5: conducted during Trial Works at 3 different locations as follows. Soil Pro�ile considered for Improvement Peak Particle Velocity • Test No. 01 (Inside Tunnel): Performed under the stone column number SC-004. Radial Transverse Vertical Description / Location • Test No. 02 (Existing Ground): Performed at a distance of Test No. 01 (Inside 0.889 0.381 0.1905 6.0m apart from stone column number SC-018. Tunnel)
• Test No. 03 (Inside Tunnel): Performed under the stone Test No. 02 (Existing 14.755 12.588 12.779 column number SC-064. (Figure 13) Ground) Test No. 03 (Inside 0.254 0.254 0.1905 Tunnel)
Stone Column construction was carried out using the wet- method followed by a successful trial as discussed in Section 5. The entire operation was a time effective solution. The complete setup, from mobilization until completion, lasted 18 working days, with the actual works completed in just a total of 7 working days as shown in (Figure 14).
Figure 13: Vibration Monitoring Testing Plan
Results and Discussion
Prior to actual operations, trial works were carried out for usingspeci�ic NOMIS columns Mini graph with vibration7000. monitoring in parallel at the locations speci�ied in the previous section. Testing was carried out Results of the monitoring were satisfactory, with the highest recording below the 20mm/s PPV limit with the results as given in Table 5. Figure 14: Stone Columns construction in progress
To put things in perspective, for the conservative approach, after the demolition of the existing concrete pavement, all the material would have to be excavated, removed and replaced. The replaced material would have to be of higher quality i.e. AASHTO A-1-a, to be compatible with Roller Compaction. Apart from a
30 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings slower production, the conservative approach would also prove as include a comparative analysis of prewetting in combination to an expensive alternative. compaction and no pre-treatment compaction, with the level of
Following the construction of the columns, quality control Plate Load Test (PLT) was performed. The maximum applied load was 1.5 Conclusionef�iciency veri�ied for both operations. times the design load. The results of the test were satisfactory and in line with the design criteria as illustrated in (Figure 15). The current paper emphasized the vulnerability of inadequate poor execution and quality control to a well-designed plan, demonstrated in the case study with the occurrence of a geo- disaster event. Layer wise roller compaction is the more conservative approach and in the case of the current project
expensive option. Investigations conducted revealed the presence with �ill thicknesses greater than 10m, it was likely even a more of compaction carried out. The operation was unsuccessful due to of largely unsuitable material (very high �ine content) for the type
insuf�icientApart from quality the of above,works. the geo-disaster failure mechanism indicated soils possessing collapsible potential present in the case study area. The most applicable ground improvement technique was chosen as Stone Columns (or Vibro-Replacement) due to its Figure 15: Post-Plate Load Test Results propagation compared to alternative techniques. Studies regarding With the help of a load test, the designer is able to verify the �lexibility with applicable material, comparably lower vibration column has mobilized and was not affected due to the presence opinionated with varying degrees of success. Taking the recommendationsproven ef�iciency of were most limited, researchers with in a the number type of operation researchers to mitigated the risk of collapse potential. of collapsible soil and in-return reinforced the soil pro�ile and in the case of suspected collapsible material (wetting used for Future Research penetrationbe adopted (Wet-Method),stage to be extended the modi�ications and careful to vigilance general operations to ensure
The authors suggest the involvement of geotechnical engineers be end-bearing in design), ensured mitigating risk of suspected involved in Horticulture to provide their valuable input and collapsibleuniform wetting) soils, usually and the found design in Riyadhof the �inal(KSA). columns (columns to expand existing knowledge further regarding collapsible soils. Horticulture engineers are quite well versed with subject matters Reference such as unsaturated soil mechanics, soil-water partial saturation 1. Alawaji HA. Model plate-load tests on collapsible soil. Journal of King Saud University-Engineering Sciences. 1998;10(2):255- groundwater, etc., all of which are closely related to understanding 269. collapsiblecharacteristics soils. and behaviour, in�iltration and evaporation of 2. Al-Rawas AA. State-of-the-art-review of collapsible soils. Sultan Another suggestion is a subject for future research, involving Qaboos University. Journal for Science [SQUJS]. 2000;5:115- 135. cemented collapsible soils. The presence of collapsible soils 3. Murthy V. Advanced Foundation Engineering (1st ed.). New verifying the ef�iciency of impact-based compaction to highly with strength that are very high in strength (NSPT > 50), usually Delhi: CBS Publishers & Distributors. 2007. mistaken for a type of rock or intermediate geomaterials, are 4. Rollins KM, Rogers GW. Mitigation measures for small in treating collapsible soils; however, most the research available structures on collapsible alluvial soils. Journal of Geotechnical Engineering. 1994;120(9):1533-1553. presentlyusually identi�ied includes in soil Riyadh. of medium Compaction to medium-well is a cost-effective cemented method soils, examples given below. 5. ACES. Geotechnical Report – Phase 01: Riyadh Township. Print. 2019. • Dynamic Compaction: Collection of Case Histories in Treating Collapsible soils with strengths in the loose to medium dense 6. Roshdy M. Treatment of Collapsible Soil (M.Sc.). Ain Shams category [14]. University. 2014. 7. Holtz WG, Hilf JW. Settlement of soil foundation due to • Rapid Impact Compaction: Treatment of Collapsible soils in saturation. Proceedings of the 5th International SMFE, Paris, Karachaganak region, Kazakhstan [15]. France. 1961;1.
8. presence of stiff geo-material (Han, 2015). The research could neural networks. Geotechnical & Geological Engineering. The ef�iciency of compaction decreases signi�icantly with the 2004;22(3):427-438.Basma AA, Kallas N. Modeling soil collapse by arti�icial 31 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings 9. Ali NA. Performance of partially replaced collapsible soil–Field 14. Rollins KM and Kim J. Dynamic compaction of collapsible study. Alexandria Engineering Journal. 2015;54(3):527-532. soils based on US case histories. Journal of geotechnical and geoenvironmental engineering. 2010;136(9):1178-1186. 10. Chan L, Sully J, Parra E, Scott J and Higginbottom K. Ground Vibrations and Deformations Associated with Stone Column 15. Synac O and Serridge CJ. Application of the Rapid Impact Installation. In: PAN-AM CGS. Richmond, BC. 2011. Compaction (RIC) technique for risk mitigation in problematic soils. In The 10th IAEG International Congress, Nottingham, 11. DIN ISO. Soil - Calculation of design bearing capacity of soil United Kingdom. 2006;1-13. beneath shallow foundations (DIN 4017:2006-03). Berlin: DIN Beuth Publishing. 2006. 16. Al-Obaidy N. Treatment of Collapsible Soil Using Encased Stone Columns. Doctor of Philosophy. University of Birmingham. 12. Priebe HJ. The design of vibro replacement. Ground engineering. 2017. 1995;28(10):31. 17. British Standards Institution. BS7385-2:1993 Evaluation and 13. CEN. EN 1997-1:2004. Eurocode 7 Geotechnical design - measurement for vibration in buildings - guide to damage Part 1: General rules. Brussels, European Committee for levels from groundborne vibration. London: BSI. 1993. Standardization. 2004. 18. Kalantari B. Foundations on collapsible soils: a review. Proceedings of the Institution of Civil Engineers - Forensic Engineering. 2013;166(2):57-63. doi: 10.1680/feng.12.00016
32 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Web Crippling Investigations of Aluminium Lipped Channel Sections with Web holes – End-Two-Flange Loading Conditions
H Alsanat*, S Gunalan1, P Keerthan2
1
2Faculty of Engineering and Environment, University of Northumbria, Newcastle, UK Senior Lecturer, Grif�ith University, School of Engineering & amp; Built Environment, Grif�ith University, Nathan, Australia *H. Alsanat , Assistant Professor, AHU University, teaching Structural Analysis, Steel Design, Reinforced Concrete Design, Jordan
*Corresponding author: H. Alsanat , Assistant Professor, AHU University, teaching Structural Analysis, Steel Design, Reinforced Concrete Design., Jordan, Email:
Abstract The use of aluminium as a building material and load-bearing member has increased considerably due to their unique characteristics as a highly ductile, recyclable and corrosion-resistant material. While its structural potential is still being elucidated, its modulus of elasticity is inferior to that of steel. Hence it is more vulnerable to certain types of buckling instabilities such as web crippling. Web crippling failure occurs in thin-walled members including lipped channel beams, which can be found in the structural system as joists or rafters where transverse forces may arise. Recently the authors have thoroughly investigated the web crippling behaviour and design of roll-formed aluminium lipped channel sections subjected to web crippling. However, in real-life applications, holes in the web maybe
required for the installation of electrical or plumbing services, which could have a great in�luence on the web crippling capacity of the member. Such in�luence has not been investigated yet, thus this study is conducted to experimentally explore the in�luence of web openings on the web crippling characteristics of these sections under the end-two-�lange loading conditions. Fifteen specimens with Design recommendations in the form of web crippling strength reduction factor are proposed in this various hole sizes are tested as speci�ied by the American Institute of Steel and Iron (AISI) standard. study.
Keywords: Aluminium; Lipped Channel Sections; Web Crippling; Web opening; Reduction Factor
1. Introduction Over the last years, aluminium alloys have become more attractive against web shear buckling failure by Rouholamin et al. [6,7]. in construction as a structural material. The high ductility, durability, The mechanical properties and residual stresses of ALCB’s were corrosion resistance, strength-to-weight ratio, workability and thoroughly explored by Pham and Rasmussen [8]. In practice, it might be necessary to punch in the web of aluminium production used in construction. Aluminium sections, structural members for the installation of the plumbing and/ suchmany as other Channels inherent and properties Zed sections, have fabricated led to signi�icantly using the roll-formingincrease the or electrical systems. The presence of such holes may lead to a technique have been utilised as purlins, girts and beams in structural systems were harsh marine and industrial environments dominate. reduced strength is needed. Uzzaman et al. [9–12] and Lian et al. BlueScope Permalite Australia is producing these sections using signi�icant reduction to the section strength and the prediction of 5052-H36 aluminium alloy grades due to the exceptional corrosion of web circular opening on the web crippling capacity of cold-formed resistance against saltwater and spray. steel[13–16] channel experimentally sections under and numericallyall load cases. investigated Further, Uzzaman the in�luence et al. To date, the buckling instabilities of roll-formed aluminium [17-18] have recently reported web crippling tests and numerical sections have not been thoroughly investigated. Alsanat et al [1-5] analyses on cold-formed steel channel sections with edge-stiffened studied the localized buckling (web crippling) failure of aluminium circular web holes under various loading conditions. For stainless- lipped channels (ALC) sections under all possible load cases (end- web crippling capacities of cold-formed lipped channel sections withsteel circular sections, web Youse�i openings et al. using [19,20] both studied experimental the reduction and numerical in the one-�lange (EOF), interior-one-�lange (IOF), end-two-�lange (ETF) and interior-two-�lange (ITF)). These beams were also investigated 33 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings scheme. Zhou and Young [21] performed a combination of Note: specimen names end with (a) or (b) were repeated tests experiments and numerical analyses on extruded aluminium hollow 2.2. Material properties conditions. All the aforementioned studies proposed reduction The mechanical properties of the roll-rolled channel sections factorssections to subjectedestimate the to reduced web crippling web crippling under capacity two-�lange due loading to the were investigated using coupon tests. Flat coupons were taken from opening. In the literature, however, no research has been conducted bottom). All coupons were cut in the longitudinal direction (parallel capacity of roll-formed aluminium lipped channel sections. It is also tothe the�lat portionrolling direction),of the web atThe different dimensions positions of the(upper coupons middle were and believedto investigate that the the available in�luence design of web guidelines opening will in thefail webto predict crippling the 12.5mm wide and 50 mm long. The coupons were then tested in actual capacities of these sections due to their empirical nature. Instron tensile testing machine, and yield stress (σ0.2) and Young’s The present study aims to determine the effect of web opening modulus (E) (given in Table 1) were acquired from the stress-strain curve, Figure 2 show the typical stress-strain curve for a typical on the web crippling capacity of roll-formed ALC sections under coupon cut from section 250-2.5. scenarios. A Series of tests was carried out on the sections with ETF loading condition with both unfastened and fastened �lange holes located at the mid-depth of the web. The experimental data was then used to propose a reduction factor equation to determine the reduced capacity. Statistical veri�ication was performed to con�irm the accuracy of this factor, and showed a good agreement of2. data,Experimental with an acceptable investigation coef�icient of variation. 2.1. Test specimens In total, 16 lipped channels with and without openings were prepared and tested. The test specimens were roll-formed using 5052-H36 aluminium sheets. Sections with 250 mm depth, 2.5 mm and 3 mm thicknesses and 5mm inside bent radius (ri) were Figure 2: Typical stress-strain curve for 5052-H36t on the web crippling capacity, opening with nominal diameters (a) rangingconsidered from herein. 50, 120 To and investigate 190 mm the were in�luence perforated of the in webthe web. opening The 2.3. Test rig and procedure opening diameter a h) ratios (a/h) were 0.2, 0.5, and 0.8. All openings were located, where their to the �lat portion of the web depth ( ALC sections were tested under ETF loading condition. Figures According to the AISI S909 [23] speci�ication guidelines, the offsite between the opening perimeter and specimen’s end. The 3(a) and (b) depict the test set-up for unfastened and fastened specimensin�luence is length optimal; (L the mid-depth of the webs and3h 50), accordingmm �ixed to The AISI S909 [23] Standard test method. Table 1 summarises identical and high strength bearing plates. The bottom and top tests, respectively. The specimen was �irst positioned between two the measured sectional) is threedimensions times theof the�lat depthspecimens ( which are accurately measured using a tap meter, micrometre vernier, and plates using M12 bolts for fastened scenario while they were kept unrestrained�langes at the for end the ofunfastened the specimen scenario. were Half attached rounds towere the attached bearing channel sections with holes. to the bearing plates to simulate hinge support. MTS machine with calliper. Figure 1 shows the typical sectional pro�ile for lipped 500 kN capacity was used to apply a load by driving a hydraulic For specimen designation, a label was given for each specimen cross-head downward with a constant rate of 2mm/min. The as presented in Table 1. For example, the label F- 250-3-A0.5 can applied force and the vertical movement were precisely recorded be explained as: fastened condition (F), loading condition (ETF), using a data-acquisition system. Figures 4 (a) and (b) present the section depth (250), section thickness (3) and the hole ration (A0.5). load-vertical displacement curve for ALC sections with different The letter “U” indicates the unfastening loading conditions. hole ratios.
3. Proposed web crippling reduction factor
S100(Equation (1)) for cold-formed steel lipped channel sections to accuratelyAlsanat et predict al. [1,3] the modi�iedweb crippling the equationcapacity for provided unfastened by AISIand fastened ALC sections with no holes under the ETF. The effect of
C, CR, CN and Ch)were elasticproposed moduli and givenof aluminium in Table alloys2. was incorporated in the modi�ied Equation (2), and the new coef�icient factors
(1) Figure 1: channel sections with holes Typical sectional pro�ile for lipped 34 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings Table 1: Geometric and mechanical properties of tested ALC sections N t r l L E f P Specimen d (mm) b (mm) i b y Exp. (mm) (mm) f (mm) (mm) (mm) (MPa) (MPa) (kN)
U-ETF-250-3-A0(a) 100 253.2 2.95 72.2 5.0 25.0 716 65050 210 5.1
U-ETF-250-3-A0(b) 100 253.7 2.93 76.7 4.8 24.8 716 65050 210 5.0
U-ETF-250-3-A0.2(a) 100 252.4 2.94 76.7 4.8 24.9 716 65050 210 4.8
U-ETF-250-3-A0.2(b) 100 252.3 2.94 76.9 5.0 23.7 714 65050 210 4.7
U-ETF -250-3-A0.5 100 253.5 2.97 77.2 4.8 23.6 715 63555 206 3.9
U-ETF -250-3-A0.8(a) 100 254.0 2.94 77.7 4.8 25.6 714 63555 206 3.0
U-ETF -250-3-A0.8(b) 100 262.1 2.44 76.2 4.8 22.7 715 63555 206 3.1
U-ETF -250-2.5-A0 100 252.8 2.44 76.2 5.0 25.1 713 63555 206 3.8
U-ETF -250-2.5-A0.2 100 252.4 2.55 76.0 5.0 25.3 714 63955 214 3.1
U-ETF -250-2.5-A0.5 100 252.2 2.44 76.2 5.0 25.1 1440 63955 214 2.4
U-ETF -250-2.5-A0.8 100 252.5 2.94 76.8 5.0 25.6 714 63955 214 2.0
F-ETF -250-3-A0 100 253.7 3.00 76.5 4.8 24.6 711 63955 214 8.1
F-ETF -250-3-A0.2 100 252.9 2.99 76.9 4.8 25.6 714 64125 212 7.6
F-ETF -250-3-A0.5 100 253.2 2.93 76.6 5.0 24.5 716 64125 212 6.5
F-ETF -250-3-A0.8 100 253.7 2.95 72.2 5.0 25.0 716 64125 212 4.4
(a) Unfastened - ETF (b) Fastened - ETF Figures 3: web crippling test set-up
(a) unfastened - ETF (b) Fastened - ETF Figures 4: load-vertical displacement curves for ALC specimens with different hole ratios
35 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
(2)
Where C CR CN and Ch is the web crippling overall coef�icient,r is the coef�icient of the 0internal corner radius, is the coef�icient of the bearing length hN≤≤200, 210 i ≤ 3 N ≤ 2 θ = 90 is the coef�icient of thett slenderness of the tweb. The hvalues of these coef�icients are summarised in Table 2. Note that in Equation (1), the following conditions , , , and must be satis�ied. Table 2:
Flange condition LoadAlsanat case et al.’s [1,3]C web cripplingtC Rcoef�icients forCN ALC sections Ch
Unfastened ETF 0.273 0.21 0.16 0.06 0.90 Fastened ETF 0.231 0.21 0.35 0.05 0.91
For the test specimens, the web crippling strengths of the sections without the web holes were obtained. Thus, the ratio of the web crippling strengths for sections with the web holes divided by the sections without the web holes, which is the strength reduction factor (R),
Evaluation of the experimental results shows that the ratios a/h thewas sections used to quantifywith web the holes degrading as shown in�luence in Figure of the5. The web reduction holes on inthe the web web crippling crippling strengths capacity under can reach the end-two-�lange up to 43% of specimens loading condition. without is the primary parameters in�luencing the web crippling behaviour of web holes. Based on the experimental results obtained from this study; strength reduction factor (Rprop) is proposed using bivariate linear regression analysis for the end-two-�lange loading condition. (3)
Table 3: Accuracy data for the proposed ETF web bearing capacity reduction factor
Specimen PExp. R Rprop. R/Rprop.
U-ETF-250-3-A0(a) 5.1 1.00 1.00 1.00 U-ETF-250-3-A0(b) 5.0 0.98 1.00 0.98 U-ETF-250-3-A0.2(a) 4.8 0.94 0.89 1.06 U-ETF-250-3-A0.2(b) 4.7 0.92 0.89 1.04 U-ETF -250-3-A0.5 3.9 0.76 0.73 1.05 U-ETF -250-3-A0.8(a) 3.0 0.59 0.58 1.02 U-ETF -250-3-A0.8(b) 3.1 0.61 0.58 1.05 U-ETF -250-2.5-A0 3.8 1.00 0.98 1.02 U-ETF -250-2.5-A0.2 3.1 0.82 0.88 0.94 U-ETF -250-2.5-A0.5 2.4 0.64 0.73 0.88 U-ETF -250-2.5-A0.8 2.0 0.53 0.57 0.93 F-ETF -250-3-A0 8.1 1.00 1.00 1.00 F-ETF -250-3-A0.2 7.6 0.94 0.89 1.06 F-ETF -250-3-A0.5 6.5 0.80 0.73 1.10 F-ETF -250-3-A0.8 4.4 0.54 0.57 0.95 Mean 1.01 COV 0.06
36 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
3. H Alsanat, S Gunalan, P Keerthan, H Guan, C Baniotopoulos. Fastened Aluminum-Lipped Channel Sections Subjected to Web Crippling under Two-Flange Loading Conditions: Experimental Study. J Struct Eng. 2020;146(4):04020023.
4. H Alsanat, S Gunalan, P Keerthan, H Guan, KD Tsavdaridis. Numerical investigation of web crippling in fastened
loading conditions. Structures. 2020;23:351–365. aluminium lipped channel sections under two-�lange 5. H Alsanat, S Gunalan, P Keerthan, H Guan. Web Crippling Investigations of Aluminium Lipped Channel Sections under One-Flange Loading Conditions. Thin-walled Struc. 2019;144:106265.
6. M Rouholamin, S Gunalan, K Poologanathan, H Karampour. Experimental study of roll-formed aluminium lipped channel beams in shear. Thin-Walled Struct. 2020;153:106687. Figure 5: Variation in reduction factors with a/h 7. M Rouholamin, S Gunalan, K Poologanathan, H Karampour. Shear design rules for roll-formed aluminium lipped The web crippling reduction values (Rprop.) predicted by Equation (3) agree well with the experimental web crippling reduction values channel beams. Structures. 2020;27:1139–1164. (R) of ALC sections under the ETF load case, as evidenced in Table 3. The mean value of of the sections is 1.01 with a COV of R/Rprop. 8. LAT Huynh, CH Pham, KJR Rasmussen. Mechanical 0.06. Figure5 compares the experimental reduction results of the ALC sections with the predictions using the proposed Equation (3) properties and residual stresses in cold-rolled aluminium under the ETF load case; from which the suitability of the proposed channel sections. Eng Struct. 2019;199:109562.
9. A Uzzaman, JBP Lim, D Nash, J Rhodes, B Young. Web 4.equation Conclusions is con�irmed. crippling behaviour of cold-formed steel channel sections
This paper presents an experimental web crippling study of roll- loading. Thin-Walled Struct. 2012;50(1):76–86. formed aluminium lipped channel sections with/without web holes with offset web holes subjected to interior-two-�lange 10. A Uzzaman, JBP Lim, D Nash, J Rhodes, B Young. Cold- scenarios were considered. Fifteen specimens were tested and the formed steel sections with web openings subjected to under end-two-�lange load case. Both unfastened and fastened reduction in the web crippling capacity can reach up to 43% of in�luence of web hole-to-section depth ratio was investigated. The web crippling under two-�lange loading conditions—part specimens without web holes. Based on the experimental data, web 2012;56:38–48. I: tests and �inite element analysis. Thin-Walled Struct. crippling strength reduction factor equation was proposed for the Unfastened/fastened ETF load case. The comparison between the 11. A Uzzaman, JBP Lim, D Nash, J Rhodes, B Young. Cold- formed steel sections with web openings subjected to experimentaland reliability and of the proposed proposed reduction equation. factor con�irms the accuracy II: parametric study and proposed design equations. Thin- web crippling under two-�lange loading conditions—Part Walled Struct. 2012;56:79–87. References 12. A Uzzaman, JBP Lim, D Nash, J Rhodes, B Young. Effect of 1. H Alsanat, S Gunalan, H Guan, P Keerthan, J Bull. offset web holes on web crippling strength of cold-formed Experimental study of aluminium lipped channel sections condition. Thin-Walled Struct. 2013;65:34–48. Thin-Walled Struct. 2019;141:460–476. steel channel sections under end-two-�lange loading subjected to web crippling under two �lange load cases. 13. Y Lian, A Uzzaman, JBP Lim, G Abdelal, D Nash, B Young. 2. H Alsanat, S Gunalan, P Keerthan, H Guan, KD Tsavdaridis. Effect of web holes on web crippling strength of cold- Web crippling behaviour and design of aluminium lipped
formed steel channel sections under end-one-�lange Thin-Walled Struct. 2019;144:106265. analysis. Thin-Walled Struct. 2016;107:443–452. channel sections under two �lange loading conditions. loading condition – Part I: tests and �inite element 37 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
14. Y Lian, A Uzzaman, JBP Lim, G Abdelal, D Nash, B Young. design for edge-stiffened holes, unstiffened holes and Effect of web holes on web crippling strength of cold- plain webs. Thin-Walled Struct. 2020;147:106532.
loading condition - Part II: parametric study and proposed 19. formed steel channel sections under end-one-�lange B Young. Design of cold-formed stainless steel lipped design equations. Thin-Walled Struct. 2016;107:489–501. AM Youse�i, JBP Lim, A Uzzaman, Y Lian, GC Clifton, channel sections with web openings subjected to web 15. Y Lian, A Uzzaman, JBP Lim, G Abdelal, D Nash, B Young. Web crippling behaviour of cold-formed steel channel Struct Eng. 2017;20(7):1024–1045. crippling under end-one-�lange loading condition. Adv
loading condition-Part I: experimental and numerical 20. sections with web holes subjected to interior-one-�lange Numerical investigation of web crippling strength in cold- investigation. Thin-Walled Struct. 2017;111:103–112. AM Youse�i, A Uzzaman, JBP Lim, GC Clifton, B Young. formed stainless steel lipped channels with web openings 16. Y Lian, A Uzzaman, JBP Lim, G Abdelal, D Nash, B Young. Web crippling behaviour of cold-formed steel channel Compos Struct. 2017;23(3):363–383. subjected to interior-two-�lange loading condition. Steel
loading condition – Part II: parametric study and proposed 21. F Zhou, B Young. Web crippling of aluminium tubes with sections with web holes subjected to interior-one-�lange design equations. Thin-Walled Struct. 2017;114:92–106. perforated webs. Eng Struct. 2010;32(5):1397–1410.
17. A Uzzaman, JBP Lim, D Nash, B Young, Effects of edge- 22. for the cold-formed steel structural members. Washington stiffened circular holes on the web crippling strength American Iron and Steel Institute AISI S100. Speci�ications DC, USA. 2016. loading conditions. Eng Struct. 2017;139:96–107. of cold-formed steel channel sections under one-�lange 23. American Iron and Steel Institute AISI S909. Standard 18. A Uzzaman, JBP Lim, D Nash, K Roy. Cold-formed steel test method for determining the web crippling strength of cold-formed steel beams, Washington DC, USA. 2008.
channel sections under end-two-�lange loading condition:
38 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Mathematical Prediction of the Structural Substance of Asphalt Pavements as a Prerequisite for Economical Maintenance
Jörg Patzak*
*Professor of Traf�ic Route Engineering at Beuth University of Applied Sciences Berlin, Germany *Corresponding author: Jörg Patzak, Professor of Traf�ic Route Engineering at Beuth University of Applied Sciences Berlin, Germany, Email:
Abstract Since the introduction of the guidelines for mathematical dimensioning of foundations
possible to determine the layer thicknesses of pavements individually based on a computational of traf�ic surfaces with a course asphalt surface (RDO Asphalt) [1] in 2009 in Germany, it is dimensioning process. In the opposite case, the structural substance of existing asphalt pavements can be predicted and valuated by calculation (RSO Asphalt, draft 2016) [2]. The aim is to calculate the structural substance expressed by the remaining service life of an asphalt pavement, with the focus of the asphalt base. The knowledge of the remaining service life of an asphalt pavement is the crucial basis for sustainable and economical maintenance. The planning of an economical service life can be realized only then, if the service life of the remaining asphalt layers is adjusted to the renewed layers. The basis for the application of this method is the knowledge of the existing pavement structure and the performance parameters of all asphalt materials in the existing pavement. That means in detail the master curves and the fatigue function. Additional to that, the
traf�icThis load new and method the climate and the conditions application are in the practice main ininput combination factors. with a new developed software solution called Analysing and Design Tool for Pavements (ADtoPave) especially developed for pavement engineering are introduced in this paper.
1. Introduction
Compared to the conventional empirically dimensioning service life which can be realized only then, if the service life of the method according to the RStO [4], the guidelines for mathematical remaining asphalt layers is adjusted to the renewed layers. asphalt surface (RDO Asphalt) [1] in 2009, brought an essential step 2. Valuation of the structural substance of asphalt dimensioning of foundations of traf�ic surfaces with a course pavements 2030, the government primarily focuses on the maintenance with to a sustainable and economical maintenance. In the traf�ic forecast 2.1 Basics of this method necessary to evaluate the structural substance of pavement in 69 % of the available �inancial resources. Therefore, it is absolute The application of this method based mainly on the following advance of maintenance decisions. four work packages, which will be explained later in this paper.
The basis for this is a process that enables the evaluation of the I. Determining of homogeneous road sections, called structural homogeneous sections. draft 2016) [2]. It is important to point out that this process structural substance of asphalt pavements in �ield (RSO Asphalt, does not focus on surface features but on the internal condition II. Extraction of drill cores in the structural homogeneous of the pavement. Exactly that is the foundation of an economical sections.
39 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
III. Material testing to determine the performance parameters (stochastically modelled) will be considerate. The result is the of all asphalt materials in the existing pavement. probability of default of the investigated section. It is also possible to predicates the probability of default so that the remained years IV. Evaluation of the structural substance with the deterministic procedure or with the probabilistic differences between these procedures are shown in the following to reach the de�ined probability can be calculated. The main procedure. steps.
2.2 Structural homogeneous sections 3. Examples The pavement to be investigated has to be divided in section, with a homogeneous character. Homogeneous at this point means section of a federal road with a length of approximately 1200 m. Speci�ic example at this point is a structurally homogeneous conditions and the same age of the asphalt layers for instance. no changes in the kind of construction, the same traf�ic and climate For the calculation of the structural substance a new software called Analysing and Design Tool for Pavements (ADtoPave) [3] 2.3 Extraction of drill cores 1). This makes it possible starting from test interpretation to especially developed for pavement engineering was used (�igure data management up to structural analyses and evaluation of sections distributed throughout the whole section, if possible in The extraction of drill cores takes place in all de�ined structural the structural substance edit everything as a one stop. The work the right-hand wheel path. The aim is to achieve a representative processes are considerably accelerated and the usability is excellent. sample. That is essential for mathematically consideration of the variation of the material parameters and the variation of the layer thicknesses in the calculation.
2.4 Determination of the performance parameters
The determination of the performance parameters in laboratory takes place at specimen prepared from drill cores. For all in the pavement existing asphalt layers the following tests has to be carrying out.
• stiffness (bituminous mixtures – test methods for hot mix asphalt EN 12697 Part 26) with IT-CY according to the German guidelines TP Asphalt-StB, part 26) [6] Figure 1: Analysing and Design Tool for And additionally, for the asphalt base course Pavements (ADtoPave) [3]
• resistance to fatigue (bituminous mixtures – test methods In the investigated section, the following construction layers for hot mix asphalt EN 12697 Part 24) with IT-CY were found: according to the German guidelines TP Asphalt-StB, Part 24) [5] • asphalt surface course, average thickness of 4 cm
The last test is the • asphalt binder course, average thickness of 5 cm
• determination of the interlayer bond between the • asphalt base course, average thickness of 13 cm asphaltlayers on drill cores according to the German • stabilization of the sub base, average thickness of 15 cm guidelines (TP Asphalt- StB, Part 80) [9] The thickness of the construction layers was evaluated in 2.5 Evaluation of the structural substance advance by measurements by georadar and additionally by drill cores. Furthermore, the laboratory investigation shows that the For the evaluation of the structural substance two different (grading 11 mm), the asphalt binder course as a asphalt concrete procedure, the structural substance will be calculated based asphalt surface course could be identi�ied as a stone mastic asphalt procedures are possible. By using the �irst way i.e. the deterministic (grading 16mm) and the asphalt base course as a asphalt concrete on average values of all essential needed parameters. If the too (grading 32 mm). probabilistic procedure is chosen, the variability of the parameters
40 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings 3.1 Traf�ic load Table 1 shows exemplarily the material parameter of the master-curve of the tested asphalt surface course. number of daily axle transitions for heavy load of 4856 were Table 1: Parameters of the master curve of the Based on the present traf�ic census (year 2015) an average asphalt surface course expected thicknesses according to the German guidelines. determined. The found layer thicknesses in �ield appropriate the z1 z0 T0 Φ 3.2 Extraction of drill cores [N/mm²] [N/mm²] [-] [-] [°C] [-] E-∞ E+∞ The extraction of drill cores in the structural homogeneous 0 23277 -0,751602 1,998533 20 22377 section was done as a so-called section sampling. That means the drill cores are not extracted in one place of the investigated section Figure 2 shows the master curve of the asphalt surface course but uniformly distributed over the investigated section. including the measured values.
In the structural section with a length of nearly 1200 m 21 drill cores had to be extracted in general for all required laboratory tests.
In detail the following number of drill cores was used for the performed material tests (vgl. Pkt. 2.4):
• 13 drill cores for determining the resistance to fatigue
• 5 drill cores for determining the stiffness
• 3 drill cores for determining the interlayer bond
3.3 Material testing - determine the performance parameters Figure 2: Master curve of the asphalt surface course Master-curve For better understanding shows Figure 3 the absolute value of On the basis of bituminous mixtures – test methods for hot mix the complex young’s modulus only depending on the temperature asphalt EN 12697 Part 26 with IT-CY and according to the German (constant frequency of 10 HZ) of all tested asphalt materials in the guideline’s TP Asphalt-StB, Teil 26 [6] equation 1 is used as the investigated section. master-curve function. (1) with
|E*| absolute valueof the complex young’s modulus (stiffness) [MPa]
high frequencies [MPa] |E*|+∞ limit of stiffness at low temperatures and/or low frequencies [MPa] |E*|-∞ limit of stiffness at high temperatures and/or x* any value on the abscissa at the master curve, determined with the temperature-frequency-equivalence [Hz] Figure 3: Absolute value of the complex young’s , material parameters of the master-curve [-] modulus depending on temperature of all tested asphalts T0 reference temperature [°C]
Φ material Parameter [-]
41 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Resistance to fatigue 3.4 Evaluation of the structural substance using the deterministic procedure The function for the description of the fatigue of asphalt is another essential base for dimensioning und the assessment of the 3.4.1 Pavement construction structural substance. Equation 2 shows the mathematical function. In the deterministic procedure the layer thicknesses are considered as average values of all measurements. The values with based on measurements with the georadar and include the asphalt layers and the stabilization.
εel,Anf… elastic stain (initial stain) [‰] As a safety factor the thickness of the asphalt base course
Nzul… bearable load cycles must be mathematically considered as a the 10-percentile value
k, n… material parameter [-] construction. (p=0,1; α=95%). Figure 5 shows the used model of the pavement Table 2 shows the material parameters of the fatigue function.
Table2: Parameters of the fatigue function for the asphalt base course
k n
[-] [-] 8,888921 -2,676168
Figure 4 shows the function including the values of the material tests on the example of the asphalt base course. Figure 5: Model of the investigated pavement construction
3.4.2 Traf�ic load and climate conditions In rare cases detailed axle loads are known. So, it is possible on the one hand to determine theses necessary information even before the tests of the structural substance started or well-known axle load distribution are used on the other hand. In the concrete example a standard axle load distribution (Figure 6) for federal highways was used, because the investigated road is the connection
of two highways with a high percentage of heavy load traf�ic. Figure 4: Fatigue function of the asphalt base course
Interlayer bond
The investigation of the interlayer bond was carried out with the shear test according to the German guidelines (TP Asphalt-StB, Part 80) [9]. The test has to performed for all interlayer bonds, i.e. the asphalt surface course and asphalt binder course as well as asphalt binder course and asphalt base course. The test results Figure 6: Used axle load distribution [1] the calculation a full impact of the interlayer bond was assumed. show that the limits of the requirements were ful�illed, so that in
42 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Either for dimensioning as well as evaluation of the structural pavements can be used (RSO Asphalt, draft 2016) [2]. The substance, characteristic temperature pro�iles for asphalt frequencies of these temperatures are depending on climate zones. For the whole country of Germany 4 different climate zone coordinate of the position of the section can be entered directly in are de�ined. Alternatively, and very easy for the usability is, the the software ADtoPave and the climate zone is chosen automatically.
3.4.3 Material parameter Figure 8: Total asphalt layer thickness, measured with The used material parameters for the procedure are descripted georadar (blue -measured values; red - average value) in Pkt. 3.3. If it is worked only with average values, for instance with 3.4.4 Results the average value of the total thickness, the impact of thinner or bigger thicknesses will be neglected. Therefore, the variability of Figure 7 shows the result of the calculation by using the the layer thickness is modeled stochastically in order to be able to deterministic procedure with a remaining service life of the carry out a discretization with classes of thickness and associated section of nearly 15 years. The ordinate represented the state of fatigue. State of fatigue describes the ongoing process of fatigue of the asphalt base course layer. The calculation of the damage class probability. In the concrete example 5 classes were de�ined accumulation depending on time follows the well-known “miner´s (�igure 9). Class 3 represented the average value of the total layer classes below, classes 4 and 5 above the average value. rule”. If the state of fatigue reaches 100 %, it must be assumed thickness with 225 mm (�igure 10) Classes 1 and 2 representing that the base course layer isn’t able to bear the applied stresses in future. This information is essential for the decision of the kind of maintenance. Important is, that the layers which will be renewed are adjusted to the service life of the remaining asphalt base course layer.
Figure 9: Classes of layer thickness with associated probability
Figure 7: Remained service life of the asphalt base course layer until 100 % state of fatigue are reached
3.5 Evaluation of the structural substance using the probabilistic procedure
3.5.1 Pavement construction Fundamental difference by using the probabilistic procedure is the consideration of the variation of the relevant input values. thicknesses. Figure 8 shows as an example the measured total Every pavement construction subjected to �luctuations of the layer Figure 10: Model of the investigated thickness, i.e. the thickness of all three asphalt layers together. pavement construction
43 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
3.5.2 Traf�ic load and climate conditions 3.5.4 Results The number of possible combinations of the input and comparison parameters (number of virtual sub-sections in one way explained under point 3.4.2. Traf�ic load and climate conditions are considerate in the same structural homogeneous section) results from the number of classes selected in the context of the discretization. In the present 3.5.3 Material parameter example the following classes for the existing three asphalt layers Just like the layer thicknesses, material parameters are also were selected:
Master-Curve: 3 classes for each asphalt layer) values (stochastic sample) placed above and below the regression subject to �luctuations. It is recognizable that the measured stiffness function (average function) in Figure 2 (Pkt. 3.3). Fatigue function: 7 classes (asphalt base course)
Discretization is also used for stochastic description of the Layer thickness: 5 classes (thickness in total) material variation in order to be able to create classes with assigned class probabilities. Three classes were determined for the Based on this assumption 945 combinations (3 x 3 x 3 x 7 x discretization of the stiffness in the example so that consequently 5) can be determined. The decisive factor at this point is that three master-curve functions represented theses classes. Figure 11 these combinations only results from construction and material shows the master-curves in linearized form. variations. For each of these virtual subsections resulting from the
load and climate must be calculated to be able to calculate the total explained combinations, the damage of the impacts from traf�ic amount of the damage accumulation. The sum of the frequency of occurrence of all virtual subsectors with a total damage > 1 corresponds to the failure probability of the investigated sector, i.e. the structurally homogeneous section. In the result of the discussed example a failure probability of 20 % will be reached after 9 years
(�igure 13), i.e. a �ifth of the asphalt base course in the investigates after 9 years (starting from the point of analysis). section isn’t able to remain the impact of traf�ic load and climate Figure 11: Linearized master-curves for
For betterthe three understanding, de�ined classes Figure 12 shows the stiffness modulus depending on temperature on the example of the asphalt has to be done additionally for the asphalt binder layer and the surface course, based on the three class functions in �igure 11. This asphalt base course layer too.
Analogous to the consideration of the variability of the stiffness modulus, the variability of the fatigue of the asphalt base course is to be treated. The separate presentation is dispensed with at this point. Figure 13: Remained service life of the asphalt base course layer until 20 % failure probability are reached
If a lesser failure probability is chosen for the investigated section, the predictable remaining service life is consequently shortened. Figure 14 shows this fact with an assumed 10% failure probability, with a predictable remaining service life of only 5
years. The authorities can in�luence the determination of the route- speci�ically de�ined failure probability, for example with regard to probabilities between 10% and 20% depending on the road class the priority of the route or �inancial resources. Currently failure are recommended. Figure 12: Absolute value of the complex young’s modulus depending of temperature for the three de�ined classes 44 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
2. Richtlinien zur Bewertung der strukturellen Substanz des
RSO Asphalt, Entwurf. FGSV 2016. Oberbaus von Verkehrs�lächen mit Asphaltdeckschicht. 3. Analysing and Design Tool for Pavements (AD-toPave), IDAV GmbH, Schnorrstraße 70, 01069 Dres-den
4. Richtlinien für die Standardisierung des Oberbaus von
5. TechnischeVerkehrs�lächen. Prüfvorschriften RStO. FGSV für2012. Asphalt, Teil 24 Spaltzug-
Asphalt-StB, Teil 24. FGSV 2018. Figure 14: Remained service life of the asphalt base Schwellversuch – Beständigkeit gegen Ermüdung. TP course layer until 10 % failure probability are reached 6. Technische Prüfvorschriften für Asphalt, Teil 26 Spaltzug-
3.6 Conclusions StB, Teil 26. FGSV 2018. Schwellversuch – Bestimmung der Stei�igkeit. TP Asphalt- The assessment of the structural substance according to the RSO asphalt, draft 2016 is used to calculated the remaining service 7. Technische Prüfvorschriften für life of asphalt base layers. This is the basis for the decision whether 3.1.05. TP B-StB, Teil 3.1.05. FGSV 2016. existing asphalt pavement can be retained or a reconstruction Verkehrs�lächenbefestigungen – Betonbauweisen, Teil should be sought. With regard to the decision-making basis, 8. Technische Prüfvorschriften für Asphalt, Teil 27 the calculation results are more reliable when the probabilistic Probenahme. TP Asphalt-StB, Teil 27. FGSV 2016. procedure is used. Using this procedure, the remaining service life could be assessed between 5 and 9 years with a failure probability 9. Technische Prüfvorschriften für Asphalt, Teil 80 of 10% respectively of 20%.In other words, after 5 years or 9 Abscherversuch. TP Asphalt-StB, Teil 80. FGSV 2007. respectively 20% of the investigated structural homogeneous 10. Technische Prüfvorschriften für Boden und Fels im years of further impact of traf�ic load and climate in�luence, 10% section is to be regarded as failed, which is an essential statement Straßenbau. Teil E1 Prüfung auf statistischer Grundlage – for the maintenance strategy.
Stichprobenprüfpläne. TP BF-StB E 1. FGSV 1993. 3.7 References 11. 1. Richtlinien für die Dimensionierung des Oberbaus von Zusätzliche Technische Vertragsbedingungen und aus Asphalt. ZTV Asphalt-StB. FGSV 2007. Fassung 2013. Richtlinien für den Bau von Verkehrs�lächenbefestigungen FGSV 2009. Verkehrs�lächen mit Asphaltdeckschicht. RDO Asphalt.
45 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Risk in solar parks: a parametric approach of comparing AHP and TOPSIS methods
N. Ranganath1*, Debasis Sarkar2, Vinaykumar S. Mathad3, Saurav Kumar Ghosh4
1*EI Technologies, Bangalore, India 2CEPT University, Ahmedabad, India 3E I Technologies Pvt. Ltd. Bangalore, India 4HKBK College of Engineering, Bangalore, India
*Corresponding author: N. Ranganath, Chairman & amp; Managing Director, EI Technologies, Bangalore, India, Email:
Abstract Renewable energy sector projects like development and implementation of solar power plants
like any complex infrastructure projects, the solar power projects face risks and uncertainties are crucial in the present era to suf�ice the target for generation of green and clean energy. Just throughout its many phases. The risk assessment for projects remains a multi-variable problem as a
and employs two methodologies of risk analysis while comparing between the two. It has been lot depends on human expertise. The present work identi�ies the risks involved in its various phases observed that the TOPSIS approach produces more coherent interpretation than the AHP approach.
park and then subsequently compared with the AHP analysis of the same. It has been inferred that This is the �irst study where TOPSIS approach is employed for the case of risk assessment of solar for niche and isolated projects AHP is more suitable however for more general and multiple source data TOPSIS is the superior approach. The risk assessment is broken down into 5 phases and it has been observed that based on the risk indexing of those phases, the project authorities cannot afford to ignore any of the phases.
Keywords: Solar Parks; Feasibility Study; Risk Management; TOPSIS; AHP
1.0 Introduction
Complex multidisciplinary infrastructure projects suffer huge risk analysis of a complex infrastructure project like construction of risks starting from the inception of the idea to its feasibility, design, elevated corridor for metro rail operations through Expected Value development, implementation and operation [1]. If these risks are Method (EVM) which was later implemented by [2], [3, 4] carried not properly addressed by the project authorities and mitigated out risk analysis and developed risk index through Fuzzy Analytical priory by adequate mitigation measures, then the project runs the Hierarchy Process (FAHP) for an elevated corridor metro rail likelihood of collapses due to time and cost over- run. Risk analysis thereby becomes a crucial activity to be carried out by the project of risk mitigation measures are the three basic steps for carrying out project in India. Risk identi�ication, risk analysis and development authorities during the feasibility phase of the project. Risk analysis the risk management process [2]. Risk analysis can be carried out determines the severity of the risk in a quantitative manner by through various Multi Criteria Decision Making (MCDM) methods. formulating risk maps. Based on the scale of risk maps which [5] Introduced the fuzzy set theory within MCDM which was used indicate low, medium, high, very high and critical risk zones, the by many researchers working in decision making. corresponding mitigation measures can be adopted. [1] Carried out
46 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
In the risk analysis concept, identifying and assessing risk Recent trends in the construction industry indicate continued variables is an important step that should be conducted by a project use of alter- native procurement methods such as design-build, manager to get an early warning about the possible risk variable construction management, build-operate-transfer, and privatization using statistics that can occur in the project. Many techniques exist [12]. Increased use of these evolving methods produces higher in order to quantify and assess such risk variables into formulating levels of uncertainty with respect to long term performance and decision making parameters. Other approach is applying fuzzy logic portability. The uncertainties inherent in implementing new as an algorithm to capture the disguises of perceptible perceptions procurement methods necessitate investigation of enhanced combined with the Technique for Order Preference by Similarities methods of pre- project planning and analysis. This aspect is to Ideal Solution (TOPSIS) method. Furthermore the evaluation particularly true for revenue de- pendent projects such as toll tax of the risk priority number is based on fuzzy TOPSIS to the ideal on roads/highways. Enhanced risk analysis tools provide improved solution to solve multi criteria problems. information for pre-project decision making and performance outcome. One such risk analysis method is the Monte Carlo [12] In the recent years, intensive research and development for revenue dependent infrastructure projects. Mathematical has been carried out in the area of Project Risk Management analysis is limited for some studies available in the literature due (PRM) [1, 3, 4]. It is widely recognized as one of the most critical to constraints in data about the overall reliability of a system. This issues leads to shifting the domain to input set of parameters from The construction industry, perhaps more than the rest, has been procedures & capability areas in the �ield of project management. plagued by risk, resulting in poor performance with enhanced costs and time delays. Every part of project life cycle is subject to expert knowledge in the �ield. Thus, a lot of crucial parameters that are identi�ied before they are put to any mathematical modeling risks, which have to be treated adequately to stay in control of the obtained opinion about the inherent parameters. This problem project and to achieve its goals in an optimal way[6] formulated the or simulation are provided by the �ield experts or by statistically probabilistic infrastructure risk analysis model, presenting a holistic of the cases as shown by [13] leading to the use of probabilistic risk usually continues due to the lack of hard quanti�iable data in most approach for modeling the water distributions infrastructure analysis. systems dynamics. Further work of [7] presents the application part of such risk analysis model by characterizing the water system The emergence of information technology has transformed the along the parameters of function, structure, component, state, and situation from one characterized by little data to one characterized vulnerability, while keeping in view of other political, temporal and by data over-abundance [13]. Critical infrastructure systems such economic perspectives. Expected and extreme risks are evaluated as electric power distribution systems, transportation systems, water supply systems, and natural gas supply systems are important presented in a multi-objective framework. The methodological examples of problems characterized by data over-abundance. using probability, while ef�icient alternatives are generated and framework can be easily applied to other critical infrastructure There are often substantial amounts of information collected and archived about the behavior of these systems over time. Yet it can measure of any system susceptibility to threat scenarios while elements and networks. (Author?) [8] De�ines vulnerability as a demonstrating that vulnerability is a condition of the system assessment due to the long list of variables and trickier limitation be very dif�icult to effectively utilize these large data sets for risk to assigning weight age values to these parameters. One of the Assessment Model (I-VAM). Such a model requires establishing unforeseen and unpredictable parameters in the risk assessment of which can be quanti�ied using the Infrastructure Vulnerability value functions and weights to various protection parameters any infrastructure system comes from natural disasters, the impact of the system. Additionally the un- certainty in measurements and the scale of which is very unpredictable depending upon the is taken into account by suitable simulations along with expert’s kind of infrastructure in consideration. Other industrial risk and contingencies can be well designed and streamlined through a well- structured organization and management system. Sometimes, the feedback depending on the particular �ield, eventually providing a terrorist activities due to their unforeseen nature are clubbed along vulnerability density function (Ω). [9] carried out risk assessment primarily for construction the natural disasters and are sometimes considered as a separate industry and concluded that in construction industry things do not parameter in the risk management studies [14, 15]. Compared to always turn as planned and thereby detailed risk management is other infrastructure industries, construction industry is subjected must. [10] Suggested in developing methodologies which can put to greater risk due to its unique features in various project risk management into practice. Furthermore, [11] claimed that phases like planning, investigation, collection of data, feasibility, all the undertaken risk management practices focuses on project design and development, implementation and execution as well uncertainty. However, project risks are all about project cost and as operation & maintenance. Many complex mega infrastructure unscheduled uncertainties [2]. Thereby, the risk management unarguably should be focused on project uncertainty and construction of elevated and underground corridors for metro rail, projects like setting up of solar park, power projects, re�ineries, complexity management. etc. have experienced large variations in cost & scheduling leading
47 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings to enormous load on manpower, longer delays in the execution & of this study is that unlike the other models used in the literature, commissioning of these projects. the single network model can manage all the information of the real- world problem and thus it is the decision analysis model. In most of the cases, the economic viability itself ends up The strengths and weaknesses of ANP as a multi-criteria decision being questioned due to delay in project completion on account of analysis tool are also described in their work. In the further works various risks encountered during implementation stage. It is a well- of [21], the criteria for accepting or rejecting any proposals for such established fact that due to increase in project size & complexity, an investment based on risk priorities. [22] extended the research higher levels of risk & uncertainty are inevitable. Hence, a in all forms of renewable energy, wind, water and solar power in systematic process of risk analysis is imperative to classify, identify their work. Cost effectiveness studies of solar power can be found and analyze these risks, for the corresponding formulation of risk in literature [23, 24, 25]. A preliminary case study of solar parks response strategies [16]. has earlier been carried out in our earlier works showing the role of vigilance in design and construction [26]. Adding to the previous Substantial work has be carried out in risk assessment and work and understanding, an attempt is put forward in applying management of the same [17, 18]. [19] studied the relationship the known approaches of risk management on solar power between management support for risk management processes parks and commenting on the better approach to deal with multi and the reported project success extensively complimenting with criteria decision making and substantial crucial parameters. The primary objective of this work is to compare the two approach and opportunities. the identi�ication of shortcomings and possible improvement determine their merits and demerits over one other by identifying [1] argues that one needs to identify the various stages of and evaluating the risks and uncertainties associated with a projects such that, the entire work of project implementation from complex project like solar power plant installation in India. concept to commissioning can be divided appropriately in different phases such that, broad activities can be grouped under each 2.0 Methodology
The methodology is primary data research, where the data risk associated for those broad and sub activities. Same has been phase and sub activities may be de�ined which in turn portray the pertaining to risks associated with the different activities of employed in the present work where an attempt is made to explore the solar power plant has been collected from solar power the relationship between broad and sub activity risks under each plants at three locations in India namely Rajasthan, Gujarat and phases of project related solar power plant. Development of questionnaires for risk rating using Saaty Scale, probability of risk activities with respect to health, safety, environment, quality, site occurrence & impact of risk for assessment of risk severity, risk Karnataka respectively. The identi�ied risks pertained to the selection, investigation, planning, approvals, design, resources and index & risk ranking are carried out. For this, three projects located in three different parts of India have been considered. To achieve and grouped into 5 phases as following the above mentioned objectives, two research frameworks have maintenance of solar parks. The identi�ied risks were categorized 1. Feasibility Study and TOPSIS. been employed using Modi�ied Analytic Hierarchy Process (MAHP) 2. Survey, investigation, master plan & concept report As solar parks are still either rare or under development & installation, can be considered to be in the cocoon phase, not much 3. literature is available on the risk assessment or risk management Electrical, Scada & Transmission Line Detailed Design & Speci�ications - Civil, Structural, or such solar parks yet. As discussed earlier that for other infrastructure projects, risk management is studied both in detailed 4. Vendor Selection, Procurement, Construction & in theory and in application. However, these learning are not Commissioning
5. Operation & Maintenance few isolated studies here and there which are discussed later. One speci�ically applied to the risk management of solar parks except a such relevant work is by [20] who studied the Analytic Network Further details of each phase with broad categories are depicted Process (ANP) and applied the same to the selection of photovoltaic in Table-1, 2,3,4,5. (PV) solar power projects. These projects follow a long management and execution process from plant site selection to plant start- up. 2.1 Analytical Hierarchy Process (AHP) As a consequence, there are many risks of time delays and even of project stoppage. These risk and vulnerabilities are only hurdles in Analytical Hierarchy Process (AHP) is one of Multi Criteria decision making method that was originally extensively By [27] as a method to deliver a tioscales from paired comparisons. The input terms of economic aspect or ef�iciency consideration. This study order to invest based on risk minimization. The main conclusion can be obtained from actual measurement such as price, weight etc. identi�ied 50 project execution delay and/or stoppage risks in
48 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings or from subjective opinion such as satisfaction feelings and preference in a quantitative magnitude scale. The limitations of this approach are a little in consistency as inputs from human judgment is relatively constrained. The ratio scales are derived from the principal Eigen vectors and the consistency indexes derived from the principal Eigen value.
Table 1:
No Broad RisksActivities Identi�ied with underRisks Phase-1 a Letter of Intent (LOI) b Acceptance and Kick of Meeting & Finalization of the Scope and Deliverables. c Risks in Site location d Reconnaissance Survey of Site e Collection of Data f Inception Report Preparation (IR) & Submission g Review and Approval IR h Preparation & Submission of Draft Feasibility Report (DFR) i Presentation and Discussion j Approval of DFR k Submission of Final DFR
Table 2:
No Broad RisksActivities Identi�ied with under Risks Phase-2 a
b ResourceDelay of Site Mobilization Land Handover & Establishing camp & site of�ice. c Topographical Survey d Land Acquisition Risks e Environmental Risks f Resettlement and Rehabilitation Risks g Geo-tech Investigations h Data Analysis i Master Plan & Concept Report j Approval of Master Plan & Concept Report
Table 3:
No Broad RisksActivities Identi�ied with Risks under Phase-3 a Revision in Master Plan b Risk in DPR Preparation c Design of Civil Works d Design of Structural Works e Design of Electrical, SCADA& Transmission Line Works f Preparation & Submission of Draft Detailed Project Report (DDPR) including Tender Documents g Approval of DDPR& Tender documents h Submission of Final DPR & Tender documents
49 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Table 4:
Broad Risks Identi�ied under Phase-4 No Activities with Risks a Invitation of Tender & Award of Work b Letter of Intent (LOI) to Contractor c Acceptance and Kick of Meeting & Finalization of the Scope d Financial Closure Risks e Permit and Approval Risks f Civil Works Construction & Quality g Mechanical & Electrical Works & Quality h Safety
Table 5:
Broad Risks Identi�ied under Phase-5 No Activities with Risks a Operation b Maintenance
The data analysis of the quantitative output of the qualitative In order to estimate the risk index and risk ranking, normalized attribute survey for each attribute of quality, risk assessment can weights have been estimated based on the total weights calculated be obtained using MAHP data analysis tool which is a multi-criteria for each phase. These normalized weights have been multiplied decision making tool used to obtain ranks and outputs. Initially, a with risk severity to estimate the risk index which side noted as questionnaire is formulated to obtain the responses per tainting to Risk Index=Risk Severity X Normalized Weights (Wn). by industry experts of a sample space of 200.These values range 2.2 TOPSIS “Probability of occurrence of risk” and “Impact” which is �illed up from 0to1 where 0 indicates nil probability of occurrence of a risk and impact while 1 indicates very high probability of occurrence Making (MCDM) technique termed as Fuzzy TOPSIS. TOP SIS is of a risk and impact. For computational simplicity, the risk rating The identi�ied risks we reanalyzed with a Multi Criteria Decision a multi-criteria decision analysis method, which was originally values obtained from questionnaire survey have been converted developed by [28] with further developments by [29]. TOPS Isis into “Saaty Scale” (1to5) where1 denotes least importance and based on the concept that the chosen alternative should have 5 represent highest importance. Additionally, a level of risk non- the shortest geo metric distance from the Positive Ideal Solution singular matrix is created for each item of the chosen subgroup (PIS) and the longest geo metric distance from the Negative Ideal (elements of row1 are divided by weights of respective column Solution (NIS). It is a method of compensatory aggregation that to that of row and soon). Probability weight based non-singular compares a set of alternatives by identify in weights for each matrix is created for each item of the chosen subgroup. This process criterion. As the parameters or criteria are often of in congruous is repeated for all the three solar park sunder study in this case with dimensions in multi-criteria problems it may create problems the Saaty scales for each of the phases in terms of broad activities in evaluation. So, to avoid this problem a need o fuzzy system is and sub-activities separately. Another constraint to this process is necessary. Using fuzzy numbers in TOPSIS for criteria analysis that it cannot differentiate between the better solar parks or can the evaluation becomes simpler. Hence, Fuzzy TOPSIS is simple, make any quantitative assertion among the case studies. The level realistic form of modeling and compensatory method which of risk weights and probability weights are normalized. Normalized jn=1, …… 1 includes or excludes alternative solutions based on hard cut-off. value= { II ia = 1 a } , where n is the number of it emsunder the n It is important to note that for all the development phases of each chosen subgroup. solar parks the Saaty data used in the AHP is the input to the TOPSIS method where it is converted to the corresponding fuzzy numbers equation of EVM methodology: Risk Severity=Risk likelihood or (whereSaatynumber1correspondstofuzzy (1,1,3), 2 corresponds The severity of the identi�ication risks can be computed by the probability of occurrence X Impact which lies from 0-1 demarcated to (1,3,5), 3 corresponds to (3,5,7), 4c corresponds to (5,7,9) and 5 corresponds to (7,7,9) respectively). In this approach the saaty very high (0.31-0.5), critical (0.51-0.7) and very critical (0.71-1). numbers are converted into fuzzy number sets for the same by categories of �low (0-0.1), medium (0.11-0.2), high (0.21-0.3),
50 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
parameters for different solar park. Then the mixed data set x ij is c) Project in Karnataka: created to combine the inputs from all sources of Rajasthan, Gujarat and Karnataka, where Highest risk is observed in Phase-2i.e. SURVEY, INVESTIGATION, MASTERPLAN & CONCEPT REPORT Stage of the project based on
Sub Activities and Phase 1 i.e. FEASIBILITY STUDY based on Broad
aaa−−− Activities. jjj The matrix x ij is further converted to rij = ,, cba ij ij ij 3.2 TOPSIS results − where aa j = min ( ij ) as risk is only a cost criteria and not The analysis and interpretation of data obtained using the TOPSIS method is tabulated inTable-15 where the higher value of C Moreover the weight age values (w ) are obtained from the experts a bene�icial one thus analysis is preferredj using the lower values. Cede notes higher risk factors and its thereby rankings in terms of just like the saaty value and further converted into fuzzy numbers. risk, higher number denoting higher risk. Then, the matrix V ij = rw ij * j is obtained. Henceforth, It can be seen that if the analysis is performed based on broader are evaluated activities then phase-3 is the highest in terms of risk. Similarly, obtained. These new variables help in obtaining the distance inference can also be drawn from looking at the analysis is done parameters which are denoted as with sub-activities where the data shows that phase-5 has the maximum risk. This is in accordance that phase-5 deals with sub- activities with bigger natural hazards and uncertainties. How- ever, if the lowest risk is observed that conclusion remains the same whether broad activities or sub-activities are looked into Based on d − CC = Finally, . The the highercloseness the coef�icientCCi value higher is calculated the ranking. using broad activities phase-1 is at the lowest most risk as it involves post i dd* + − project maintenance which grebes with the general understanding. 3.0 Results & Discussions With respect to sub-activities as well, Phase-1 shows the least most risk. In general, phase-3 shows relatively higher amount of 3.1 AHP results risk from both the broad activities and sub-activities analysis. This contradicts with the AHP results were in two of the solar parks The outcome of the analysis towards assessment of risk index phase-2 was found to have greatest risk rankings. However in for each project as obtained from the analysis as explained in the TOPSIS analysis, phase-2 stays third in terms of both broad and sub- activities showing medium level of risk involved. The advantage of The gist of conclusions can be summarized as methodology section are �inally tabulated in Table- 11, 12, 13, 14. this analysis is that it takes into account all the solar park locations at once and provides a more generic and reliable understanding of a) Project in Rajasthan: the risk on the whole. Where as in AHP the solar parks can only be Highest risk is observed in Phase-2 i.e. SURVEY, INVESTIGATION, studied separately. In other words there is no way to inculcate the MASTER PLAN & CONCEPT REPORT Stage of the project on both data from Rajasthan Gujarat and Karnataka all in one go for the AHP Broad Activities as well as Sub Activities. analysis. The TOPSIS approach combines the fuzzy numbers from
b) Project in Gujarat: all solar parks in the �irst step in formulating the X ij and thereby variables of all solar parks into a single chart. A sample calculation generalizes the parametric fuzzy numbers o of all the identi�ied Highest risk is observed inPhase-4 i.e. VENDOR SELECTION, of Phase-5 is shown in Table-16. PROCUREMENT, CONSTRUCTION AND COMMISSIONING Stage of the projection both Broad Activities as well as Sub Activities. Table 6:
No ActivitieswithRisks Sub Activity Risks Identi�ied underPhase-1 1 Delay in Issue of LOI 2 Wrong Details of Contract 3 Delay in responding to Wrong details by Client 4 Delay in Acceptance of LOI 5 Delay in conducting Kick of Meeting 6 Gaps in scope of work 7 Improper objectives Scope & Deliverables
8 Proximity to International border �inalisation 9 Proximity to wild life sanctuary 51 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
No ActivitieswithRisks 10 Presence of forest land 11 Proximity to eco sensitive zone 12 Proximity to Historical monuments,Place of worship etc. 13 Presence of sensitive lands within the project boundary 14 Highly undulating androcky terrain. 15 Presence of Built-up Close to Project 16 Access to Site 17 Ground Water Table 18 Impact on Environment 19 Social Impact 20 Availability of Land 21 Permission from Government 22 Presence of low laying area. 23 Identi tion of Different Site for Reconnaissance
24 Wrongly�ica of Site Boundary & Orientation 25 Missing ofIdenti�ication Key Data during Reconnaissance survey 26 Improper Data Collection 27 Inadequate Data Collection 28 Misinterpretation the Scope of Work 29 Methodology
30 De�ining oft Unrealistic Time Allocation Approach for Investigation& & Design 31 Insuf�icienDelay in Submission of IR 32 Review by non-technical professional 33 Delay in review & forwarding the observations 34 Delay in approval of IR 35 Improper Approach & Methodology for Feasibility Report 36 t Survey & Investigation
37 Insuf�icienMistakes in Conducting Survey & investigations 38 Hydraulic andhydrological Investigations 39 Recommendation of Foundation Type 40 Poor Interpretation of Data 41 Wrong Planning of Master Plan 42 Presence of Utilities 43 Raw Material Sources 44 Preliminary Design 45 Drawings & Documentation 46 Mistake in Quantity Calculations 47 Adopting Wrong Schedule of Rates for Estimation 48 Delay in Preparation of Draft Feasibility Report 49 Delay in Submission of Draft Feasibility Report 50 Presenting Wrong Details about Project 51 Discussions of un-related points during presentation 52 Authenticity of Clients Observations & Incorporation in Report 53 Review by non-technical professional 54 Delay in review & forwarding the observations 55 Delay in approval of DFR 56 Delay in Receiving Comments/ Observation of Draft DFR 57 Delay in Attending the Comments/ Observation of Draft DFR 58 Delay in Submission of Final Feasibility Report
52 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Table 7:
No Activities Sub with activity Risks Risks Identi�ied under Phase-2 1 Access improper
2 Delay into Marking project of�iceof site is 3
4 DelayLack of in Conducive construction environmen of projectt of�ice 5 Lack of basic amenities and infrastructurein the of�ice 6 Delay due to all permits and procedures are in place before any work commence 7 establishment
8 Delay in setupSite Land of project hando vsiteer of�ice, Lay down area and site 9 Delay in Taking over of the site 10 Delay in Survey &Investigation 11 Delay in Detailed Project Report (DPR) 12 Delay in Construction 13 Joint boundary demarcation 14 Delay due to Wrong of Site
15 Delay due to Site HandingIdenti�ication over for w ork 16 Mistake in Establishing Horizontal &vertical Control points 17 Deployment surveyors
18 Deployment of unquali�iedpoorly calibrated equipments 19 Not connecting to national grid such(GTS) and Mean Sea Level 20 Wrong project boundary Iden
21 Omission of major topographicalti�ication details 22 Elevation of land is not properly done through survey or equipments 23 Political interference 24 Faulty Revenue Survey 25 rehabilitation schemes
26 DelayPublic in interference �inalizing temporary for changing the Site 27 Interference of environmental activists 28 Delay due to inter department a issues 29 Delay in construction of diversion roads for existing
30 Cost of Compensation traf�ic 31 Problems with the physical possession of land 32 Deforestation 33 Reduction in Intensity of Rainfall 34 Ecological Imbalance 35 Increase in Surrounding Area temperature 36 Resettlement site not accepted by affected parties 37 Resettlement site very costly 38 Litigation by affected parties or Litigation &R
39 Resistance and agitation by political partiesin the Site Identi�ied for R 40 Delay in Final is action of Site and Locations of Investigations 41 Delay in Deployment of Required Machineries 42 Deployment Investigation
43 Improp of unquali�ied Personnelt Inforv estigation 44 Collectioner/Inadequate/Insuf�icien of sample sand testing 45 Poor interpretation of data 46 In adequate foundation design recommendations 47 Missing of Soil Resistivity Data 48 Poor assessment of catchment
49 t Hydrological Reportarea and historical �loods De�icien 53 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
No Activities with Risks 50 Computation of Finished Grade Level for the plant 51 Wrong QA& QC Report 52 Finalization of Route for Transmission Lines 53 Processing of the data and preparation of base maps in different layers. 54 Establishment of the documentation 55 Preparation of Engineering documents in line with project requirement 56 Delay in Finalization of Master Plan &Concepts 57 Lack of Involvement of Skilled Professional 58 Misunderstanding of Data Analysis 59 Preparation & Submission of Master Plan & Concept Report for Approval 60 Presenting Wrong Details about Project 61 Discussions of un-related points during presentation 62 Authenticity of Clients Observations &on Master Plan & Concept Report 63 Review by non-technical professional 64 Delay in review &forwarding the observations 65 Delay in approval of Master Plan & Concept Report
Table 8:
Sub activity Risks identi�ied underPhase-3 No Activities with Risks 1 Minor Level in Master Plan 2 Medium Level in Master Plan Modi�ication 3 Large Level in Master Plan Modi�ication 4 Delay in Finalization due to extent of Revision Modi�ication 5 Delay in approval of Revised Master Plan 6 Wrongly of Works 7 Lack of Coordination among different teams identi�ication 8 Inadequate data &information 9 Un economical Design 10 Defective Design 11 In complete Detailing 12 Works 13 Improper Design of Site Leveling &Grading Plan Missing of Design & Speci�ications for 14 Identi tion of Type of Fencing/ Compound 15 Discarding importance of Roads, Drainage &Cross Drainage Structures �ica 16 Faulty Design of Structure Foundation for the Module Mounting 17 Location &Size of Control room 18 Location &Size of Security/Guardroom 19 Source & Raw water storage including distribution 20 Design of Module Mounting structure 21 Design of Control Room 22 Design of Maintenance Staff Accommodation 23 Design of Security Cabins 24 Design of Main entrance Gate 25 Array layout including optimization 26 Cable Trenches
54 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
No Activities with Risks 27 Switch Yard 28 Ear thing Layout 29 Overall SLD 30 HV System SLD 31 Overall PV array layout 32 Area power Ear thing &Grounding layout 33 SCADASLD 34 Substation 35 Auxiliary power 36 Transmission line 37 Site Lighting 38 Building Lighting 39 Lightening arrestor 40 Improper Approach &Methodology 41 Improper Use of Survey &Investigation Data 42 Delay in submission of drawings by detailed design consultant Civil Works 43 Delay in submission of drawings by detailed design consultant Structure Works 44 Delay in submission of drawings by detailed design consultant Electrical Works 45 Adopting Wrong Schedule of Rates for Estimation 46 Lack of accuracy in internal detailed estimate 47 Drawings 48 Short comings in internal detailed estimate/provisions De�iciency in 49 Delay in Preparation of DDPR &Tender documents 50 Delay in Submission of DDPR & Tender documents 51 Review by non-technical professional 52 Delay in review &forwarding the observations 53 Delay in approval of DDPR & Tender documents 54 Delay in Receiving Comments/Observation of Draft DPR& Tender documents 55 Delay in Attending the Comments/Observation of Draft DPR &Tender documents 56 Delay in Submission of Final Detailed Project Report &Tender documents
Table 9:
No Activities with Risks Sub activity Risks Identi�ied underPhase-4 1 Delay in preparation and approval of tender document 2 Two packet system (Technical and evaluation)is not implemented 3 Delay in issuing NIT(Notice Inviting Tender) �inancial 4 Delay in Pre-Bid Meeting 5 Delay in Response to the Queries of Bidders 6 Postponement of Tender Submission Date 7 Variations by the client 8 Improper evaluation of Tender Documents of Bidders 9 Delay in Award of Contract to Successful Bidder 10 Delay in Issue of LOI to Contractor 11 Wrong Details of Contract 12 Delay in responding to Wrong details by Client
55 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
No Activities with Risks 13 Delay in Acceptance of LOI by Contractor 14 Delay in conducting Kick of Meeting 15 Improper objectives Scope & Deliverables 16 Delay in mobilization of resources by contractor �inalization 17 Project not bankable 18 Lenders not comfortable with project viability 19 Adverse investment climate 20 Delay in contractual clearances 21 Delay in projects approvals 22 Delay in clearance from environment a land forest departments speci�ic orders and 23 Delay in the approval of relocation of major utilities (telecom cables, electrical cables, storm water drains, sewer lines). 24 Un suitable construction programmed planning (e.g. Sequence of activities is not properly planned)affecting workings chem. and quality of work. 25 Delay in Labor induction by doctor and safety officer. 26 Delay inperforms100%pre –checks and pre-inspection before the GEC do the official checks and inspections. 27 Delay in submission of GFC drawingsby contractor. 28 Delay in granting approval of drawings. 29 Drawing bullet in system is not implemented onsite for drawing progress/Implementation tracking. 30 Longer Lead for Constriction Materials. 31 Delay in Supply of Materials from Vendors 32 Increase in Cost of Materials(Steel, Cement) 33 Risks of minor/major accidents during Work 34 In effective control and management 35 Delay in Start of Construction Activity 36 Defect in Level Carrying for Site Work 37 Defects in Foundations for Module Mounting structure 38 Defective works in Other Civil Works 39 Improper Drainage Facility 40 In adequate program scheduling 41 Variation of construction programs 42 Lack of coordination between project participants 43 Incomplete approval and other documents 44 Poor construction plan 45 t experience and skill in construction works 46 Unstable supply of critical construction materials Insuf�icien 47 List of Approved materials/brands and vendors is not prepared 48 Defects in Module Mounting structure 49 Improper Erection/Mounting of modules 50 Defect in Area Power Ear thing & Grounding Layout 51 Defect in Cables &Trenches 52 Defects in Overall SLD &HV System SLD 53 Defective Switch Yard 54 Delay in Implementation of SCADA
56 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
No Activities with Risks 55 Substation 56 Auxiliary power 57 Transmission line 58 Yard Lighting 59 Building Lighting 60 Lightening arrestor 61 Main entrance Gate 62 Security/Guardroom 63 Raw water storage including distribution and connection 64 String extension cabling 65 Module Connector 66 Combiner Box 67 ICB to inverter cabling 68 PCU 69 Data logger along with PC 70 Weather Stn-Pyrano, Anemo & Temp sensor 71 Earthing System/Lighting System 72 Documentation, Department approvals, Statutory clearance 73 Testing &Pre-commissioning 74 SOP & tTraining 75 Safety of Workers during Construction Staf�ing, 76 Safety of Machineries 77 Safety of Plant after Construction
Table 10:
Sub activity Risks Identi�ied underPhase-5 No Activities with Risks Reduction in Power Generation due to Variation in Solar 1 Energy 2 Defect in the Solar Panels 3 High Rainfall 4 High Wind Causing Dust cover on Panels 5 Fire Hazards 6 Robbery of Equipment 7 Unskilled Operational Staff 8 Delay in Supply of Materials for Maintenance 9 Poor Maintenance by Operating Staff 10 Non Availability of Spare parts 11 Scarcity of Water 12 Delay in attending the break-down in operation
57 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Table 11: Risk Severity of Broad Activities Risk Factors Quality Parameters (EVM Methodology)
Project in Rajasthan Project in Gujarat Project in Karnataka Severity Severity Severity Severity Severity Severity No Risk Description of Task Risk (Qualitative) Risk (Qualitative) Risk (Qualitative)
PHASE-1 :FEASIBILITY Very 1 0.39 Very High 0.25 High 0.39 STUDY High
PHASE-2 : SURVEY, Very 2 INVESTIGATION, MASTER PLAN&CON- 0.56 Critical 0.30 High 0.33 CEPT REPORT High
PHASE-3 : DETAILED DESIGN AND SPECIFICATIONS -CIVIL, Very 3 0.30 High 0.39 0.30 High STRUCTURAL, ELECTRICAL, SCADAAND High TRANSMISSIONLINE
PHASE-4 : VENDOR Very 4 SELECTION, PROCUREMENT,CON- 0.33 Very High 0.42 0.23 High STRUCTION AND COMMISSIONING High
PHASE-5 : OPERATION 5 &MAINTENANCE OF SOLAR PLANTS 0.10 Low 0.09 Low 0.07 Low
Table 12: Risk Severity of Sub Activities Risk Factors Quality Parameters (EVM Methodology)
No Risk Description of Task Project in Rajasthan Project in Gujarat Project in Karnataka
Severity Severity Severity Severity Severity Severity Risk (Qualitative) Risk (Qualitative) Risk (Qualitative)
1 PHASE-1 :FEASIBILITY Very STUDY 0.39 Very High 0.25 High 0.39 High
2 PHASE-2 : SURVEY, Very INVESTIGATION, MASTER PLAN&CON- 0.56 Critical 0.30 High 0.33 CEPT REPORT High
3 PHASE-3 : DETAILED DESIGN AND SPECIFICATIONS -CIVIL, Very STRUCTURAL, ELECTRICAL, SCADAAND 0.30 High 0.39 0.30 High TRANSMISSIONLINE High
4 PHASE-4 : VENDOR Very SELECTION, PROCUREMENT,CON- 0.33 Very High 0.42 0.23 High STRUCTION AND COMMISSIONING High
5 PHASE-5 : OPERATION &MAINTENANCE OF SOLAR PLANTS 0.10 Low 0.09 Low 0.07 Low
58 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Table 13: Final Risk Index for factors Associated with Broad Activities Risk Quality Parameters
Project in Rajasthan Project in Gujarat Project in Karnataka
No Risk Description of Task Final Final Final Risk Risk Risk Rank Rank Rank Ranking Ranking Ranking Index Index Index PHASE-1 :FEASIBILITY 1 STUDY 0.108 2 0.070 4 0.105 1
PHASE-2 : SURVEY, 2 INVESTIGATION, MASTER 0.1531 1 0.0826 2 0.0935 2 PLAN&CONCEPT REPORT
PHASE-3 : DETAILED DESIGN AND SPECIFICATIONS 3 -CIVIL, STRUCTURAL, ELEC- 0.060 4 0.077 3 0.059 3 TRICAL, SCADAAND TRANS- MISSIONLINE
PHASE-4 : VENDOR
4 SELECTION, PROCUREMENT,- 0.0663 3 0.0834 1 0.0464 4 CONSTRUCTION AND COM- MISSIONING PHASE-5 : OPERATION 5 &MAINTENANCE OF SOLAR 0.005 5 0.004 5 0.003 5 PLANTS
Table 14: Final Risk Index for factors Associated with Sub-Activities Risk Quality Parameters
Project in Rajasthan Project in Gujarat Project in Karnataka
Final Final No Risk Description of Task Final Risk Risk Risk Rank Rank Rank Ranking Ranking Ranking Index Index Index 1 PHASE-1 :FEASIBILITY 0.084 3 0.054 4 0.086 2 STUDY
2 PHASE-2 : SURVEY, INVESTIGATION, MASTER 0.138 1 0.074 3 0.088 1 PLAN&CONCEPT REPORT 3 PHASE-3 : DETAILED DESIGN AND SPECIFICATIONS -CIV- 0.063 4 0.080 2 0.060 4 IL, STRUCTURAL, ELECTRICAL, SCADAAND TRANSMISSIONLINE
4 PHASE-4 : VENDOR SELECTION, PROCUREMENT,CON- 0.093 2 0.121 1 0.061 3 STRUCTION AND COMMISSIONING
5 PHASE-5 : OPERATION &MAINTENANCE OF SOLAR PLANTS 0.004 5 0.004 5 0.003 5
59 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings Table 15: FinalRiskIndexforRiskQualityParametersforvariousphasesusingTOPSIS method (decimal values rounded off)
CCi based on Ranking CCi based on Ranking No Phase no broad activities index Sub activities index
1 PHASE-1 : FEASIBILITY STUDY 0.099 5 0.16 5
2 PHASE-2 : SURVEY, INVESTIGATION, MASTER PLAN & CONCEPT REPORT 0.18 3 0.20 3
3 PHASE-3 : DETAILED DESIGN AND SPECIFICATIONS - CIVIL, STRUCTURAL, ELECTRICAL, SCADA AND 0.29 1 0.23 2 TRANSMISSION LINE
4 PHASE-4 : VENDOR SELECTION, PROCUREMENT, CON- STRUCTION AND COMMISSIONING 0.23 2 0.18 4
5 PHASE-5 : OPERATION & MAINTENANCE OF SOLAR PLANTS 0.14 4 0.42 1
Table16: Sample TOPSIS calculation forphase-5 (decimal values rounded off)
Activities d+ d− No Rajasthan Gujarat Karnataka Xij Rij Wj Vij Cci with risk (FPIS) (FNIS)
a Operation 5,7,9 5,7,9 3,5,7 3 6.33 9 0.11 0.16 0.33 1 3 5 0.11 0.47 1.67 3.34 0.95 0.22
1 Reduction in Power Generation 7,7,9 3,5,7 3,5,7 3 5.67 9 0.11 0.18 0.33 1 3 5 0.11 0.53 1.67 3.33 0.96 0.22 due to Variation in Solar Energy
2 Defect in the 7,7,9 7,7,9 7,7,9 7 7.00 9 0.11 0.14 0.14 1 3 5 0.11 0.43 0.71 4.29 0.00 0.00 Solar Panels
3 High Rainfall 3,5,7 3,5,7 3,5,7 3 5.00 7 0.14 0.20 0.33 1 3 5 0.14 0.60 1.67 3.33 0.97 0.23
4 High Wind Causing Dust 3,5,7 3,5,7 3,5,7 3 5.00 7 0.14 0.20 0.33 1 3 5 0.14 0.60 1.67 3.33 0.97 0.23 cover on Panels
5 Fire Hazards 3,5,7 7,7,9 1,3,5 1 5.00 9 0.11 0.20 1.00 1 3 5 0.11 0.60 5.00 0.00 4.29 1.00
6 Robbery 5,7,9 7,7,9 1,3,5 1 5.67 9 0.11 0.18 1.00 1 3 5 0.11 0.53 5.00 0.07 4.29 0.98 of Equipment
7 Unskilled Operational 5,7,9 5,7,9 5,7,9 5 7.00 9 0.11 0.14 0.20 1 3 5 0.11 0.43 1.00 4.00 0.29 0.07 Staff
8 Delay in Supply
of Materials 3,5,7 5,7,9 1,3,5 1 5.00 9 0.11 0.20 1.00 1 3 5 0.11 0.60 5.00 0.00 4.29 1.00 for
Maintenance
b Maintenance 5,7,9 5,7,9 5,7,9 5 7.00 9 0.11 0.14 0.2 1 3 5 0.11 0.43 1.00 4.00 0.29 0.07
9 Poor Maintenance by 7,7,9 7,7,9 3,5,7 3 6.33 9 0.11 0.16 0.33 1 3 5 0.11 0.47 1.67 3.34 0.95 0.22 Operating Staff
10 Non Availability of 5,7,9 3,5,7 5,7,9 3 6.33 9 0.11 0.16 0.33 1 3 5 0.11 0.47 1.67 3.34 0.95 0.22 Spare parts
11 Scarcity of 5,7,9 3,5,7 7,7,9 3 6.33 9 0.11 0.16 0.33 1 3 5 0.11 0.47 1.67 3.34 0.95 0.22 Water
12 Delay in attending the 5,7,9 5,7,9 1,3,5 1 5.67 9 0.11 0.18 1.00 1 3 5 0.11 0.53 5.00 0.07 4.29 0.98 breakdown in operation
A+ 0.11 0.60 5.00
A− 0.11 0.43 0.71
60 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings 4.0 Conclusions 4. Debasis Sarkar, Manvinder Singh. Risk analysis by integrated fuzzy expected value method and fuzzy After careful scrutiny of the results from AHP and TOPSIS failure mode and effect analysis for an elevated metro analysis the following conclusions are drawn. TOPSIS has substantial rail project of Ahmedabad, India. International Journal of advantages over the conventional AHP process in terms that it Construction Management. 2020;1–12. can evaluate the data using fuzzy numbers from various decision makers or sources. In this case, TOPSIS approach combines the 5. input of the solar parks from Rajasthan, Gujarat and Karnataka 1965;8(3):338–353. Lot�i A Zadeh. Fuzzy sets. Information and control. and combines them with the same activities and sub-activities 6. Barry C Ezell, John V Farr, Ian Wiese. Infrastructure and provides an ensemble interpretation of the parameters. The risk analysis model. Journal of infrastructure systems. results of maximum and minimum risk phase are more coherent 2000;6(3):114–117. in TOPSIS than in AHP. AHP concludes Phase-2 or Phase-4 as the highest risk depending upon the solar park. This in coherency is 7. Barry C Ezell, John V Farr, Ian Wiese. Infrastructure risk not well appreciated where the quality of results lie on external analysis of municipal water distribution system. Journal factors. The highest risk phase should be independent of the geo of Infrastructure Systems. 2000;6(3):118–122. graphical location as the parameters in the study are same for any solar park. However, TOPSIS clearly shows both the phase2 and 4 8. Barry Charles Ezell. Infrastructure vulnerability to be of medium risk. It is very evident from the comparison and assessment model (I-VAM). Risk Analysis: An International Journal. 2007;27(3):571–583. the analysis that TOPSIS is a more re�ined approach in such study 9. Osama Ahmed Jannadi, Salman Almishari. Risk assessment of various solar power parks using the same identi�ied parameters. Furthermore, AHP is limited to the study of each solar park in construction. Journal of construction engineering and separately and there exist no way to interpret one with respect to management. 2003;129(5):492–500. another. Asset can be seen the results of AHP of each solar park are shown separately and the most critical case varies case to case 10. Ray C Williams, Julie A Walker, Audrey J Dorofee. which may not be the true representation of the actual problem Putting risk management into practice. IEEE software. under consideration. Moreover, for standalone projects or niche 1997;14(3):75–82. markets of study AHP is better suited in the abs hence of other 11. Stephen Ward, Chris Chapman. Transforming project risk management into project uncertainty management. parameter across the board. related projects that can provide the same range of identi�iable International journal of project management. Phase-3 shows the maximum risk in terms of both the broad 2003;21(2):97–105. and sub activities for TOPSIS approach. However the lowest risks 12. Anthony DSonger, James Diekmann, Roger S Pecsok. belong to Phase-1 for both the broad and sub-activities. This can be Risk analysis for revenue dependent infrastructure projects. Construction Management & Economics. phases have the maximum amount of uncertainties. The justi�ied as the execution phase and the operation & maintenance 1997;15(4):377–382. comparison between the two approaches how that they different their conclusions by a substantial margin. 13. Seth D Guikema. Natural disaster risk analysis for critical References infrastructure systems: An approach based on statistical 1. Debasis Sarkar, Goutam Dutta. A framework of project risk learning theory. Reliability Engineering & System Safety. management for the underground corridor construction 2009;94(4):855–860. of metro rail. International Journal of Construction Project 14. George E Apostolakis, Douglas M Lemon. A screening Management. 2011;4(1):21–38.
infrastructure vulnerabilities due to terrorism. Risk 2. John M Nicholas. Project management for business and methodology for the identi�ication and ranking of technology: Principles and practice. PhD thesis, Univerza Analysis: An International Journal. 2005;25(2):361-376. v Mariboru, Ekonomsko-poslovnafakulteta. 2001. 15. Chenyang Lian, Yacov YHaimes. Managing the risk of 3. Debasis Sarkar, Manvinder Singh. Development of risk terrorism to interdependent infrastructure systems index for mass rapid transit system project in western through the Dynamic Inoperability Input-Output Model. India through application of fuzzy analytical hierarchy Systems Engineering. 2006;9(3):241–258. process (FAHP). International Journal of Construction 16. Rawshan Ara Begum, Md Sujahangir Kabir Sarkar, Abdul Management. 2018;1–12. Hamid Jaafar, Joy Jacqueline Pereira. Toward conceptual 61 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings frame- works for linking disaster risk reduction and areas of infrastructure, and materials. Energy policy. climate change adaptation. International Journal of 2011;39(3):1154–1169. Disaster Risk Reduction. 2014;10:362–373. 23. C-J Winter, Rudolf L Sizmann, Lorin L Vant-Hull. Solar 17. power plants: fundamentals, technology, systems, and Critique. Risk Management and Insurance Review. economics. Springer Science & Business Media. 2012. Georges Dionne. Risk Management: History, De�inition, 2013;16(2):147–166. 24. K Nithyanandam, R Pitchumani. Cost and performance 18. Alfredo Federico Serpella, Ximena Ferrada, Rodolfo analysis of concentrating solar power systems with Howard, Larissa Rubio. Risk management in construction integrated latent thermal energy storage. Energy. projects: a knowledge-based approach. Procedia-Social 2014;64:793–810. and Behavioral Sciences. 2014;119(2014):653–662. 25. R Dominguez, L Baringo, AJ Conejo. Optimal offering 19. strategy for a concentrating solar power plant. Applied Project risk management practices and their association Energy. 2012;98:316–325. Robert James Voetsch, Denis F Ciof�i, Frank T Anbari. with reported project success. In Proceedings of 6th IRNOP Project Research Conference, Turku, Finland. 26. N Ranganath, Debasis Sarkar, Surendra Singh Kachuwaha, Citeseer. 2004;680–697. Vinaykumar S Mathad, Saurav Kumar Ghosh. Role of professional vigilance in design and construction a case 20. P Aragon´es-Beltran, F Chaparro-Gonz´alez, JP Pastor- study of solar projects. In Frontiers in Geotechnical Engineering. Springer. 2019;441–453. the selection of photovoltaic solar power plant investment Ferrando, F Rodr´ıguez-Pozo. An ANP-based approach for projects. Renewable and sustainable energy reviews. 27. Thomas L Saaty. Fundamentals of decision making and prioritytheory with the analytic hierarchy process. RWS 2010;14(1):249–264. publications. 2000;6:15-35. 21. Pablo Aragon´es-Beltran, Fidel Chaparro-Gonz´alez, 28. Yunfei Li, T Cheng, SY Chen, YQ Zhao, CL Hwang, K Yoon, Juan-Pascual Pastor-Ferrando, Andrea Pla-Rubio. An KS Park, SH Kim, SH Kim, SH Choi, et al. Priority method AHP (analytic hierarchy process)/ANP (analytic network for a kind of multi-attribute decision making problems. process)-based multi-criteria decision approach for Journal of Applied Sciences. 1987;13(13):87–89. the selection of solar-thermal power plant investment projects. Energy. 2014;66:222–238. 29. Ching-Lai Hwang, Young-Jou Lai, and Ting-Yun Liu. A new approach for multiple objective decision making. 22. Mark ZJacobson, Mark ADelucchi. Providing all Computers & operations research. 1993;20(8):889–899. global energy with wind, water, and solar power, part i: Technologies, energy resources, quantities and
62 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Structural Behaviour of Reinforced Self Compacting Concrete Incorporating Alcco�ine and Fly ash
C. Sashidhar1*, J. Guru Jawahar2, Bode Venkata Kavyateja3
1Professor, Department of Civil Engineering, Jawaharlal Nehru Technological University, Anantapuramu, Andhra Pradesh, India 2Professor, Department of Civil Engineering, Annamacharya Institute of Technology and Sciences, Tirupati, India 3Research Scholar, Department of Civil Engineering, Jawaharlal Nehru Technological University, Anantapuramu, Andhra Pradesh, India
*Corresponding author: Prof. C. Sashidhar, Department of Civil Engineering, Jawaharlal Nehru Technological University, Anantapuramu, Andhra Pradesh, India, Email:
Abstract Background: The continuous demand for raw materials in the production of concrete needs cost-effective and good quality alternative cementitious materials such as Metakaolin (MK), Silica fume (SF) and Fly ash (FA) are substituting to ordinary Portland cement. Replacement of these raw materials is an added advantage to reducing carbon dioxide emissions and protecting
cementitious material from the steel industry as a partial replacement of cement. the depleting natural resources. Alcco�ine is a new generation ultra-�ine supplementary Findings: The present paper focuses on the structural behaviour of reinforced self-
compacting concrete (RSCC) beams under two-point loading incorporating alcco�ine (AL) and ash on the structural behaviour of different concrete mixes (NC, SCC0, SCC5, SCC10 and SCC15). �ly ash (FA). A total of �ive beams were cast and tested for evaluating the effect of alcco�ine and �ly According to IS 456-2000, the reinforcement of RSCC beams with a length of 1200 mm, width of 150 mm and 250 mm high were designed and tested under two-point loading at 28 days. The beams were supported by simple support with a span of 1000 mm and it was subjected to
two-point loading. During two-point load test the structural characteristics viz., load-de�lection, studied. failure modes, load characteristics, de�lection ductility index and degradation in stiffness were The experimental results showed that RSCC beams have shown better results in all structural
behaviour characteristics with 10% alcco�ine and 25 % �ly ash. Keywords: structural behavior Two-point loading; load characteristics; alcco�ine; �ly ash; �lexural parameters;
Abbreviations
RSCC Reinforced self-compacting concrete NC Normal concrete FA Fly ash
AL RC Reinforced concrete Alcco�ine DI Ductility index
63 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings Introduction It is well-known that beam elements are the important ductility compared to the normal beams under two-point loading. components in the concrette structures that carry transverse loads. As a result, research has been carried out over the last few decades Mithra et al. [7] explored the structural behaviour with GGBFS on reinforced concrete beams to enhance the strength properties based reinforced SCC beams a partial substitute for OPC and addition of high range water reducer. The goal was to examine the torsion strength, etc. Plain concrete is strong in compression but such as modulus of elasticity, shear strength, �lexural strength and weak in tension because it includes many micro-cracks [1]. These �lexural behaviour of simply supported SCC beams were cast with loading. The effect of GGBFS, which ranges from 0 to 50 percent as micro-cracks spread into the concrete while applying loads. As a HYSD bars. Data were collected for load-de�lection under two-point result, structural members with plane concrete cannot withstand a partial substitute of cement, was examined preliminarily. It was the tensile stresses that have developed owing to the force applied noted that the primary crack load was improved for the SCC beams without the addition of reinforcement elements [2].The addition of with 30-40% GGBFS and 40% GGBFS substituted was shown good supplementary cementitious materials increases its load-carrying performance compared to all other beams. capacity, ductility, and stiffness while reducing crack propagation In this work an attempt was made to study the structural and crack development in the structural concrete elements. In the last 30 years, concrete manufacturers have developed a new generation of composites with high mechanical characteristics and characteristics viz., load-de�lection, failure modes, load stiffness of SCC reinforced concrete beams made using varying environmental resistance [3]. characteristics, de�lection ductility index and degradation in
cement. Vidivelli and Gobi [4] aimed to compare the structural behaviour dosage of alcco�ine and �ly ash as a constant replacement for of self-curing and self-compacting concrete beams. They have used Materials and Methods fume for the cement substitution, and quarry dust to substitute the mineral admixtures such as limestone, class F �ly ash and silica The materials used for concrete production were ordinary curing and self-compacting concrete beams. Twelve mixes were �ine aggregate. They have developed a technique to analyze self- size of 4.75 mm and coarse aggregate with a maximum aggregate used to prepare the normal concrete beams, self-curing concrete Portland cement, alcco�ine, �ly ash, natural sand with maximum size of 12 mm. The mix ingredients of reinforced self-compacting beams and self-compacting concrete beams. Different tests have concrete (RSCC) mixes are shown in Table 1. The quantities of been performed for the strength properties of concrete. The ANN and yield load. Self-curing and self-compacting concrete beams cement, alcco�ine and �ly ash are in different quantities for all modelling has been carried out to compare the de�lection, ultimate water and chemical admixture are same for all concrete mixtures showed better performance, and the ANN model showed an error concrete mixes. The quantities of �ine aggregate, coarse aggregate, as followed by 863.36 kg/m3, 721.60kg/m3, 179.64 kg/m3 and 5.99 of 0.8 to 16.6%, only with those of experimental tests. kg/m3, respectively. Saifullah et al. [5] were studied the structural behaviour of The formwork with wood material comprises of inner dimensions 150 mm * 250 mm * 1200 mm was prepared. The studies under four-point loading. Computer-based analysis of the beam elements experimentally for �lexure and load-de�lection prepared formwork should be leak proof otherwise poured SCC tests performed in the lab was done using ANSIS and SAS 2005. Empirical analyses have been accomplished on reinforced beams state. The reinforcement details as shown in Figure 1 consists of of over, balanced and under reinforcements. The acceptable range would escape out from the formwork science it is �luid in green two number of 10 mm diameter bas as bottom longitudinal (main) of error was observed from the computer-based outcomes. The tension reinforcement and two number of 8 mm diameter bar as primary crack was observed at 0.45 L from the left end support. hanger bars provided on the compression face with clear cover of 25 mm. the shear reinforcement consists of 8 mm diameter bar section in concrete beams. The maximum de�lection was observed in the balance reinforced with two legged stirrups at 165 mm centre to centre. Jeenu et al. [6] researched the bending behaviour of hybrid The inner face of the formwork was rushed with oil before placing reinforcement and concreting. The reinforcement skeleton �ibre added SCC beams. The prototype concrete beams have been produced without �ibres, with optimum percentages of macro and were cast. Once the prepared SCC mix attained desired workability, under two-point loading. The concrete beam specimens with 0.75% was placed in the formwork with a cover of 25 mm. Total �ive beams hybrid �ibres were produced to investigate the �lexural behaviour then it was poured in the beam mould without compaction. SCC in hardened state was shown in Figure 2. macro �ibres were seen to be good, but when 50% macro �ibres mechanical properties of concrete have been improved with micro were substituted with micro�ibres, better results were seen. The The formwork was removed after the duration of 24 hours of
�ibres addition. With hybrid �ibres in SCC beams performed well 64 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings the water tank for the hydration period of 28 days to attain adequate strength. The normal water curing was carried out for all beam concreting. The beam identi�ication was given by marking NC, SCC0, SCC5, SCC10 and SCC15. The beam specimens were immersed in specimens.
Table 1: Mix proportions for RSCC beams
Mix Cement Fly ash Alcco�ine Super Coarse Fine Water plasticizer aggregate aggregate NC 384 0 0 0 1139 639 202 SCC0 349.3 149.7 0 SCC5 331.8 149.7 17.40 5.99 721.60 863.36 179.64 SCC10 314.3 149.7 34.93 SCC15 296.9 149.7 52.39 *All quantities are in kg/m3
Figure 1: Reinforcement detailing of RSCC beams
Figure 2: SCC in hardened state
65 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
After 28 days of curing, the beam specimens were taken out from the water tank. The surfaces of beam specimens were made dry by placing it in the open atmosphere for the minimum duration of 3 hours. Once its surface became dry off, the position of support rollers with a projection of 100 mm on either ends, the span of the beam (L), mid span (L/2) and the position of loading rollers say L/3 were indicated on the longitudinal section of the beam. The loads were applied at two points of the beam and the distance between the rollers is L/3 as shown in Figure 3. The beams were tested up to failure.
Figure 4:
Load-de�lection curves
Figure 3: Two-point loading setup
Results From an experimental investigation on the beams, the most important independent parameter to understand the behaviour of along the beam at L/3 points at every load stage of reinforced SCC Figure 5: Load characteristics of RSCC beams beam was its load-de�lection pro�ile. De�lections were measured Table 2: Displacement ductility index values of RSCC mixes beams. For present study, the load-de�lection plot was prepared at beams. The values of test results of all beams from each mix tested Displacement (mm) L/3 position. Figure 4 shows the load-de�lection curves of RSCC Beam Yielding Ultimate service load, yield load and ultimate load for all the beams are Designation DDI for �lexure at the age of 28 days. Comparison of primary crack load, state state in all the tested beams. Crack patterns of RSCC beams are shown NC 5.36 8.33 1.55 shown in Figures 5. Both �lexure and shear failure were observed in Figure 6. Ductility is the ability to sustain inelastic deformation SCC0 3.80 8.47 2.23 without substantial decrease in the load carrying capacity. The SCC5 4.46 9.57 2.15 SCC10 4.86 7.94 1.63 ductility factors of the tested beams were calculated by �inding the SCC15 4.61 8.08 1.75 ratio of de�lection at the ultimate load to the de�lection at the yield indices are illustrated in Table 2.The ratio between the load and the load. The mid span de�lection at yield and ultimate loads, ductility Discussion The stiffness is calculated at two stages such as yield and ultimate corresponding de�lection gives the stiffness of the beam specimens. Load-de�lection behaviour of RSCC load level. The variation of stiffness in all the three stages for all the 5 beams are presented in Table 3.The moment at the ultimate load capacity of all the beams are given in Figure 7. Figure 4 shows the load-de�lection curves of RSCC beams. From show mainly two kinds of behaviours, i.e., linear and non-linear [8]. Figure 4, it can be seen that the de�lection curves of RSCC beam First part (i.e., linear) curve indicates the un-cracked characteristic of the beam upto the initial crack load. In contrast, the second part 66 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings (i.e., non-linear) of RSCC beam represents the cracked beam behaviour after initial crack up to the specimen failure. In this research, it is also observed that the load-de�lection curves of RSCC beams have mainly two turning points representing the behaviour of RSCC beams. ductility behavior of RSCC beams [9]. The ultimate load can be obtained at the second turning point. After the second turning point First turning point indicates elastic behavior and second turning point (i.e., from �irst turning point to second turning point) indicates represent the fracture behavior of beam specimen. The
ultimate de�lection was seen at mid span of the RSCC mixes as shown in Figure 4. For 250 mm depth RSCC beams, the normal concrete mix showed a de�lection of 8.33 mm at the ultimate load of 129 kN, whereas SCC0, kN, 160.87 kN, 171.248 kN and 162.12 kN, respectively. SCC5, SCC10 and SCC15 mixtures showed the de�lections of 8.47 mm, 9.57 mm, 7.944 mm and 8.0898 mm at the ultimate load of 149.27
Figure 6: Cracking pattern of RSCC beams
Figure 7: Ultimate moment carrying capacity results
Table 3: Relative stiffness degradation
Beam Stiffness (N/mm) Variation in stiffness Designation Yielding Ultimate degradation state state NC 19589.55 15486.19 0.790533 SCC0 28131.58 17623.38 0.626462 SCC5 27959.64 16809.82 0.601217 SCC10 30637.86 21566.75 0.703925 SCC15 25412.19 20064.36 0.789556
67 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings Load characteristics dosage increases the overall stiffness of beam increases. Table 3 shows that stiffness descends very fast at initial stage till cracking Self-compacting reinforced concrete beams were failed in both point and after cracking point it becomes slower until it reaches ultimate load of RSCC beams are shown in Figure 5. From IS 456- �lexure and shear. Primary crack load, service load, yield load and 2000, the service load was determined by using factor of safety 1.5. failure point. It is observed that in case of beam with alcco�ine and �ly ash the yield cracking stiffness and ultimate stiffness were ash. The stiffness degradation of SCC0 mix specimen showed 21.5% higher values when compared to beam without alcco�ine and �ly The addition of �ly ash and alcco�ine improved its homogeneity lesser than the normal mix specimen, whereas SCC5, SCC10 and due to interlocking effects between mortar with aggregate and and �low-ability and enhanced the ultimate �lexural strength SCC15 mixtures showed the degradation in stiffness of 24%, 11% reinforcement in RSCC beams. Figure 5 shows that the service and 1.26%, respectively compared to the normal mix specimen. loads of SCC0, SCC5, SCC10 and SCC15 are found to be enhanced by 15.70%, 24.69%, 32.74%, and 25.67% respectively, when Ultimate Moments compared to that of beam with mix NC. The crack load of SCC beams The experimental ultimate moment carrying capacities of all with mix SCC0, SCC5, SCC10 and SCC15 are found to be improved the tested beams are shown in Figure 7. It was observed that as by 14.10%, 23.921%, 56.40% and 42.18%, respectively, when compared to that of beam with mix NC. The yield load of SCC beams moment carrying capacity increases when all other parameters are with mix SCC0, SCC5, SCC10 and SCC15 are found to be enhanced by constant �ly ash quantity and alcco�ine dosage increases the ultimate 1.85%, 18.82%, 41.83% and 35.05%, respectively, when compared to that of beam with mix NC. The same pattern was followed by the kept constant [17]. It was also found that �ly ash and alcco�ine play ultimate load-carrying capacity in all SCC mixes [10]. a signi�icant role in the beam’s ultimate moment carrying capacity. Ultimate moment carrying capacity of the beam without alcco�ine and �ly ash is found to be less than the beam with alcco�ine and �ly Failure mode and crack pattern been enhanced by 15.68%, whereas the combination of constant ash. With 25% �ly ash addition, the moment carrying capacity has
and 15% enhanced by 24.67%, 32.72% and 25.65% compared to observed for all the beams for low loadings in mid-span at bottom �ly ash quantity with varying dosage of alcco�ine from 5%, 10% From Figure 6 showed that the �lexural cracking was initially normal concrete mix, respectively [18]. zone, indicating that steel reinforcement did not play any signi�icant Conclusions increases, the beam’s load-carrying capacity and ultimate failure role in enhancing cracking load. After initial �lexure crack, as load On the basis of the present investigation, the following Conclusions are drawn wereHairline observed cracks due tooccurred shear and initially �lexure. in the pure bending zone •
The load-de�lection behaviour of RSCC beams were occurred and the existing cracks extended and spread from the during the �irst crack load. As the load increased, new cracks studied with the addition of constant dosage of �ly ash bottom of the beam (tension zone) to top of the beam (compression 0-15% by mass). (i.e., 25% by mass) and varying dosage of alcco�ine (i.e., zone) and spalling of concrete was examined in the compression • The ultimate load carrying capacity of RSCC beams were zone. The width of the crack has been increased to a greater extent at ultimate load. Figure 4 displays the crack patterns of tested increment it decreased. beams evaluated at ultimate loads. enhanced up to 10% alcco�ine addition and further • Ductility index were observed in RSCC beams. The combination of shear and �lexural mode of failures • The load characteristics (i.e., primary crack, service, yield Ductility index is presented in the ratio of de�lection at ultimate and ultimate load) of RSCC beams enhanced with constant curves and presented in Table 2. The deformation of SCC10 and stage to yield stage. DI has been calculated from the load-de�lection SCC15showed the medium ductility index values compared to SCC5 �ly ash and alcco�ine dosage from 0-15% replacement. mix, whereas SCC0 concrete mix showed the high DI value compared • to the other concrete mixes. The highest yielding capacity or the values in stiffness degradation compared to normal RSCC beams with alcco�ine and �ly ash showed lesser concrete mix. property of ductility was exhibited in SCC beams with alcco�ine Degradation in stiffness and �ly ash when compared with normal concrete beams [12-15]. Acknowledgment
Relative stiffness values at yielding and ultimate load points are The authors acknowledge the facilities provided by Jawaharlal calculated and are shown in Table 3.Secant stiffness is used to do Nehru Technological University, Anantapuramu and Annamacharya stiffness degradation analysis. It is observed that as the alcco�ine 68 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Institute of Technology and Sciences, Tirupathi for research works 9. EC Constantin, ET Georgia, JP Stavroula. Behaviour of rehabilitated RC beams with self-compacting concrete Engineering (CE). The authors also wish to express their gratitude jacketing – analytical model and test results. Constr in the �ield of concrete technology at the Department of Civil to ASTRRA chemicals in Chennai, India for providing materials for Build Mater. 2014;55:257–273. DOI: 10.1016/j. this study. conbuildmat.2014.01.031
10. HK Young, BDH Mary, T David. Flexural behavior of high- Declaration early-strength self-consolidating concrete pretensioned bridge girders. J Bridge Eng. 2015;20(2):04014064. DOI: interests or personal relationships that could have appeared to 10.1061/(ASCE)BE.1943-5592.0000644 The authors declare that they have no known competing �inancial 11. Thomsen H, Spacone E, Limkatanyu S, Camata G. Failure mode analyses of reinforced concrete beams strengthened in�luence the work reported in this paper. Con�lict of Interest polymers. Journal of Composites for Construction. in �lexure with externally bonded �iber reinforced 2004;8(2):123–131. doi: 10.1061/ (ASCE) 1090- 0268 We wish to con�irm that there are no known con�licts of interest (2004)8:2(123) associated with this publication and there has been no signi�icant outcome. 12. T Muralidhara Rao, N Srikar, G Sukesh Reddy, B Praveen. �inancial support for this work that could have in�luenced its Ductility of reinforced concrete beams. CVR Journal of References Science and Technology. 2015;9(12). DOI: 10.32377/ cvrjst0902 1. and Raw or Calcined Natural Pozzolan for Use in Concrete. 13. Chenglin Wu, G Chen, JS Volz, RK Brow, ML Koenigstein. ASTM C618-17a. Standard Speci�ication for Coal Fly Ash Annual Book of ASTM Standards. 2017;1–5. DOI: 10.1520/ Global bond behavior of enamel-coated rebar in concrete C0618-19 beams with spliced reinforcement. Constr Build Mater. 2013;40:793–801. 2. Hassan AAA, Hossain KMA, Lachemi M. Structural assessment of corroded self- consolidating concrete 14. M Rakhshanimehr, MR Esfahani, MR Kianoush, BA beams. Eng Struct. 2010;32(3);874-885. Mohammadzadeh, SR Mousavi. Flexural ductility of reinforced concrete beams with lap-spliced bars. Can J Civ 3. He J, Jie Y, Zhang J, Yu Y, Zhang G. Synthesis and Eng. 2014;41(7):594–604 characterization of red mud and rice husk ash-based geopolymer composites. Cement Concrete Compos. 15. An W, Saadatmanesh H, Ehsani MR. RC beams strengthened 2013;37:108-118. with FRP plates. II analysis and parametric study. Journal of Structural Engineering.1991;117(11):3434–3455 4. Vidivelli B, Gobi TKT. Flexural Behaviour of Self Compacting and Self Curing Concrete beams. International Journal of 16. Alagusundaramoorthy P, Harik IE, Choo CC. Flexural
reinforced polymer sheets or fabric. Journal of Composites behaviour of RC beams strengthened with carbon �iber 5. Scienti�icSaifullah &I, EngineeringHossain MA, Research. Rashid MH. 2013;4(12):850-855. Experimental and for Construction. 2003;7(4):292–301. Analytical Investigation of Flexural Behavior of Reinforced Concrete Beam. 2011;11(1):146-153. 17.
6. G Jeenu, UR Reji, V Syam Prakash. Flexural Behaviour Skuturna, T Valivonis, J Vainiūnas, P Marčiukaitis, G Daugevičius M. Analysis of de�lections of bridge girders of Hybrid Fibre Reinforced Self-Compacting Concrete. Journal of Road and Bridge Engineering. 2008;3(3):145– strengthened by carbon �iber reinforcement. The Baltic 32nd Conference on Our World in Concrete & Structures. 151. Singapore. 2007. 18. 7. Mithra M, Ramanathan P, Muthupriya P, Venkatasubramani equations of beams externally strengthened with FRP Toutanji H, Zhao L, Anselm E. Veri�ications of design R. Flexural Behavior of Reinforced Self Compacting composites. Journal of Composites for Construction. Concrete Containing GGBFS. International Journal of 2006;10(3):254–264. Engineering and Innovative Technology. 2012;1(4):124- 129.
8. AAA Hassan, KMA Hossain, M Lachemi. Structural assessment of corroded self-consolidating concrete beams. Eng, Struct. 2010;32(3):874–885. doi. org/10.1016/j.engstruct.2009.12.013
69 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Buckling Bearing Capacity of Steel Plate in Steel-Concrete-Steel Sandwich Composite Tower under Axial Compression
Yu Hang. WANG a, Guo Bing. LU a, Shu Qi. WANG a and Ji Ke. TAN a*
aSchool of Civil Engineering, Chongqing University, Chongqing, China
*Corresponding author: Ji Ke. TAN, School of Civil Engineering, Chongqing University, Chongqing, China, Email:
Abstract In order to solve the problem that the traditional steel tower is prone to collapse due to local buckling under axial compression, considering the principle of composite structures, a new type of steel-concrete-steel (SCS) sandwich composite tower for wind power tower structure is proposed in this paper. In order to study the buckling bearing capacity of steel plate in SCS sandwich composite tower, three specimens were designed considering the key parameters of the curvature (the reciprocal of radius) and the spacing-to-thickness ratio (the ratio of vertical stud spacing and surface steel plate thickness). The inner and outer steel plates are connected to the concrete by the studs, and the concrete does not directly bear the vertical load and only provides brace to the steel plates. The specimens were tested under axial compression, the failure modes and load-displacement curves of the specimens were achieved. The test results show that: (1) local buckling failure between studs occurs in all specimens (2) when the spacing-to-thickness ratio is 65, the buckling bearing capacity of the specimen with an
when the inner steel plate with a curvature of 0.001, the spacing-to-thickness ratio changes inner steel plate curvature of 0.001 is 73% higher than that of the �lat steel plate specimen; (3) from 109 to 65, and the buckling capacity of the specimen increases by 24%.
Keywords: Axial Compression; Buckling Capacity; Curvature; Spacing-To-Thickness Ratio; Steel-Concrete-Steel Sandwich Composite Tower
1. Introduction
Wind energy is a kind of clean renewable energy; wind power the buckling of steel plates occur only within the spacing between generation is the most widely used and the fastest-growing new studs, which greatly improves the buckling bearing capacity of steel energy generation technology. As a main force suffering structure tower. in the wind turbine, the tower not only supports the weight of nacelle and rotor, but also bears the wind load and dynamic load. Therefore, the tower plays an important role in the stable operation of the whole machine. At present, steel tower is the most common form of large wind power tower, which is prone to collapse due to local buckling under the action of complex loads, as shown in Fig. 1[1]. In order to solve the problem that the traditional steel tower is prone to collapse due to local buckling under axial compression, considering the principle of composite structures, a new type of steel-concrete-steel (SCS) sandwich composite tower for wind power tower structure is proposed in this paper, as shown in Fig. 2. The inner and outer steel plates of SCS sandwich composite tower are connected to the concrete by the studs, giving full play to the material advantages of concrete and steel. At the same time, concrete acts as a brace for steel plates, and the arrangement of studs makes Figure 1: Collapse of steel tower due to local buckling
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and the axial load is only applied on steel plates, while the concrete only provides a brace to the steel plates, so as to investigate the buckling bearing capacity of steel plate in SCS sandwich composite tower. 2. Test Programe
2.1 Specimen design
Three specimens were designed in this test, and the section centroid of the steel plate coincided with that of the end plate. SP2 was the compared specimen, SP1 was aimed to investigate the effect of the spacing-to-thickness ratio, and SP3 was aimed to investigate the effect of the curvature. The detailed parameters of specimens are listed in Table 1, and the geometric structures of specimens are presented in Fig. 3 and Fig. 4.
Table 1: Detailed parameters of specimens
Sv/t n t(mm) ht(mm) Ri(mm) Si(mm) So(mm) Sv(mm) -
SP1 2.30 103.78 1000 244 269 250 109
Figure 2: Schematic diagram of SCS sandwich composite tower SP2 2.30 103.00 1000 147 161 150 65
A great number of experimental and theoretical studies on the buckling performance of SCS sandwich composite structure could SP3 2.28 103.72 150 150 150 65 be found in the literature. Based on the existing experimental data ∞ ratio limit of steel plate in SCS sandwich composite wall to prevent Where: t-thickness of the steel plate; h -thickness of the steeland �inite plate element buckling analysis, before yield.Zhang Based et al. [2]on thegave elastic the slenderness thin plate t specimen; Ri-radius of the inner steel plate; Si-spacing of studs on theory and the principle of energy standing value, Nie et al. [3] the inner steel plate along the arch direction; So-spacing of studs on derived the critical load of local instability of composite plate, and the outer steel plate along the arch direction; Sv-spacing of studs on obtained the calculation formulas of maximum stud spacing and the inner and outer steel plate along the height direction. minimum concrete plate thickness under axial compression. Huang et al. [4] conducted an experimental study on the axial compression To ensure that the axial force would not be transferred to the lightweight cementitious composite material and proposed an improvedperformance bearing of SCS capacity sandwich calculation composite formula wall basedin �illed on with Euro ultra- code withconcrete a thickness in�ill, a of polytetra�luoroethylene 10 mm were placed between (PTFE) the layer adjacent was addedstuds. 4 and AISC 360. Liu et al. [5] and zhang et al.[6] respectively carried Inbetween order to the accurately steel plate control and the the concreteheight of in�ill, each andlayer form of concrete boards out axial compression tests on SCS sandwich composite walls with and facilitate the spread of form boards, a 50mm × 50mm hole was different spacing-to-thickness ratio, and gave the formula of the opened at the design height of the side plate of form boards. After spacing-to-thickness ratio limit to prevent steel plate local elastic the concrete was poured, the hole was welded with small steel plate. buckling. Yang et al. [7] conducted axial compression tests on 10 SCS sandwich composite walls. Considering the arrangement of studs and spacing-to-thickness ratio as variables, a theoretical 28-day cubic strength of concrete was 37.3MPa. The material grade model based on euler equation to predict the buckling stress of steel of steelThe platesgrade wasof the Q235B, concrete and in�ill the measured was C30, andyield the strength characteristic of steel plates was proposed. Ding et al. [8] conducted axial compression plates was 332.33 MPa, the ultimate strength was 455.33 MPa. tests on SCS sandwich composite walls only loaded on concrete, angle between stud head and wall axis on bearing capacity. 2.2 Specimen processing and studied the in�luence of steel plate thickness, stud length and Auxiliary stiffeners were welded on the outside of steel plate to The above researches mainly focus on the load cases of SCS prevent deformation, and the studs were welded on the inside of sandwich composite structure where the axial force only loaded on steel plate (Fig. 5(a)). After a PTFE layer was pasted on steel plate the concrete or the axial force loaded on the concrete and steel. No (Fig. 5(b)), the steel plates and end plates were welded together to study has been made on the load case where the axial force only complete the processing of steel specimen. As shown in Fig. 5(c), loaded on the steel, and no one has studied the effect of curvatureon form boards with a thickness of 10 mm were placed between the the buckling bearing capacity of steel plate in SCS sandwich adjacent studs when pouring concrete. The concrete was poured composite structure. Therefore, three specimens were designed through holes reserved on the upper end plate, and workers considering the key parameters of the curvature (the reciprocal of compacted from bottom to top with a vibrating rod. Finally, welding radius) and the spacing-to-thickness ratio (the ratio of vertical stud spacing and surface steel plate thickness). Among them, the inner the specimen processing. and outer steel plates are connected to the concrete by the studs, the small steel plates (Fig. 5(d)) at the hole of the side plate �inished
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(a) Overall diagram (b) Inner diagram
Figure 3: Geometric structures of specimens
(a) Section diagram of �lat plate specimen
(b) Section diagram of curved plate specimen (c) A-Asection
Figure 4: Inner structure of specimens
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(a) Welding studs (b) Pasting PTFE layer
(c) Pouring concrete (d) Welding small plates
Figure 5: Specimen processing
2.3 Test equipment and measurement scheme The compression tests were conducted by servo controlled electro hydraulic testing machine in the Structural Laboratory of Xi’an University of Architecture and Technology. The test equipment and measurement scheme are shown in Fig. 6.The axial force of the specimen was measured by the force sensor of the device, and the axial displacement was measured by Linear Variable Differential Transformer (LVDT) displacement meter arranged symmetrically at the center of the inner and outer steel plates. Monotonic axial loading was applied in the test, which could be divided into two stages: preloading and formal loading. The main function of preloading was to check whether the specimen was uniformly stressed and whether the displacement meter worked properly. The load of preloading was 10%nominal bearing capacity (equal to fyAs). After the preloading, the formal loading was loaded by displacement control. When the specimens were
signi�icantly deformed and severely damaged, the tests were stopped.
(a) Test equipment (b) Measurement scheme
Figure 6: Test equipment and measurement scheme
73 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings 3. Test Phenomena and Failure Mode and outer steel plates decreased. When the inner steel plate with a curvature of 0.001, the spacing-to-thickness ratio changed from 109 to 65, the buckling half-wavelength of inner steel plate decreased. interval of the second row of studs on the inner steel plate began to Before the peak load of specimen SP2, the �irst horizontal the upper right of outer steel plate. After the peak load of 955.3kN, thebuckle, curve and at the uppersteel plate right buckled of outer below steel plate the �irst was rowpulled of studsthrough. on With the increase of the load, the curve at the second row of inner steel plate was pulled through between the horizontal studs. When the load continued to increase, the curve on the inner and outer steel plate was pulled through at the left and right side plate. The
�inal failure mode of specimen SP2 is shown in Fig.7. (a) Inner steel plate (b) Outer steel plate
Figure 9: Failure mode of specimen SP3
4. Buckling Bearing Capacity
The buckling bearing capacity (maximum bearing capacity) of the specimens is listed in table 2, and the load-displacement curves are shown in Fig. 10.It can be seen that when the spacing-to- (a) Inner steel plate (b) Outer steel plate thickness ratio is 65, the buckling bearing capacity of the specimen with an inner steel plate curvature of 0.001 is 73% higher than that Figure 7: Failure mode of specimen SP2 The vertical stud spacing of SP1 decreased. Before the peak 0.001, the spacing-to-thickness ratio changes from 109 to 65, and load, the inner steel plate began to buckle between the studs along theof the buckling �lat steel capacity plate; whenof the the specimen inner steel increases plate withby 24%. a curvature of of studson the upper left of outer steel plate. After the peak load of When the spacing-to-thickness ratio is constant, the buckling 771.4kN,the diagonal, the followedcurve at theby theupper steel left plate of outer buckledbelow steel plate the was �irst pulled row bearing capacity of the curved steel plate specimen because of through, and three intervals of studs on the upper left of inner steel plate buckled.When the load continued to increase, the upper right specimen. The arrangement of the studs limits the buckling failure of inner steel plate began to buckle, and the steel plate on the top oftheout-of-plane the steel plates stiffness only occur is higher between than adjacent that of studs. the �lat The steel decrease plate of the spacing-to-thickness ratio means the decrease of the distance specimen SP1 is shown in Fig. 8. between studs. In this way, the buckling half-wavelength will be of the left plate and right plate buckled. The �inal failure mode of reduced accordingly. The decrease of the buckling half-wavelength is converted to the increase of buckling bearing capacity.
Table 2: Buckling bearing capacity of specimens Specimen R (mm) S /t P (kN) No. i v u SP1 1000 109 771.4 SP2 1000 65 955.3 SP3 65 550.3
(a) Inner steel plate (b) Outer steel plate ∞ Figure 8: Failure mode of specimen SP1 load, the long curve occurred on the lower middle of outer steel plate.Specimen After the SP3 peak was load a �lat of steel550.3kN, plate the specimen. long curve Before occurred the peak on the lower middle of inner steel plate. When the load continued to increase, the curve on the inner and outer steel plate was pulled specimen SP3 is shown in Fig. 9. through at the left and right side plate. The �inal failure mode of The test phenomenon shows that local buckling failure between the studs occurred on the steel plates of all specimens. The arrangement of studs limited the buckling failure of steel steel plate specimen, the curved steel plate specimen had a certain out-of-planeplates only occur stiffness, between thus adjacentthe buckling studs. half-wavelength Compared with of the inner �lat Figure 10: Load-displacement curve
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5. Conclusion References
In this paper, the axial compression tests of three steel-concrete- 1. Pan FS, Wang FW, Ke ST, Tang G. Buckling analysis and stability steel sandwich composite tower specimens only loaded on steel design of wind turbine tower with geometic imperfections. were successfully conducted, and the following conclusions could Acta Energiae Solaris Sinica. 2017,0254-0096(2017)10-2659- be obtained through the observation of experimental phenomena 06. (in Chinese) and the analysis of test results: 2. Zhang K, Varma AH, Malushte SR, Gallocher S. Effect of shear connectors on local buckling and composite action in steel (1) Local buckling failure between studs occurs on the steel concrete composite walls. Nuclear Engineering and Design. 2014;269:231-239. the curved steel plate specimen has a certain out-of-plane stiffness, thusplates the of allbucklinghalf-wavelength specimens. Compared with of inner the �lat and steel outer plate steel specimen, plates 3. Nie JG, Li FX. Study on the Stability of Steel-Concrete decreases. When the inner steel plate with a curvature of 0.001, the CompositePlates under Uniaxial Compressed Load. China spacing-to-thickness ratio changes from 109 to 65, the bucklinghalf- Railway Science. 2009;30(6):27-32. (in Chinese) wavelength of inner steel plate decreases. The decrease of the 4. Huang Z, Liew JYR. Compressive resistance of steel-concrete- buckling half-wavelength is converted to the increase of buckling steel sandwich composite walls with J-hook connectors. bearing capacity. Journal of Constructional Steel Research. 2016;124:142-162.
(2) When the spacing-to-thickness ratio is 65, the buckling 5. Liu YB, Wang S, Liu JB, Niu Q. Experimental study on local bearing capacity of the specimen with an inner steel plate curvature buckling behavior of composite walls with double steel plates inner steel plate with a curvature of 0.001, the spacing-to-thickness Sciences). 2017;45(4):317-323. DOI: 10.3876/j.issn.1000- and �illed concrete. Journal of Hohai University (Natural ratioof 0.001 changes is 73% from higher 109 than to 65, that and of thethe �latbuckling steel plate.capacity When of the 1980.2017.04.006.(in Chinese) specimen increases by 24%. 6. Zhang YJ, Li XJ, He QM, Yan X. Experimental study on local
Acknowledgements under concentric loads. China Civil Engineering Journal. 2016;49(1):62-68.stability of composite (in walls Chinese) with steel plates and �illed concrete The research is supported by the Project of Fok Ying Tung 7. Yue Y, Liu J, Fan J. Buckling behavior of double-skin composite Education Foundation (171066) 、National Natural Science walls: An experimental and modeling study. Journal of Foundation of China (51890902) and Chongqing Science and Constructional Steel Research. 2016;121:126-135. Technology Bureau (cstc2019jcyj-zdxm0099). 8. Ding LT, Seismic behavior of double steel plate-intersect studs-concrete composite shear wall. Institute of Engineering Mechanics, CEA. 2014. (in Chinese)
75 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Planning and Mapping of a Multi Modal Integrated Transportation System for Metro Station at Dadar, Mumbai India by Using Open-Source GIS
S Bala Subramaniyam*, Reshma Raskar-Phule
Sardar Patel College of Engineering, Bhartiya Vidya Bhavans, Andheri west, Mumbai, India,
*Corresponding author: S Bala Subramaniyam, Sardar Patel College of Engineering, Bhartiya Vidya Bhavans, Andheri west, Mumbai, India, Email:
Abstract GIS can be widely used in transportation policy and planning agencies, especially among urban transportation organizations. GIS offer transportation planners/decision makers a medium for storing, displaying, analysing, modelling, and simulating various spatial/attribute data on population, land uses, and travel behaviour. In fact, GIS address potential transportation
issuesThe more present ef�iciently, research effectively, seeks to and investigate economically spatial than accessibility existing methods. of a multimodal transport system in an urbanised area with respect to the proposed or planned metro railway project
multimodality in transport are interpreted such as bus rapid transport system, mass transit in the city of Mumbai, India. From literature and current practices various factors in�luencing system, integrated public transport system, private transport systems, pedestrian walking and more. The research aims to identify key factors in these available transport systems which may
trend and pattern of use, and importantly effectiveness for managing spatial natural disasters affect the ef�iciency or effective use of the proposed metro project such as population, location,
suchConsidering as earthquakes the andabove �loods factors, and aman-made multimodal disasters transport like networkterrorist attacks.system is developed and proposed for a metro station like Dadar located in Mumbai, India that is subjected to high density
open source geographic information system (GIS) software, Quantum GIS (QGIS). The developed and variety of traf�ic population. The spatial analysis, planning and mapping is carried out in map proposes and shows shortest accessible routes, subways, pedestrian walkways, basement public parking lots, station integration and management for a forecasted population.
1. Introduction
The advancement of cities is uncontrollable not spontaneous environment. Due to increased mobility of people, goods and but are guided by human interaction and physical infrastructure. increasing number of automobiles, lack of good transportation services urban areas are facing issues like traf�ic congestion, to carry the goods and for services. system and lack of integration between different transportation For cities and towns to function ef�iciently, accessibility is essential system. An urban area is a web of various activities and people, where the transport system connects the two. Population explosion, There is a shift from conventional transportation practice to industrial growth and employment opportunities have resulted Modern transportation planning practices which are based upon into unplanned urban sprawl, which has degraded the urban the accessibility concept. It not only helps to improve transport
76 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings infrastructure but also improves the travel behaviour and accessibility to various land uses.
1.1 Study area railway and bus service hub with local and national connectivity. Dadar is a prominent railway terminus on both central and western lines Dadar is the �irst planned area of Mumbai. It is a densely populated residential and shopping neighbourhood. It is also a prominent of Mumbai railway network. It is the only common railway station for both central and western lines making it a transit point for many passengers. Currently Metro 3 project is under construction which is completely underground metro rail project in Mumbai.
Figure 1: Map showing study area
2. Methodology A modal survey as carried out for which Questionnaire was prepared (refer annexure) and survey was carried out at Andheri . Site metro station and at Dadar station during the peak hours. The main
The work �low for the present study is shown in Figure2 trips of work. visits were carried out frequently during the work to �ind out aim of the survey was to �ind main mode of transport used during Integrated Public Transports (IPT), to check ease of access to traf�ic congestions, bus-routes, pedestrian walkways, Modal share, proposed metro station. 2.1 Data collection
The data collection was done using origin and destination survey. Spatial and Non-spatial data was collected for the proposed The existing land use pattern with the existing transportation metro station through different means and methods such as physical facilities was studied. The spatial data involves geospatial data or on-site survey and through various online and government like location size and shape whereas the non-spatial data are the sources as described here. numbers characters and logic types.
77 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Figure 2:
Flow chart showing �low of work carried out 2.1.1 Non-Spatial or Physical Data Collection 767 buses pass daily on various routes from the proposed metro station. Figure 4 shows a sample route study of bus Route for Bus A detailed physical survey for 3 hours has been carried out for no.86 -Bandar bus station to Back Bay depot. collection of location, frequency of use, and existing condition of the transportation routes in the surrounding areas of the proposed Table 1 depicts the bus stops, the origin and destination, underground Dadar metro station. A real-time study was carried frequency and journey time. In addition to this, it is observed that out for the study of existing pattern of vehicular movement through MCGM has permitted street parking at various locations. According physical survey and google maps at the surrounding areas. It is seen to the on-site surveys carried out, following congestion points were from Figure 3; the Google map shows that the area is subjected to found: in front of Shivasena Bhawan, Kabutar Khana, Patkar Guruji area on the same routes during a peak hour gave an approximate medium to heavy traf�ic during peak hours. The traf�ic survey of that Chowk, Kavi Keshavsut �lyover. frequency to the vehicular movement, say red colour indicates 200 at the ends of Dadar Metro Station on the Gokhale Road and the vehicles per hour and orange colour indicates 100 vehicles per Pedestrian traf�ic is also observed, especially during peak hours, footpaths were occupied by street vendors. The network of roads and footpaths is almost properly planned and are in good condition. hourNext, forming the number traf�ic congestion. of stops, their location and the frequency of the The study of existing street furniture, public facilities, and street routes is studied with the help of physical survey and M-indicator lighting shows that not enough street furniture like street lights, mobile application. The study shows that there are total 16 bus bollards, recycle and litter bins, seating, drinking water facility, stops in the surroundings of the proposed metro station and a total washrooms, planters, etc are available whereas the area provides
78 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings good amount of existing green landscape with available parks and gardens such as Shivaji park, Kotwal gardens and Matoshri Rama bai Thakare Udyan.
Considering the safety and security facilities with respect to the proposed metro station, it is noted that Dadar Fire Station is located at a distance of 2.2 km from the Dadar metro station, Dadar police station is at a distance of 1.6 km from the metro station, security cameras are available at various spots such as Dadar railway station, Tilak bridge, Plaza cinema, Suvidha mall near Dadar Station, Kabutarkhana, Shivsenabhavan, and Shivaji Natya Mandir.
Figure 3: Google map of the proposed area showing vehicular movement pattern
Figure 4: Route map of bus route passing through proposed area
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2.1.2 Spatial or Attribute Data Collection
The comprehensive mobility plan of Municipal Corporation of Greater Mumbai (MCGM) was studied thoroughly. It is observed that pedestrian mode of transport is highly adopted as compared to public transport and integrated public transport. Private transportation mode is least used.
The difference in the number of public and private vehicles using the proposed area over approximately 10 years (2005 and 2014), as shown in Table 1, clearly indicates that there is 12 % increase in public transport, while above 100% increase in private transport.
Therefore, there is a need of diverting the human traf�ic to public transport. Table 1: BEST bus route survey
Bus No. Source Destination Frequency Journeytime (min)
4 Hutatama Chowk Oshiwara depot 45 21 40 P. ThakreUdyan Borivali station E 43 20 440 Wadala Depot Borivali station E 56 12 92 Anushakti Nagar World trade centre 27 31 521 Bandra RECL R C church 42 12 35 Marolmaroshi bus station Com P K Kurnechowk 29 18 39 Com P K KurneChowk Seepz bus station 29 29 51 SantaCruz depot Colaba Bus station 45 23 62 Central depot R/P Vidyavihar B. Station 22 32 200 Yari Rd Versova Shravan Y Rd 38 17 201 GoregoanB.station P.ThakreUdyan 51 14 241 Malvani depot Wadala depot 55 15 2 Colaba depot Agarkarchowk 42 14 33 PT. PlauskarChowk Goregoan bus station 41 15 37 J Mehta Marg Kurla station 75 10 86 Bandra depot Backbay depot 32 21
2.2 Analysis 2.3 Preparation of Maps
The existing distribution of the commuting population with The maps were prepared using QGIS. As it is open-source cross respect to mode of transportation shows that there is more load on platform and free application. It is faster than most of the software. It uses less time for processing because of the intern structure. The Keeping this factor in mind, the proposed modal share, as shown in study area was opened in Open-street map as shown in Figure 7(a). the pedestrian traf�ic (71%) as compared to public transport (16%). Fig. 6, has been worked out wherein more weight age is given to the use of public transport (39%).This way the commuting time will The existing attributes and land-use pattern were plotted by extracting data from OSM database as shown in Figure 7(b). generating good revenue. be reduced and public transport will be ef�iciently used thereby After running all the queries search and plotting features on Analysis of this collected data has been done using pie-chart. and plotted missing features manually as shown in Figure 7©. The Dadar western railway station is at 800m from the proposed metro map. A tour to the study area was done again to �ind missing features station thereby depicting the importance of the line connectivity, prepared map was taken to print composer and additional detailing metro (proposed) to railway (existing), and the inter modal as shown in Figure 7(d) was done. integration of the proposed metro station with buses, IPT and private pickups, and also the pedestrian traf�ic. 80 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Figure 5: Map showing land-use pattern
Table 2: Table showing variation in Modal share
Figure 6: Pie chart showing existing Modal Share
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Figure 7(a): Screenshot of QGIS showing study area Figure 7(b): Screenshot of queries searched to plot the map
Figure 7(c): Screenshot of study area map after plotting buildings
Figure 7(d): Map taken to print composer after plotting Land-use data
Figure 7(e): Final map showing existing land use pattern
82 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings 3. Results
The proposed Dadar metro station is an underground station located in a high development density zone. The existing land use pattern with the existing transportation facilities such as railways and road routes schools, hospitals, etc. Dadar western railway station is at 800m from the proposed metro station thereby depicting the importance of the line connectivity, metro (proposed) to railway (existing), and the
interThe modal existing integration distribution of the of proposed the commuting metro station population with buses,with respect IPT and to private mode ofpickups, transportation and also asthe shown pedestrian in Fig.6 traf�ic. shows that there is as shown in Fig. 08 has been worked out wherein more weight age is given to the use of public transport (39%). This way the commuting more load is on the pedestrian traf�ic (71%) as compared to public transport (16%). Keeping this factor in mind, the proposed modal share time will be reduced and public transport will be ef�iciently used thereby generating good revenue.
Figure 8: Pie chart showing proposed Modal Share
Figure 9: Proposed Concept plan
83 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Subway
been proposed as shown in the proposed plan, Fig.09, which will To minimize the traf�ic on the N C Kelkar road a Subway has connect Dadar western railway station to Dadar Metro Station and extended to the proposed basement parking lot planned below Shivaji Park. The subway will be 800 m in length, 6 m wide including pregnant women, physically challenged. The proposed Subway will 1 m horizontal escalator for the bene�it of the senior citizens, branch into 9 entry/exit points (e). As shown in Sheet 2 (proposed plan), ‘e1’ is the proposed entrance of basement parking, ‘e2’ is provided near Shivaji Park for basement parking, ‘e3’ opening is at Dr. Madhukar Raut Marg, ‘e4’ is at Dada sahib Rege Marg, ‘e5’ opening is near BS1, ‘e6’ is at Ram Maruti Marg, ‘e7’ is near IPT1, ‘e8’is near BS2, ‘e9’is near Plaza Cinema, and ‘e10’ is near BS3. Figure 9(b): Basement Parking
Bus Stop
For the convenience of the people, Bus stops ‘BS1’ and BS2’ have been proposed near Dadar Metro Station on N C Kelkar Road (BS1) and on Ranade Road (BS4) as shown in the Figure 9(c). As
per our �indings based on origin and destination survey, these stops walking time, Bus Stop ‘BS2’ is proposed. There is an existing bus have maximum routes. In order to minimise the traf�ic and reduce stop ‘BS3’. Bus bays have been proposed at nearby existing bus stops and proposed bus stops in order to avoid blocking of roads.
Figure 9(a): Subway connecting Dadar railway station and metro station
Basement Parking
Next, for the parking facilities, the basement parking for a capacity of 200 vehicles (two way stack) in an area of 4000 sq.m, i.e. Figure 9(c): Bus stops and IPTs 80m x 50m, approximately is proposed below existing Shivaji park area as shown in Fig.9(b), The design of the proposed parking area is based on the on-site vehicle parking count during peak hours, IPTs existing street parking, as per the National Building Code (NBC). The entrance ramp of the basement parking is proposed at ‘e1’ on congestion. Hence, authorised IPT parking stands have been Keluskar road and the exit at Shivaji Park Road No. 1 as shown in Due to the existing IPT parking there is increase in traf�ic proposed, as shown in Sheet 2. ‘IPT1’ is on N C Kelkar Road, Fig.9 (b). Two-wheeler parking has been proposed on adjacent to ‘IPT2’ is on extended Gokhale Road, and ‘IPT3’ is on Ranade Road. the Metro Station as shown in the Sheet 2.
84 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Bins provision of underground subway connecting the proposed metro station to Dadar western railway station, entry/exit to maximum In order to minimize littering, waste receptacles are provided at number of existing streets, bus stops, IPTs, and the proposed an interval of 20 m in the Subway as well as on the streets, making it highly visible. They are also provided near all bus stops, IPT stands, existing narrow footpaths. The other idea of providing huge basement parking which would avoid pedestrian traf�ic on the proposed basement parking and in the station box area. Drinking basement automated parking system below the existing Shivaji water facility is provided along with wash rooms at all Bus stops, park area will provide systematic control of the vehicles especially IPT stands, Basement parking and Station box area as shown in Sheet 2. the metro station, reducing on road or street parking, ease in during peak hours, ease in the traf�ic movement from and toward Street Furniture vehicular traf�ic diversions, and �inally less air pollution. Various street furniture has been proposed to create the setting 5. Conclusion for resting, sitting and eating, and social encounters with others. From the present study and the proposed work, it can be Seating facilities, such as benches, are proposed at every 50m to concluded that for a developing densely populated and crowded 60m, on heavy pedestrian use like retail shopping corridors, transit area like Dadar, the proposed concept plan for the proposed Dadar stops, plazas in order to integrate within the spaces where people underground metro station would provide a good solution to the wait, meet, or socialize along with the needs of the disabled and present transportation problems in this area and would provide senior citizens. To help people balance on steps and platforms a good line connectivity of the proposed metro station with the railings are provided along the edges of the station and staircases. existing modes of transportation with less disturbance to the For the physically challenged kerb ramps are proposed. For visually impaired people tactile paving, raised table-top crossings, auditory signals are to proposed to guide them without any trouble. Braille existing spatial pattern and traf�ic pattern. script also proposed in lifts, ticket counters, vending machines, References washrooms, etc.. Keeping in mind weather protected design, anti- 1. CED 46 (8068) WC Draft National Building Code of India. 2005. systems and sprinklers installation is proposed. For safety and skid pavement is proposed. For emergencies like �ire, �ire alarm security CCTV cameras and Emergency calling booth is proposed at 2. Comprehensive Mobility Plan (CMP) for Greater Mumbai. bus stops, IPT, railway station, and proposed metro station box area. Final Report Executive Summary. LEA Associates South Lighting is especially important at building entrances, intersections, Asia Pvt. Ltd. India. 2016. stairs, sudden changes in grade, dead ends, and remote walkways. LED bulbs, which can cut the energy consumption of lighting by 3. Data and Maps provided by MMRCL 40-70% can be used, thus making it sustainable. For ventilation air ducts are proposed over the proposed underground metro 4. Indian Road Congress (IRC). 69:1977. IRC 70:1977 and station roof. For checking of any threats security X-ray machines IRC 103:2012.
5. M. Hvidberg. Urban Land Use Mapping Using Register are proposed at all entries and exits. To guide traf�ic and mark Data and standard GIS. 2001. to be installed. For aesthetic look landscape on the road side and boundaries on the road, bollards and traf�ic barriers are proposed the medians is proposed. 6. Main Bill, Hannah Gail Greet. Site Furnishings: A Complete Guide to the Planning, Selection and Use of Landscape 4. Summary and Findings Furniture and Amenities. John Wiley & Sons. 2010;13-14.
The present study focused on the existing transportation 7. NZTA. Pedestrian planning and design guide. New Zealand available at the proposed metro station. After a rigorous spatial Transport Agency. 2009; Wellington. and non-spatial data collection of the proposed area in aspects of 8. PB Tamsekar, SB Thorat. Planning Support SYSTEM FOR better existing facilities, poorly designed existing transport routes, Urban and Regional Area Using GIS. traf�ic density, available modes of transportation, con�lict areas, a concept plan is designed and proposed for optimization and integration of the available modes of transportation in connection 9. Roy Chowdhury A, Bansal R. Bhat A. Gandhi S. On foot and with proposed metro station at Dadar, that leads to increasing the pedal, Down to Earth. 2012.
10. Shoujie Li, Meng Meng, Soi Hoi Lam and Yiik Diew userThe or commuter’smajor contribution ef�iciency. of the proposed study is the proposed Wong. Optimal Coordination Strategy for an Integrated
85 International Conference on BMCT Dubai 2021, April 06-08, Building Materials and Construction Technologies Conference Proceedings
Multimodal and Multi operator Transit System: Case of Websites and Mobile Applications Singapore. 2015;142(2):1. 1. Gökçen FirdevsYü cel. Chapter on Street Furniture and 11. Tao Zeng , Dawei Hu, Guolang Huang. 13th COTA Amenities: Designing the User-Oriented Urban Landscape. International Conference of Transportation Professionals. 2013. The Transportation Mode Distribution of Multimodal Transportation in Automotive Logistics. 2013;1.CICTP. 2. M-indicator, google app., public transport app, accessed for bus route no. and frequency. 12. Tejas Rawal, V Devadas, Nand Kumar. Conference Paper. Integrated Multi-modal Transportation in India. 2014. 3. Status paper on road safety in India. 2019.
13. Urban Street Design Guidelines. Pune Municipal 4. Corporation. Version I:2016. multimodal-integration-akshay-mani/ https://thecity�ix.com/blog/on-the-move-future-
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