Mechanically Stabilized Earth (MSE)
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An Experimental Study of a Nailed Soil Slope: Effects of Surcharge Loading and Nails Characteristics
applied sciences Article An Experimental Study of a Nailed Soil Slope: Effects of Surcharge Loading and Nails Characteristics Mahmoud H. Mohamed 1 , Mohd Ahmed 1,*, Javed Mallick 1 and Pham V. Hoa 2 1 Civil Engineeg Department, College of Engineering, K. K. University, Abha 61421, Saudi Arabia; [email protected] (M.H.M.); [email protected] (J.M.) 2 Ho Chi Minh City Institute, Vietnam Academy of Science and Technology, Ho Chi Minh City 008428, Vietnam; [email protected] * Correspondence: [email protected]; Tel.: +966-172-418-439 Abstract: The earth nailing system is a ground improvement technique used to stabilize earth slopes. The behavior of the earth nailing system is dependent on soil and nailing characteristics, such as the spacing between nails, the orientation, length, and method of installation of nails, soil properties, slope height and angle, and surcharge loading, among others. In the present study, a three-dimensional physical model was built to simulate a soil nailed slope with a model scale of 1:10 with various soil nail characteristics. The simulated models consist of Perspex strips as facing and steel bars as a reinforcing system to stabilize the soil slope. Sand beds in the model were formed, using a sand raining system. The performance of nailed soil slope models under three important nails characteristics, i.e., length, spacing and orientation, with varying surcharge loading were studied. It was observed that there is a reduction in the lateral movement of slope and footing settlements with an increase in length. It was found that the slope face horizontal pressure is non-linear with different nail characteristics. -
Use of GEOGRID for Strengthening and Reducing the Roadway Structural Sections
NDOT Research Report Report No. 327-12-803 Use of GEOGRID for Strengthening and Reducing the Roadway Structural Sections January 2016 Nevada Department of Transportation 1263 South Stewart Street Carson City, NV 89712 Disclaimer This work was sponsored by the Nevada Department of Transportation. The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the State of Nevada at the time of publication. This report does not constitute a standard, specification, or regulation. USE OF GEOGRID FOR STRENGTHENING AND REDUCING THE ROADWAY STRUCTURAL SECTIONS Final Report Submitted to Nevada Department of Transportation Nader Ghafoori, Ph.D., P.E. Professor of Civil Engineering AND MohammadReza Sharbaf Graduate Research Assistant Department of Civil and Environmental Engineering and Construction University of Nevada Las Vegas 4505 Maryland Parkway Box 454015 Las Vegas, NV 89154-4015 Tel: (702) 895-2531 Fax: (702)895-3936 Email: [email protected] January 2016 ABSTRACT An experimental laboratory program to assess the effectiveness of biaxial and triaxial geogrid-reinforced flexible pavements to reduce roadway section was carried out. Six laboratory tests were conducted using a steel cylindrical mold with dimensions of 1.8 m (6 ft) in diameter and 2.1 m (7 ft) in height. The studied reinforced and unreinforced (without geogrid) sections consisted of a locally-obtained subgrade with a minimum thickness of 1.5 m (5 ft) and an asphaltic surface course of 7.6 cm (3 in). -
Stiffness and Strength Improvement of Geosynthetic-Reinforced Pavement
infrastructures Article Stiffness and Strength Improvement of Geosynthetic-Reinforced Pavement Foundation Using Large-Scale Wheel Test Jason Wright 1, S. Sonny Kim 2,* and Bumjoo Kim 3 1 Aviation Engineer II, Pond and Company, Peachtree Corners, GA 30092, USA; [email protected] 2 Civil Engineering, College of Engineering, University of Georgia, Athens, GA 30602, USA 3 Department of Civil and Environment Engineering, Dongguk University, Seoul 04620, Korea; [email protected] * Correspondence: [email protected] Received: 2 March 2020; Accepted: 1 April 2020; Published: 3 April 2020 Abstract: Laboratory cyclic plate load tests are commonly used in the assessment of geosynthetic performance in pavement applications due to the repeatability of testing results and the smaller required testing areas than traditional Accelerated Pavement Testing facilities. While the objective of traditional plate load testing procedure is to closely replicate traffic conditions, the reality is that rolling wheel loads produce different stresses in pavement layers than traditional cyclic plate load tests. This two-fold study investigates the differences between the stress response of subgrade soil from a rolling wheel load (replicating rolling traffic conditions) and a unidirectional dynamic load (replicating traditional plate load test procedures) in order to obtain a more realistic stress response of pavement layers from rolling wheel traffic. Ultimately, results show that the testing specimens that experienced rolling wheel loading had an average of 17% higher pressure measurements in the top of the subgrade than vertically loaded (unidirectional dynamic load) specimens. The second segment of this study is used in conjunction with the first to analyze aggregate base material behavior when using a geosynthetic for reinforcement. -
A Qljarter Century of Geotechnical Researcll
A QlJarter Century of Geotechnical Researcll PUBLICATION NO. FHWA-RD-98-139 FEBRUARY 1999 1111111111111111111111111111111 PB99-147365 \c-c.J/t).:.. L~.i' . u.s. D~~~~~~~Co~~~~~erce~ Natronal_Tec~nical Information Service u.s. DepartillCi"li of Transportation Spnngfleld, Virginia 22161 Research, Development & Technology Turner-Fairbank Highway Research Center 6300 Georgetown Pike McLean, VA 22101-2296 FOREWORD This report summarizes Federal Highway Administration (FHW!\) geotechnical research and development activities during the past 25 years. The report incl!Jde~: significant accomplishments in the areas of bridge foundations, ground improvenl::::nt, and soil and rock behavior. A fourth category included important miscellaneous efrorts tl'12t did not fit the areas mentioned. The report vlill be useful to re~earchers and praGtitior,c:;rs in geotechnology. --------:"--; /~ /1 I~t(./l- /-~~:r\ .. T. Paul Teng (j Director, Office of Infrastructure Research, Development. and Technologv NOTiCE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States G~)\fernm8nt assumes no liahillty for its contt?!nts or use thereof. Thir. report dor~s not constiil)tl":: a standard, specification, or regu!p,tion. The; United States Government does not endorse products or n18;1ufaGturers, Traderrlc,rks or nianufacturers' narl1es appear in thi;-, report only bec:8'I)Se they arc considered essential to tile object of the document. Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. FHWA-RD-98-139 4. Title and Subtitle 5. Report Date A Quarter Century of Geotechnical Research February 1999 6. Performing Organization Code ). -
Stability Analysis of Slope Under Different Soil Nailing Parameters Based on the Geostudio
International Journal of IJGE 2015 1(2): 88-92 Geohazards and Environmen t http://ijge.camdemia.ca, [email protected] Available at http://ojs.library.dal.ca/ijge Technical Notes Stability Analysis of Slope under Different Soil Nailing Parameters Based on the GeoStudio Ou-Ling Tang* and Qing-Ming Jiang Chengdu University of Technology, Chengdu 610059, P.R. China Abstract: In order to investigate the influence of different soil nailing parameters on the safety factor of a slope, the slope stability is analyzed by the GeoStudio software with different analysis methods. Soil nailing parameters (such as nail inclination, nail horizontal space, nail diameter and length) that influence the slope stability are analyzed by the Morgenstern-Price method. As the results show, the slope has the highest safety factor when the obliquity of soil nailing is about 15°, the safety factor decreases with the increase of soil-nail horizontal space with an evident acceptable space range of 2 m or less and increases linearly with the increase of soil-nail diameter and length. However when the soil- nail length equals approximately the height of the slope, the safety factor increases slowly. These results can provide a design base for field engineers. Keywords : soil nailing, retaining parameter, safety factor, Morgenstern-Price method 1 Introduction used the FLAC to simulate the change of nail’s Soil nailing is a technique of in-situ ground length, inclination, assigned the way and soil reinforcement which is widely used in the layer parameter to the influence of the horizontal foundations, pit excavations and permanent displacement of foundation pit and the greatest Sun (2007) discussed slopes. -
Green Terramesh Rock Fall Protection Bund
Double Twist Mesh Project: 112 Bridle Path Road Date: May 2016 Client: Private Residence, Heathcote Valley Designer: Engeo Consulting Ltd Contractor: Higgins Contractors Location: Christchurch Green Terramesh Rock Fall Protection Bund The 22 February 2010 Christchurch earthquake triggered numerous rock falls causing damage to homes built close to cliffs. Many of those that survived were red zoned by the Government due of the risk of further rock fall or cliff collapse. The area around Heathcote Valley and in particular Bridle Path road was identified as an area of high risk requiring some form of rock fall protection structure to be constructed in order to protect dwellings from rock fall in the event of any further earthquakes. Geofabrics offers a range of solutions that includes certified catch fences and Green Terramesh rockfall embankments. A rockfall embankment was the preferred solution for this site which has the potential to experience multiple rock fall events. The use of Green Site Preparation Terramesh allows the embankment slopes to be steepened and the footprint reduced to form a stable and robust bund having high energy absorption characteristics. The structure is typically filled with compacted granular material or engineered soil fill with horizontal soil reinforcement (geogrid or DT mesh) inclusions. The front face can either be vegetated or finished with a rock veneer. Rockfall embankments have undergone extensive full scale testing in Europe. Actual rock impacts in excess of 5000kJ into Green Terramesh rockfall embankments located in Northern Italy have been back-analysed and the design methodology verified using numerical modelling (FEM) techniques. This research has resulted in the development of design charts to provide designers with a Bund Design simplified design method based on rock penetration depth. -
Coming Full Circle 32 30 Years of Launched Soil Nails 48 Ground Stabilization for Underground Construc
20 Ground Improvement 32 30 years of 48 Ground stabilization for 72 The Rise of UAVs – Coming Full Circle Launched Soil Nails Underground Construction in Geotechnics SEPTEMBER // OCTOBER 2016 Ground Improvement Proudly published by the Geo-Institute of ASCE SEPT/OCT GROUND 2016 IMPROVEMENT THE EVOLUTION OF LAUNCHED SOIL NAILS A 30-Year Retrospective By Colby Barrett, JD, PE, M.ASCE, and Graeme Quickfall Fiberglass launched soil nails used for bluff stabilization in Northern California. 32 GEOSTRATA SEPTEMBER/OCTOBER 2016 aunched soil nails are a unique remedial technology in the geotechnical construction Ltoolbox. These 20-ft-long, 1.5-in.-diameter nails are installed in a single shot using a compressed air “cannon” at velocities of up to 250 miles/hour, and at rates approaching 250 nails/day. The nails reinforce an unstable or potentially unstable soil mass by transferring the nail’s tensile and shear capacity into the sliding soil. However, at least as interesting as the tool itself, is the story behind the development of launched soil nail technology over the past 30 years. This story is not just one of technological innovation, advance- ment, and refinement of a specific piece of construction equipment. It stands as a testament of the innovative, bold, and resourceful char- acter of engineers and practitioners in the geotechnical construction industry. It’s also an insight into how engineers from three continents — often working independently — responded to challenges as diverse as national tragedy, shrinking infrastructure budgets, and the challenges posed by geohazards across the globe, to create a powerful new tool that continues to be refined, updated, and improved to the present day. -
Geosynthetic Reinforced Steep Slopes: Current Technology in the United States
applied sciences Review Geosynthetic Reinforced Steep Slopes: Current Technology in the United States Yoo-Jae Kim 1,*, Ashley Russell Kotwal 1, Bum-Yean Cho 2, James Wilde 1 and Byung Hee You 1 1 Department of Engineering Technology, Materials Science, Engineering, and Commercialization Program, Texas State University, 601 University Drive, San Marcos, TX 78666, USA; [email protected] (A.R.K.); [email protected] (J.W.); [email protected] (B.H.Y.) 2 Department of Fire Safety Research, Korea Institute of Civil Engineering and Building Technology, 64 Ma-doro 182beon-gil, Mado-myeon, Hwaseong-si, Gyeonggi-do 18544, Korea; [email protected] * Correspondence: [email protected]; Tel.: +1-512-245-6309 Received: 5 April 2019; Accepted: 13 May 2019; Published: 16 May 2019 Abstract: Geosynthetics is a crucial mechanism in which the earth structures can be mechanically stabilized through strength enforcing tensile reinforcement. Moreover, geosynthetic reinforcement stabilizes steep slopes through incorporating the polymeric materials, becoming one of the most cost-effective methods in not only accommodating budgetary restrictions but also alleviating space constraints. In order to explicate on the applicability and widen the understanding of geosynthetic reinforcement technology, a synthesis study was conducted on geosynthetic reinforced steep slope. This study is very important because in not only highlighting the advantages and limitations of using geosynthetic reinforcement but also in investigating the current construction and design methods with a view to determining which best practices can be employed. Furthermore, this study also identified and assessed the optimal condition of the soil, performance measures, construction specifications, design criteria, and geometry of the slope. -
Slope Stabilization and Repair Solutions for Local Government Engineers
Slope Stabilization and Repair Solutions for Local Government Engineers David Saftner, Principal Investigator Department of Civil Engineering University of Minnesota Duluth June 2017 Research Project Final Report 2017-17 • mndot.gov/research To request this document in an alternative format, such as braille or large print, call 651-366-4718 or 1- 800-657-3774 (Greater Minnesota) or email your request to [email protected]. Please request at least one week in advance. Technical Report Documentation Page 1. Report No. 2. 3. Recipients Accession No. MN/RC 2017-17 4. Title and Subtitle 5. Report Date Slope Stabilization and Repair Solutions for Local Government June 2017 Engineers 6. 7. Author(s) 8. Performing Organization Report No. David Saftner, Carlos Carranza-Torres, and Mitchell Nelson 9. Performing Organization Name and Address 10. Project/Task/Work Unit No. Department of Civil Engineering CTS #2016011 University of Minnesota Duluth 11. Contract (C) or Grant (G) No. 1405 University Dr. (c) 99008 (wo) 190 Duluth, MN 55812 12. Sponsoring Organization Name and Address 13. Type of Report and Period Covered Minnesota Local Road Research Board Final Report Minnesota Department of Transportation Research Services & Library 14. Sponsoring Agency Code 395 John Ireland Boulevard, MS 330 St. Paul, Minnesota 55155-1899 15. Supplementary Notes http:// mndot.gov/research/reports/2017/201717.pdf 16. Abstract (Limit: 250 words) The purpose of this project is to create a user-friendly guide focusing on locally maintained slopes requiring reoccurring maintenance in Minnesota. This study addresses the need to provide a consistent, logical approach to slope stabilization that is founded in geotechnical research and experience and applies to common slope failures. -
STUDY on SLOPE STABILIZATION by SOIL NAILING Project Report Submitted in Partial Fulfillment for the Degree of Bachelor of Technology in Civil Engineering
STUDY ON SLOPE STABILIZATION BY SOIL NAILING Project Report submitted in partial fulfillment for the degree of Bachelor of Technology in Civil Engineering under the supervision of : Mr.Saurabh Rawat by Tushar Soni (111676) Sachin goyal (111696) to Jaypee University of Information and Technology Waknaghat, Solan – 173234, Himachal Pradesh May, 2015 Certificate This is to certify that project report entitled “ Study on slope stabilization by soil nailing and stability analysis using geo5 software”,submitted by Sachin Goyal and Tushar Soni in partial fulfillment for the award of degree of Bachelor of Technology in Civil Engineering to Jaypee University of Information Technology, Waknaghat, Solan has been carried out under my supervision.This work has not been submitted partially or fully to any other University or Institute for the award of this or any other degree or diploma. Signature of Supervisor Dr. Ashok Kumar Gupta Mr. Saurabh Rawat Head Of Department Date : External Examiner 1 Acknowledgement I thankfully acknowledge the contribution of various different journals and books, from which some of the material have been collected to enrich this project. I am very much grateful to Mr. Saurabh Rawat ,for his guidance and support throughout my project,and also for his constant inspiration from the very first day when I had started the work for this project. I would also like to give my deepest and sincerest thanks to my friends for guiding me and improving my project. Date: Sachin Goyal (111696) Tushar Soni (111676) 2 ABSTRACT Since its development in Europe in the early 1970s, soil nailing has become a widely accepted method of providing temporary and permanent earth support, underpinning and slope stabilization on many civil projects in the United States. -
Strataweb® 356 Product Data
StrataWeb® 356 Product Data STRATAWEB® is a high performance three dimensional cellular confinement system. Filled with granular material, StrataWeb provides superior confinement and reinforcement for load support, erosion control, and slope renforcement applications. StrataWeb is manufactured from extruded strips of HDPE that are precision welded to form multiple cell heights and sizes. Sections consist of 58 strips of HDPE, resulting in sections of 29 cells long and 10 cells wide. If perforations are required then 11% ± 2%, and up to 16% ± 3%, of the cell wall is removed. MATERIAL PROPERTIES TEST METHOD UNIT TEST VALUE 3 3 Polymer Density ASTM D 1505 g/cm (lb/ft ) 0.935-0.965 (58.4-60.2) Environmental Stress Crack Resistance ASTM D 5397 hours >400 Carbon Black Content ASTM D 1603 % by weight 1.5% minimum Nominal Sheet Thickness after texturing ASTM D 5199 mm (mil) 1.52 (60) -5%, +10% Polyethylene strip shall be textured with a multitude of rhomboidal (diamond shape) indentations. The rhomboidal indentations shall have a surface density of 22 to 31 per cm2 (140 to 200 per in2). PHYSICAL PROPERTIES UNIT TYPICAL VALUE Nominal-Expanded Cell Size mm (in) 259 (10.2) x 224 (8.8) (width x length) Nominal-Expanded Cell Area cm2 (in2) 289 (44.8) Nominal-Expanded Section m (ft) 2.56 (8.4) x 6.52 (21.4) (width x length) Nominal-Expanded Section Area 2 2 m (ft ) 16.7 (180) (width x length) Cell Depth mm (in) 75 (3) 100 (4) 150 (6) 200 (8) Seam Peel Strength1 N (lbs) 1065 (240) 1420 (320) 2130 (480) 2840 (640) Section Weight kg (lbs) 19.5 (43) 25.9 (57) 39 (86) 51.7 (114) Sections per Pallet -- 60 50 30 25 A 102mm (4in) weld joint supporting a load of 72.5 kg (160 lbs) for 30 days minimum or a 102mm (4in) weld joint supporting a load of 72.5 kg (160 lbs) Seam Hang Strength -- for 7 days minimum while undergoing temperature change from 23°C (74°F) to 54°C (130°F) on a 1 hour cycle. -
Terram™ Geocell
TERRAM™ GEOCELL www.terram.com TERRAM™ GEOCELL A lightweight, permeable Geocell that is easy to install and allows free flow 3 of water, whilst offering cost savings. TERRAM GEOCELL - The Product TERRAM - The Brand TERRAM GEOCELL is a 3D cellular confinement system. TERRAM branded products are manufactured by PGI, a leading Manufactured from permeable geotextile fabric, TERRAM GEOCELL global innovator and manufacturer of specialty materials, and the is expanded on-site to form a honeycomb-like structure which can largest global manufacturer of nonwovens. be filled with sand, soil or other site material. The innovative TERRAM product range includes geotextiles, geocells, This cost effective solution has multiple applications enabling geocomposites, cable and pipeline protection, ground reinforcement reduced projects costs and lower environmental impact. mesh. With over 45 years’ experience in the geosynthetic market, TERRAM provides value engineered solutions for the construction of highways, railways, landfill, pipelines and landscapes. Typical Applications • Soil Stabilisation • Retaining Walls TERRAM has over 15 years • Slope Erosion Control experience manufacturing cellular • Load Platforms confinement systems and has • Tree Root Protection developed a market leading • Flood Defence multifunctional product. Tree Roots Protection Protect tree roots from vehicle traffic, whilst maintaining water and nutrient absorption using TERRAM GEOCELL. Using TERRAM GEOCELL for tree root protection ensures the WHY TERRAM GEOCELL? Typical Profile roots beneath are protected from vehicle loads by confining the sub-base and stabilising the ground. When the permeable • Lightweight and easy to handle reducing installation costs. TERRAM GEOCELL is filed with a porous, no fines, free-flowing TERRAM GEOCELL filled • Permeable geotextile allows free flow of water, essential with angular, reduced-fines aggregate the system allows essential passage of air and water in tree root applications.