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Home , Geotextile, Soil compaction

d 2n International Conference on New Developments in Mechanics and , 28-30 May 2009, Near East University, Nicosia, North Cyprus

Effect of on the compaction properties of

S. Nilay Keskin P rof. PhD., Süleyman Demirel University, Faculty of Engineering-Architecture, Department of Civil E ngineering, Isparta, 32260, Turkey.

Ömür Çimen T.Selçuk Göksan Soner Uzundurukan A ssist. Prof. PhD., Süleyman Demirel University, Faculty of Engineering-Architecture, Department of , Isparta, 32260, Turkey. Mehmet Karpuzcu M s. Of Science, Civil Engineer, Isparta, 32260, Turkey

KEYWORDS: , Compaction, , , Pumice.

ABSTRACT: In order to improve the engineering characteristic of the soil, several methods have been applied such as compressing the soil, using supplementary materials, carrying out thermo operations and using geotextile. Nowadays, usage of geotextiles in stabilization of the soil is increasing gradually. The geotextile products used for different purposes in soil and engineering are produced in a great variety. In this study, the effects of woven and non-woven geotextiles on the compaction parameters of sand, clay and pumice were investigated. For this aim, compaction tests were conducted on sand, clay and pumice specimens. Compaction tests were also conducted on the specimens that were reinforced with one layer of geotextile and reinforced with two layers of geotextiles respectively. And results obtained from these tests were compared. No significantly effect was observed of geotextile reinforcement of pumice on the quality of compaction. Maximum dry density and optimum values of clayey soil were obtained on the experiments that were conducted on the clayey soil reinforced with one layer of propex 6062 (woven).

1 INTRODUCTION

Geosynthetics are relatively thin, flexible polymeric materials. Over the past decades there has been a tremendous increase in their use due to development a large range of new materials. When these materials are used in soil, they improve its engineering performance and lower cost of (Giraud, 1986; Bell, 1993). term is the general name and it involves geotextiles, geomembrans, , geonets, geomats and geocomposites. These materials perform a number of basic functions in soil stabilization, namely, reinforcement, separation, filtration, , cushioning and isolation. Most widely used materials in producing of geosynthetics are polyamide, polypropylene, , polyethylene, polyvinylidene chloride, mineral and carbon fibers. Two main types of geosynthetics are used in geotechnical engineering: that is woven and non-woven geosynthetics (Çoruh, 1991; Bell,1993; Frost ve Han, 1999). Geosynthetic clay liners are a manufactured product that consist of a thin layer of bentonite that may be encapsulated between two geotextiles and held together by needle punching combined with thermal bonding ( Rowe et al., 2004). Geosynthetic clay liners have been employed as barriers in , recent times have seen an increase in the variety of their applications. The capacity of geosynthetic clay liners to attenuate metals and metalloids (As, Al, Cd, Cu, Fe, mn, Ni, Sr, Zn) from mine acidic rock drainage water and a neutral-PH, As-rich water associated with gold

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d 2n International Conference on New Developments in and Geotechnical Engineering, 28-30 May 2009, Near East University, Nicosia, North Cyprus

mine tailings was evaluated. These minerals were responsible for retention of metals in addition to the cation exchange of the Geosynthetic clay liners ( Lange et al., 2007). Smith and Filz (2007), showed axisymmetric analyses of layers of geosynthetic reinforcement. They said axisymmetric analyses also produced good agreement with three-dimensional analyses for an example column-supported geosynthetic-reinforced . Bozbey and Güler (2006), investigated the feasibility of using a silty soil excavated in highway construction as liner material. They used different levels of compaction energy. They implied higher compaction efforts did not result in lower hydraulic conductivities in field scales. Güler et al. (2007) studied numerical analysis of reinforced soil- structures with cohesive and granular backfills. They implied under working loads the potential failure surface used in current design analysis is correct, but the failure plane of a geosynthetic-reinforced soil-retaining wall at failure approaches a direct sliding type or a bilinear plane, which starts from the toe of the wall with a very shallow slope. In this study, the effects of woven and non-woven geotextiles on the compaction parameters of sand, clay and pumice were investigated. For this aim, compaction tests were conducted on sand, clay and pumice specimens. Then, compaction tests also conducted on the specimens that were reinforced with one layer of geotextile and reinforced with two layers of geotextile. And results obtained from these tests were compared.

2 MATERIAL VE METHOD

2.1 Material

In the experimental study, three different type of materials (clay, sand and pumice) were used as control group. Clay sample obtained from Eskişehir region and sand sample obtained from Antalya- Belek region. Pulverized pumice sample was taken from Isparta Isbaş A.Ş. Classification tests were carried out on these samples, and the results of these tests are given in Table1.

Table 1. Engineering properties of soils used Index Properties Sand Pumice Clay Specific Gravity Gs 2.65 2.38 2.62 Effective Particle Size; D10 (mm) 0.05 0.03 - Average Particle Diameter; D 50 0.098 0.53 0.002 (mm) Uniformity Coefficient ; CU 2.4 26.6 - Coefficient of Curvature; CC 1.01 1.83 - Liquid Limit; wL (%) - - 54 Plastic Limit; wP (%) - - 24.5 Plasticity Index; PI (%) - - 29.5 Shrinkage Limit; wR (%) - - 19 ; e (%) 75 79 65 SM Pumice CH

Compaction tests were applied on both control group and samples prepared by placing several layer of geotextiles in between. In these tests two different type of geotextiles were used. One of thegeotextile was propex 6062 woven type geotextile manufactured by Amoca and the other was geo 400 non-woven type geotextile manufactured by Hassan. The mechanical properties of geotextiles given from the manufacturers are specified in Table 2 and 3.

421 Effect of geotextiles on the compaction properties of soils Keskin, S. N., Çimen, Ö., Göksan, T.S., Uzundurukan, S. & Karpuzcu, M.

Table 2. Engineering properties of geo 400 Tensile Elongation at Puncture Breaking Properties Weight Strength Break Strength Strength Unit gr/cm2 N/5 cm % N N ASTM-D ASTM-D ASTM-D Test Method DIN 53854 ASTM-D 751 4632 4632 1117 Geo 400 400 1400 210 1055 245 Raw materials: Polyester and/or Polypropylene

Table 3. Engineering properties of propex 6062 UV Tensile Puncture Elongation at Resistance at Properties Weight Strength Strength Break retained at 500 hrs Unit gr/cm2 N N % % ASTM- Test Method DIN 53854 DIN 53858 DIN 54307 DIN 53857 D4355 Propex 6062 190 1200 4800 17 >90 Raw materials: Polypropylene

2.2. Compaction Tests

In order to investigate the effect of geotextile on , standard proctor tests were performed on sand, clay and pumice. Firstly, maximum dry density and optimum water content values of each sample were determined without geotextile. Then, compaction tests were conducted on the soils reinforced with one and two layers of geotextile. The geotextile layers were placed into the specimens as shown in Figure 1.

Geotextile Geotextile

H/3 H/2

H H/3

H/2 H/3

D D D a b c

Figure1. Placement of geotextile layers into the compaction mold

In Figure 1, a represents the tests without geotextile, b represents the placement of one layer of geotextile in the compaction mold and c represents the placement of one layer of geotextile in the compaction mold. In standard proctor test, soil was compacted in three equal layers into the mold by a rammer consisting of a 2.5 kg mass falling freely through 305 mm. 25 blows of rammer were applied onto each layer. In the compaction tests represented in Figure 1b, geotextile layer was placed on the half height of the compaction mold. In that, same blows of rammer were used. In the compaction tests shown in Figure 1c, the first soil layer was compacted, then a geotextile layer was placed on this soil layer. Required amount of soil was placed in the mold and the second layer was compacted. Then the

422 d 2n International Conference on New Developments in Soil Mechanics and Geotechnical Engineering, 28-30 May 2009, Near East University, Nicosia, North Cyprus

second geotextile layer was placed on the second soil layer. Finally, third soil layer was compacted and tests were completed.

3. RESULTS AND DISCUSSIONS

In this study, the effects of geotextile usege on the compaction parameters of three different materials (sand, clay and pumice) were investigated. The results of compaction tests are given in Table 4. In Table 4, w represents optimum water content and represents maximum dry opt  k max density.

Table 4. Compaction test results (Karpuzcu, 2001) Soil type Sand Pumice Clay Test type a b c b c a b c b c a b c b c

Geotextile - - - type Geo 400 Geo 400 Geo 400 Geo 400 Geo 400 Geo 400 Propex 6062 Propex 6062 Propex 6062 Propex 6062 Propex 6062 Propex 6062

wopt (%) 18 14.7 14.6 14 14 22.5 28 30 27 27 24 21 20 16 16 (gr/cm3)  k max 1.51 1.62 1.59 1.59 1.57 1.33 1.29 1. 27 1.33 1.30 1.58 1.58 1.54 1.62 1.61 a: Without reinforcement b: Reinforced with one layer of geotextile c: Reinforced with two layers of geotextile

As can be seen from the test results, better performance for maximum dry density value and better performance were observed in sandy soil non-woven and clayey soil woven geotextile, respectively.. No effect of reinforcement with woven geotextile on maximum dry density was observed in pumice, whereas non-woven geotextile usage caused to decrease of maximum dry density value of pumice. This situation can be explained with high permeability of pumice and high energy losses due to elasticity of non-woven geotextile. Optimum water content values decreased with geotextile reinforcement on clay and sand. As the layer of geotextile layers were increased, so did the decrease in optimum water content. Optimum water content was observed to increase in geotextile layered pumice samples compared to control samples. It was observed that, Propex 6062 caused larger energy losses in sand but geo 400 caused larger energy losses in clay.

4. CONCLUSIONS

In this research, to investigate the effects of geotextile use on the compaction parameters of soils, a series of compaction tests were applied. Non-woven (geo 400) and woven (propex 6062) geotextiles were used in the compaction tests that were conducted on sand, clay and pumice materials. It was observed from the results that non-woven and woven geotextile usage was more convenient for sand and clay, respectively. Larger dry density values were obtained from the tests on the soils reinforced with one layer of geotextile. As the number of geotextile layer increase, the energy losses due from elasticity of geotextile also increase.

REFERENCES

Bell, F.G. (1993).Engineering Treatment of Soils. E&FN Spon. Bozbey, I., Güler, E. (2006). Laboratory and field testing for utilization of an excavated soil as material, Waste Management, 26, 1277-1286. Çoruh, T. (1991). Geosynthetics, DSİ General Directorate Technical Research and Quality Control Department Presidency, Publication Number: Mlz.798, 176pp, Ankara, (in Turkish).

423 Effect of geotextiles on the compaction properties of soils Keskin, S. N., Çimen, Ö., Göksan, T.S., Uzundurukan, S. & Karpuzcu, M.

Giraud, J.P. (1986). From geotextiles to geosynthetics: a revolution in geotechnical engineering. Proc. 3rd International Conf. on Geotextiles, Vienna, Vol 1, pp.1-18. Güler, E., Hamderi, M, Demirkan, M.M. (2007). Numerical analysis of reinforced soil-retaining wall structures with cohesive and granular backfills, 14, 6, 330-345. Karpuzcu, M. (2001). Geotextile Reinforcement Soils and Soil Stabilization, SDÜ Science Institute, Ms. Thesis, (in Turkish). Lange,K., Rowe, R.K., Jamieson, H. (2007). Metal retention in geosynthetics clay liners following permeation by different mining solutions, Geosynthetics International, 14, No. 3, 178-187. Smith, M., Filz, G. (2007). Axisymmetric numerical modelling of a unit cell in geosynthetic reinforced, column-supported embankments, Geosynthetics International, 14, No. 1, 13-32. Rowe, R.K., Quigley, R.M., Brachman, R.W.I., Booker, J.R. (2004). Barrier systems for waste disposal facilities, Taylor & Fransis Books Ltd.Spon Press, 560pp.

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