Effect of reinforcement geometry on the performance of a reduced-scale strip footing model supported on geocell-reinforced sand

Authors

Department of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran

Abstract

Geocell is an effective type of geosynthetics for improving the performance of reinforced soil foundations due to provision of lateral confinement for the infill soil. In this research, in order to study the bearing pressure-settlement response of geocell reinforced sand, a reduced-scale physical model is developed and geocells with various geometrical dimensions (height, pocket size and width) produced from woven geotextile are used to reinforce sand bed. Strip footing model is then loaded monotonically to ultimate failure level and the influence of geocell geometrical properties on the improvement in bearing capacity and settlement of footing is described. The results show that by increasing height and decreasing pocket size of geocell, the beneficial effect of geocell reinforcement increases substantially. For the highest geocell used in the tests at settlement level of 6%, improvement in bearing capacity and percentage reduction in footing settlement is obtained as 2.1 and 48% respectively. The optimum width of geocell is determined five times the foundation width beyond which the improvement effect is negligible. It is also concluded that substituting a single layer of geocell reinforcement with 2 half-height and 4 quarter-height geocell layers results in 10% and 22% decrease in the ultimate bearing capacity respectively.

Keywords

References

References:
1. Zhang, L., Zhao, M., Shi, C. and Zhao, H. "Bearing capacity of geocell reinforcement in embankment engineering", Geotextiles and Geomembranes, 28(3), pp. 475-482 (2010).
2. Bathurst, R.J. and Karpurapu, R. "Large-scale triaxial compression testing of geocell-reinforced granular soils", Geotechnical Testing Journal, ASTM, 16(3), pp. 296-303 (1993).
3. Rajagopal, K., Krishnaswamy, N.R. and Madhavi Latha, G. "Behavior of sand confined with single and multiple geocells", Geotextiles and Geomembranes, 17(3), pp. 171-184 (1999).
4. Chen, R.H., Huang, Y.W. and Huang, F.C. "Confinement effect of geocells on sand samples under triaxial compression", Geotextiles and Geomembranes, 37, pp. 35-44 (2013).
5. Indraratna, B., Biabani, M. and Nimbalkar, S. "Behavior of geocell-reinforced subballast subjected to cyclic loading in plane-strain condition", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 141(1), pp. 1-16 http://dx.doi.org/10.1061/(ASCE) GT.1943-5606.0001199 (2015).
6. Madhavi Latha, G., Dash, S.K. and Rajagopal, K. "Numerical simulation of the behavior of geocell reinforced sand in foundations", International Journal of Geomechanics, ASCE, 9(4), pp. 143-152 (2009).
7. Dash, S.K., Rajagopal, K. and Krishnaswamy, N.R. "Strip footing on geocell reinforced sand beds with additional planar reinforcement", Geotextiles and Geomembranes, 19(8), pp. 529-538 (2001).
8. Dash, S.K., Sireesh, S. and Sitharam, T.G. "Model studies on circular footing supported on geocell reinforced sand underlain by soft clay", Geotextiles and Geomembranes, 21(4), pp. 197-219 (2003).
9. Sitharam, T.G. and Sireesh, S. "Behavior of embedded footings supported on geogrid cell reinforced foundation beds", Geotechnical Testing Journal, ASTM, 28(5), pp. 452-463 (2005).
10. Sitharam, T.G., Sireesh, S. and Dash, S.K. "Model studies of a circular footing supported on geocellreinforced clay", Canadian Geotechnical Journal, 42(2), pp. 693-703 (2005).
11. Madhavi Latha, G., Rajagopal, K. and Krishnaswamy, N.R. "Experimental and theoretical investigations on geocell-supported embankments", International Journal of Geomchanics, ASCE, 6(1), pp. 30-35 (2006).
12. Leshchinsky, B. and Ling, H.I. "Effects of geocell confinement on strength and deformation behavior of gravel", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 139(2), pp. 340-352 (2013).
13. Tanyu, B.F., Aydilek, A.H., Lau, A.W., Edil, T.B. and Benson, C.H. "Laboratory evaluation of geocell-reinforced gravel subbase over poor subgrades", Geosynthetics International, 20(2), pp. 47-61 (2013).
14. Moghaddas Tafreshi, S.N., Khalaj, O. and Dawson, A.R. "Repeated loading of soil containing granulated rubber and multiple geocell layers", Geotextiles and Geomembranes, 42(1), pp. 25-38 (2014).
15. Bathurst, R.J. and Jarret, P.M. "Large-scale model tests of geocomposite mattresses over peat subgrades", Transportation Research Record, 1188, pp. 28-36 (1988).
16. Dash, S.K., Krishnaswamy, N.R. and Rajagopal, K. "Bearing capacity of strip footings supported on geocell-reinforced sand", Geotextiles and Geomembranes, 19(4), pp. 235-256 (2001).
17. Sireesh, S., Sitharam, T.G. and Dash, S.K. "Bearing capacity of circular footing on geocell-sand mattress overlying clay bed with void", Geotextiles and Geomembranes, 27(2), pp. 89-98 (2009).
18. Madhavi Latha, G. and Somwanshi, A. "Effect of reinforcement form on the bearing capacity of square footings on sand", Geotextiles and Geomembranes, 27(4), pp. 409-422 (2009).
19. Moghaddas Tafreshi, S.N. and Dawson, A.R. "Comparison of bearing capacity of a strip footing on sand with geocell and with planar forms of geotextile reinforcement", Geotextiles and Geomembranes, 28(1), pp. 72-84 (2010).
20. Pokharel, S.K., Han, J., Leshchinsky, D., Parsons, R.L. and Halahmi, I. "Investigation of factors influencing behavior of single geocell-reinforced bases under static loading", Geotextiles and Geomembranes, 28(6), pp. 570-578 (2010).
21. Dash, S.K. "Influence of relative density of soil on performance of geocell-reinforced sand foundations", Journal of Materials in Civil Engineering, ASCE, 22(5), pp. 553-538 (2010).
22. Dash, S.K. "Effect of geocell type on load carrying mechanism of geocell reinforced sand foundations", International Journal of Geomechanics, ASCE, 12(5), pp. 537-548 (2012).
23. Biswas ,A., Murali Krishna, A. and Dash, S.K. "Influence of subgrade strength on the performance of geocell-reinforced foundation systems", Geosynthetics International, 20(6), pp. 376-388 (2013).
24. Mitchell, J.K., Kao, T.C. and Kavazanjian, E. "Analysis of grid cell reinforced pavement bases", Technical Report GL-79-8, Department of Civil Engineering, University of California, Berkeley, CA (1979).
25. Avesani Neto, J.O., Bueno, B.S. and Futai, M.M. "A bearing capacity calculation method for soil reinforced with a geocell", Geosynthetics International, 20(3) pp. 129-142 (2013).
26. Moghaddas Tafreshi, S.N., Shaghaghi, T., Tavakoli Mehrjardi, GH., Dawson, A.R. and Ghadrdan, M. "A simplified method for predicting the settlement of circular footings on multi layered geocell-reinforced non-cohesive soils", Geotextiles and Geomembranes, 43(4), pp. 332-344 (2015).
27. Kargar, M. and Mir Mohammad Hosseini, S.M. "Earth pressure distribution behind rigid non-yielding walls under the effect of repeated loading on backfill", Arabian Journal of Geosciences, 8(2), pp. 839-847 (2015).
28. Moghaddas Tafreshi, S.N. and Dawson, A.R. "A comparison of static and cyclic loading responses of foundations on geocell-reinforced sand", Geotextiles and Geomembranes, 32(5), pp. 55-68 (2012).
29. Dash, S.K., Rajagopal, K. and Krishnaswamy, N.R. "Behavior of geocell-reinforced sand beds under strip loading", Canadian Geotechnical Journal, 44(7), pp. 905-916 (2007).
30. Gurbuz, A. and Mertol, H.C. "Interaction between assembled 3-D honeycomb cells produced from high density polyethylene and a cohesionless soil", Journal of Reinforced Plastics and Composites, 31(12), pp. 828-836 (2012).
31. Fakher, A. and Jones, C. "Discussion on bearing capacity of rectangular footings on geogrid-reinforced sand, by Yetimoglu T., Wu, J.T.H., Saglamer, A.,1994", Journal of Geotechnical Engineering, ASCE, 122(4), pp. 326-327 (1996).
32. Viswanadham, B.V.S. and Konig, D. "Studies on scaling and instrumentation of a geogrid", Geotextiles and Geomembranes, 22(5), pp. 307-328 (2004).
Scientia Iranica
Volume 24, Issue 1 - Serial Number 1
Transactions on Civil Engineering (A)
January and February 2017
Pages 96-109

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