Counterface soil type and loading condition effects on granular/cohesive soil – Geofoam interface shear behavior

Abstract

Soil – geofoam interfaces have been studied through an extensive experimental program by performing multiple series of interface shear tests using two different granular soils (i.e. beach sand and construction material sand) and one cohesive soil (i.e. bentonite clay) as well as a soil mixture containing 75% sand and 25% clay by dry weight at distinct loading conditions (i.e. normal stresses (σ): 25, 100, 250; low, moderate, high loading conditions, respectively). Using the shear stress versus horizontal displacement curves obtained, some important engineering design parameters including peak shear stress, residual shear stress, interface sensitivity (i.e., peak/residual ratio) and displacement required to reach peak stress have been determined and the variations in those interface mechanical properties as a function of loading condition and counterface soil type have been investigated. It was shown that the peak as well as residual shear stresses increased with an increase in normal stress for all the interface systems tested. Further, the granular soil (sand) interfaces demonstrated relatively larger frictional strengths (both peak and residual) as compared to both the cohesive soil (clay) interface and the sand/clay admixture soil interface. Additionally, the higher the angularity of granular soil particles became, the larger the interface shear strengths (peak and residual), when sheared against geofoams, developed in light of experimental results attained as a result of interface shear tests on different material combinations. For comparison, the detected peak strength at average for the construction material sand, the beach sand, and the sand/clay admixture soil interfaces as compared to the bentonite clay interface were improved 59.8%, 43.4%, and 20.3%, respectively. Additionally, the detected residual strength at average for the construction material sand, the beach sand, and the sand/clay admixture soil interfaces as compared to the bentonite clay interface were improved 53.9%, 28.6%, and 15.4%, respectively.

Keywords

• Geofoams
• Interface Shear
• Granular Soils
• Cohesive Soils
• Loading Conditions

References

1. Padade, A. H., & Mandal, J. N. (2012). Behavior of expanded polystyrene (EPS) geofoam under triaxial loading conditions. Electronic Journal of Geotechnical Engineering, 17, 2542-2553.
2. Leo, C. J., Kumruzzaman, M., Wong, H., & Yin, J. H. (2008). Behavior of EPS geofoam in true triaxial compression tests. Geotextiles and Geomembranes, 26(2), 175-180. https://doi.org/10.1016/j.geotexmem.2007.10.005
3. Trandafir, A. C., Bartlett, S. F., & Lingwall, B. N. (2010). Behavior of EPS geofoam in stress-controlled cyclic uniaxial tests. Geotextiles and Geomembranes, 28(6), 514-524. https://doi.org/10.1016/j.geotexmem.2010.01.002
4. Tolga Özer, A., & Akay, O. (2022). Interface shear strength of EPS-concrete elements of various configurations. Journal of Materials in Civil Engineering, 34(6), 04022102. https://doi.org/10.1061/(ASCE)MT.1943-5533.0004251
5. Yilmaz, B., & Türköz, M. (2022). Determination of shear strength parameters of compacted high plasticity clay soils based on different laboratory tests. Turkish Journal of Engineering, 6(4), 313-319. https://doi.org/10.31127/tuje.1004043
6. Ertuğrul, Ö. L., & Canoğulları, F. D. (2021). An investigation on the geomechanical properties of fiber reinforced cohesive soils. Turkish Journal of Engineering, 5(1), 15-19. https://doi.org/10.31127/tuje.651222
7. Öztürk, O., & Türköz, M. (2022). Effect of silica fume on the undrained strength parameters of dispersive. Turkish Journal of Engineering, 6(4), 293-299. https://doi.org/10.31127/tuje.1001413
8. Horvath, J. S. (1995). Geofoam Geosynthetic, published by Horvath Engineering. PC, Scarsdale, New York, USA.

9. Horvath, J. S. (1996). The compressible inclusion function of EPS geofoam: an overview. In Proceedings of international symposium on eps (expanded poly-styrol) construction method (EPS Tokyo'96), 72-81.
10. Horvath, J. S. (1997). The compressible inclusion function of EPS geofoam. Geotextiles and Geomembranes, 15(1-3), 77-120. https://doi.org/10.1016/S0266-1144(97)00008-3
11. Horvath, J. S. (1992). New developments in geosynthetics; ‘lite’products come of age. Standardization News, 20(9), 50-53.
12. Bathurst, R. J. (1997). Review of seismic design, analysis and performance of geosynthetic reinforced walls, slopes and embankments, Keynote Lecture. In Proceedings of the International Symposium on Earth Reinforcement (Vol. 2, pp. 887-918). Balkema.
13. Pelekis, P. C., Xenaki, V. C., & Athanasopoulos, G. A. (2000, October). Use of EPS geofoam for seismic isolation of earth retaining structures: results of an FEM study. In Proceedings of the 2nd European geosynthetics conference, Bologna, Italy (pp. 15-18).
14. Zarnani, S., & Bathurst, R. J. (2007). Experimental investigation of EPS geofoam seismic buffers using shaking table tests. Geosynthetics International, 14(3), 165-177.
15. ASTM D854 (2016). Standard Test Methods for Specific Gravity of Soil Solids by Water Pycnometer. ASTM, West Conshohocken, PA.
16. ASTM D4253 (2019). Standard Test Methods for Maximum Index Density and Unit Weight of Soils Using a Vibratory Table. ASTM, West Conshohocken, PA.
17. ASTM D4254 (2016). Standard Test Methods for Minimum Index Density and Unit Weight of Soils and Calculation of Relative Density. ASTM, West Conshohocken, PA.
18. Johnson, K. L. (1982). One hundred years of Hertz contact. Proceedings of the Institution of Mechanical Engineers, 196(1), 363-378. https://doi.org/10.1243/PIME_PROC_1982_196_039_02
19. Johnson, K. L. (1985). Contact Mechanics, Cambridge University Press, Cambridge, UK.
20. Dove, J. E., & Frost, J. D. (1999). Peak friction behavior of smooth geomembrane-particle interfaces. Journal of Geotechnical and Geoenvironmental Engineering, 125(7), 544-555.
21. Frost, J. D., & Han, J. (1999). Behavior of interfaces between fiber-reinforced polymers and sands. Journal of geotechnical and geoenvironmental engineering, 125(8), 633-640. https://doi.org/10.1061/(ASCE)1090-0241(1999)125:8(633)
22. Frost, J. D., DeJong, J. T., & Recalde, M. (2002). Shear failure behavior of granular–continuum interfaces. Engineering Fracture Mechanics, 69(17), 2029-2048. https://doi.org/10.1016/S0013-7944(02)00075-9
23. O'rourke, T. D., Druschel, S. J., & Netravali, A. N. (1990). Shear strength characteristics of sand-polymer interfaces. Journal of Geotechnical Engineering, 116(3), 451-469. https://doi.org/10.1061/(ASCE)0733-9410(1990)116:3(451)
24. Birhan, A., & Negussey, D. (2014). Effects of confinement on the stress-strain behavior of EPS geofoam. In Ground Improvement and Geosynthetics (pp. 536-546). https://doi.org/10.1061/9780784413401.05
25. Khan, M. I., & Meguid, M. A. (2018). Experimental investigation of the shear behavior of EPS geofoam. International Journal of Geosynthetics and Ground Engineering, 4, 1-12. https://doi.org/10.1007/s40891-018-0129-7
26. Özer, A. T., & Akay, O. (2021). Shear strength characteristics of interlocked EPS-block geofoam-sand interface. Geosynthetics International, 28(5), 521-540. https://doi.org/10.1680/jgein.21.00009
27. Meguid, M. A., & Khan, M. I. (2019). On the role of geofoam density on the interface shear behavior of composite geosystems. International Journal of Geo-Engineering, 10(6), 1-18. https://doi.org/10.1186/s40703-019-0103-9