Energy-Based Assessment of Liquefaction Behavior of a Non-Plastic Silt Based on Cyclic Triaxial Tests

Abstract

Earthquakes cause cyclic shear deformations in soil and build-up of excessive pore water pressure as a result of undrained loading, accompanied with rearrangement of soil particles and degradation in stiffness of the soil due to decrease in effective stresses. During loading, the onset of soil liquefaction is defined as a stress state in which the excess pore water pressure is equalized to the total stress. From this point of view, assessment of the pore water pressure development pattern under cyclic loading has been one of the most salient research topics in geotechnical and earthquake engineering. In this study, results of a series of cyclic triaxial tests on non-plastic silt specimens consolidated under 100 kPa effective isotropic consolidation pressure were used to question the modelling ability of pore pressure development models previously proposed for sands. Tests were performed on specimens of 6 different initial relative densities (Dr) ranging between 30-80% and 10 different cyclic stress ratios (CSR). The key parameters of pore water pressure development and shear deformation in the energy-based model used are relative density, cyclic stress ratio and number of cycles. The results revealed that, these energy-based models have a strong potential in evaluation of pore water pressure development pattern of non-plastic silts. Test results also show that the increase in relative density and decrease in CSR causes a ladderlike behavior among pore water pressure and cyclic shear strain, which is relevantly rendered by energy-based models.

Keywords

• Pore water pressure
• silt
• cyclic triaxial tests
• energy-based models

References

1. Kramer, S. L., Geotechnical earthquake engineering, Prentice-Hall Civil Engineering and Engineering Mechanics Series, Upper Saddle River, NJ: Prentice Hall. 1996.
2. Towhata, I., Geotechnical earthquake engineering. Berlin Heidelberg: Springer – Verlag, 2008.
3. Amini, P. F., and Noorzad, R., Energy based evaluation of liquefaction of fiber-reinforced sand using cyclic triaxial testing. Soil Dynamics and Earthquake Engineering, 104, 2018.
4. Scott, R. F., Principles of soil mechanics, Addison-Wesley, Reading, Mass. 1963.
5. Lambe, T. W., and Whitman, R. V., Soil mechanics, Wiley, New York. 1969.
6. Dobry, R., Ladd, R. S., Yokel, F. Y., Chung, R. M., and Powell, D., Prediction of pore-water pressure buildup and liquefaction of sands during earthquakes by the cyclic strain method. National Bureau of Standards Building Science Series 138, National Bureau of Standards, U.S. Dept. of Commerce, Washington, D.C. 1982.
7. Green, R. A., Mitchell, J. K., and Polito, C. P., An energy-based excess pore-water pressure generation model for cohesionless soils. Proc., John Booker Memorial Symp.- Developments in Theoretical Geomechanics, D. W. Smith and J. P. Carter, eds., Balkema, Rotterdam, Netherlands, 383–390, 2000.
8. Seed, H.B., Martin, P.P., and Lysmer, J. (1975). The generation and dissipation of pore water pressures during soil liquefaction. Rep. No. EERC 75-26, Univ. of California, Berkeley.

9. Booker, J.R., Rahman, M.S., and Seed, H.B. (1976). GADFLEA—A computer program for the analysis of pore pressure generation and dissipation during cyclic or earthquake loading. Rep. No. EERC 76-24, Earthquake Engineering Research Center, Univ. of California at Berkeley, Berkeley, California.
10. Dobry, R., Ladd, R., Yokel, F., Chung, R., and Powell, D. (1982). Prediction of pore water pressure buildup and liquefaction of sands during earthquakes by the cyclic strain method. NBS Building Science Series 138, National Bureau of Standards, U.S. Dept. of Commerce.
11. Cetin K.O, and Bilge, H.T. (2012). Cyclic Large Strain and Induced Pore Pressure Models for Saturated Clean Sands. Journal of Geotechnical and Geoenvironmental Engineering, 138 (3).
12. Jafarian Y, Towhata I., Baziar M.H., Noorzad A. and Bahmanpour A., (2012). Strain energy based evaluation of liquefaction and residual pore water pressure in sands using cyclic torsional shear experiments. Soil Dynamics and Earthquake Engineering. 35, 13–28.
13. Elgamal, A., Yang, Z., Parra, E. and Ragheb, A. (2003). Modeling of cyclic mobility in saturated cohesionless soils. Int. J. Plast., 19(6), pp. 883–905.
14. Polito, C.P., Green, R.A., and Lee, J. (2008). Pore pressure generation models for sands and silty soils subjected to cyclic loading. J. Geotech. Geoenviron. Eng., 134(10), 1490–1500.
15. Baziar M.H., Shahnazari H., and Sharafi H., (2011). A laboratory study on the pore pressure generation model for Firouzkooh silty sands using hollow torsional test International Journal of Civil Engineering, 9 (2).
16. Lee, K., and Albaisa, A. (1974). Earthquake induced settlements in saturated sands. J. Geotech. Eng. Div., 100(4), 387–405.
17. De Alba, P., Chan, C.K., and Seed, H.B. (1975). Determination of soil liquefaction characteristics by large scale laboratory tests. EERC Rep. No. 75-14, Univ. of California, Berkeley, CA.
18. Seed, H.B. and Lundgren R. “Investigation or the effect or transient loading on the strength and deformation characteristics of saturated sands”,· Proc ASTM, vol. 54, pp 1288-1306.
19. Seed, H.B. and Fead, J.W.N. (1959) “Apparatus for Repeated Load Tests on Soils” Special Technical Publication No 204 ASTM Philadelphia.
20. Seed, H.B. (1960). Soil Strength During Earthquakes, Proceedings of World Conference of Earthquake Engineering, vol I, pp 183-194.
21. Nemat-Nasser, S., and Shokooh, A., A unified approach to densification and liquefaction of cohesionless sand in cyclic shearing. Can. Geotech. J., 16(4), 1979.
22. Davis, R. O., and Berrill, J. B., Energy dissipation and seismic liquefaction in sands. Earthquake Eng. Struct. Dyn., 10(1), 1982.
23. Davis, R. O., and Berrill, J. B., Pore pressure and dissipated energy in earthquakes—Field verification. J. Geotech. Geoenviron. Eng., 127(3), 2001.
24. Yamazaki, F., Towhata, I., and Ishihara, K., Numerical model for liquefaction problem under multi-directional shearing on horizontal plane. Proc., 5th Int. Conf. on Numerical Methods in Geomechanics, Vol. 1, Taylor & Francis Group, London, 1985.
25. Law, K. T., Cao, Y. L., and He, G. N., An energy approach for assessing seismic liquefaction potential. Can. Geotech. J., 27(3), 1990.
26. Hsu, H. L., Study on the relationship between shear work and pore-water pressure for saturated sand in undrained test. First Int. Conf. on Earthquake Geotechnical Engineering, K. Ishihara, ed., Vol. 1, Balkema, Rotterdam, Netherlands, 1995.
27. Wang, G. J., Takemura, J., and Kuwano, J., Evaluation of excess pore-water pressures of intermediate soils due to cyclic loading by energy method. Computer methods and advances in geomechanics, J. X. Yuan, ed., Balkema, Rotterdam, Netherlands, 1997.
28. Green, R. A., Energy-based evaluation and remediation of liquefiable soils. Ph.D. dissertation, Civil Engineering, Virginia Polytechnic Institute and State Univ., Blacksburg, VA, 2001.
29. Cetin, K. O., and Bilge, H. T., Cyclic large strain and induced pore pressure models for saturated clean sands. Journal of Geotechnical Geoenvironmental Engineering. 2012.
30. Polito, C., Green, R. A., Dillon, E., Sohn, C., Effect of load shape on relationship between dissipated energy and residual excess pore pressure generation in cyclic triaxial tests. Can Geotech J. 50(11):1118–28, 2013.
31. Azeiteiro, R.J.N. Coelho, P. A. L. F., Taborda, D. M. G., Grazina, J. C. D., Energy based evaluation of liquefaction potential under non-uniform cyclic loading. Soil Dynam Earthq Eng. 92:650–65, 2017.
32. Karakan, E., Tanrınıan, N., and Sezer A., Cyclic undrained behavior and post liquefaction settlement of a nonplastic silt, Soil Dynamics and Earthquake Engineering, 120, 2019a.
33. Karakan, E., Sezer A., and Tanrınıan N., Evaluation of effect of limited pore water pressure development on cyclic behavior of a nonplastic silt, Soils and Foundations, 59(5), 2019b.
34. Pan, K., Yang, Z. X., Evaluation of the liquefaction potential of sand under random loading conditions: equivalent approach versus energy-based method. Journal of earthquake engineering. 24 (1) :59–83.2020.
35. Karakan, E., Validation of pore water pressure model calibration parameters for non-plastic silt. Fresenius environmental bulletin, 29(12), 2020.
36. Baziar, M.H., Sharafi, H., Assessment of silty sand liquefaction potential using hollow torsional tests—an energy approach. Soil Dynam Earthq Eng. 31(7), 2011.
37. Xu, C., Feng, C., Du, X., Zhang, X., Study on liquefaction mechanism of saturated sand considering stress redistribution. Engineering Geology. 264, 2020.
38. Zhang, W., Goh, A., Zhang, Y. M., Chen, Y. M., Xiao, Y., Assessment of soil liquefaction based on capacity energy concept and multivariate adaptive regression splines. Eng Geol. 188:29–37, 2015.
39. Yang, Z. X., Pan, K., Energy-based approach to quantify cyclic resistance and pore pressure generation in anisotropically consolidated sand. J Mater Civ Eng. 30 (9), 2018.
40. Kokusho T., Liquefaction potential evaluations: energy-based method versus stress based method. Can Geotech J 2013;50(10) 2013.
41. ASTM, Standard Test Methods for Maximum Index Density and Unit Weight of Soils Using a Vibratory Table: D4253-16e1, American Society for Testing and Materials, 14p. 2016.
42. ASTM, Standard Test Methods for Minimum Index Density and Unit Weight of Soils and Calculation of Relative Density: D4254-16, American Society for Testing and Materials, 9p. 2016.
43. JGS 0520-2000, Preparation of Soil Specimens for Triaxial Tests.
44. JGS 0541-2000, Method for Cyclic Undrained Triaxial Test on Soils.
45. Tanrınıan, N., Post-Liquefaction Settlement Behavior of Non-Plastic Silts, Master Thesis, Ege University, İzmir. 2018.