Soil Dynamic Constitutive Considering Post-Liquefaction Deformation and Reversible Pore-Water Pressure

Abstract

In the seismic response analysis of liquefiable sites, the existing soil dynamic constitutive model is challenging to simulate saturated sand’s post-liquefaction deformation, and the current pore-water pressure buildup model cannot reflect the decrease in the actual pore-water pressure under unloading stress. We aim at these problems to propose a feasible and straightforward time-domain post-liquefaction deformation constitutive model through experimental analysis and theoretical research, consisting of reversible pore-water pressure. According to the dynamic triaxial test data, the regularities of large deformation stress and strain behavior of the saturated sand after liquefaction are obtained, and the corresponding loading and unloading criteria are summarized. Combined with the effective stress constitutive model proposed by the author, a soil dynamic constitutive that can describe saturated sand’s post-liquefaction deformation path is obtained. According to the test results, the model can simulate the deformation of saturated sand during the whole liquefaction process. The self-developed program Soilresp1D realized the dynamic response analysis of the liquefiable site, and the results were compared with the experimental results. It shows that the model based on the effective stress-modified logarithmic dynamic skeleton and post-liquefaction deformation constitutive can be directly applied to the dynamic response analysis of the liquefiable site.

Study on Dynamic Performance of Standard Sand Based on KTL Dynamic Triaxial Apparatus

“…It is necessary to control the development and change of soil dynamic behavior in the process of liquefaction, and the stress-strain relationship of sand and the change law of pore water pressure are some of the key problems. Fu et al [17] and Feng Dong et al [18] proposed the incremental model of pore water pressure to calculate the pore water pressure under irregular load, but their models were derived from the theoretical formula. Sun and Yuan [19] proposed the pore water pressure increment model of Harbin sand under unequal consolidation by using the triaxial test, which was greatly limited in application.…”