Constitutive model for fluid of post-liquefied sand

The static load tests on post-liquefied saturated Nanjing fine sand are carried out using the hollow cylinder apparatus. The effect of the initial effective confining pressure and loading rate on the fluid characteristics of post-liquefied saturated Nanjing fine sand is taken into account. The results show that the development process of the shear stress and pore water pressure ratio have obvious two-stage characteristics in static loading process, and they have a a good linear relationship. The effective confining pressure and the static loading rate have obvious influence on the relationship between them. On this basis, a constitutive model for fluid with rate and pore water pressure-dependent static loading process is proposed. In this model the friction resistance between soil particles and the viscous resistance between soil and water are respectively expressed as the thixotropic shear-thinning fluid and non-time-variant shear-thinning fluid. Finally, experiments and comparisons between the predicted curves and other researchers′test results are carried out, indicating that the proposed constitutive model has good applicability.