Generalized shear strain-based model for development of excess pore water pressure in saturated sand under anisotropic consolidation

The development pattern of the excess pore water pressure in saturated sand under anisotropic consolidation conditions is crucial for understanding the liquefaction behavior of sand. In this study, a series of torsional shear tests are conducted using the hollow-cylinder torsional apparatus to examine the influences of the initial consolidation conditions (initial mean effective stress p'₀ and consolidation stress ratio K) and cyclic loading conditions (cyclic stress ratio, CSR) on the development patterns of the generalized shear strain (γ_g) and excess pore water pressure ratio (r_u) in saturated sand. The experimental results indicate that the sands under anisotropic consolidation exhibit three failure modes: cyclic mobility, cyclic liquefaction and residual cumulative deformation. The normalized r_u can be correlated with γ_g for all the three failure modes. A prediction model for the excess pore pressure is proposed considering the anisotropic consolidation conditions for saturated sand. The model can reasonably predict the development of pore water pressure under different consolidation stress states.