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

Understanding the development pattern of excess pore water pressure in saturated sands under anisotropic consolidation conditions is essential to investigating the liquefaction behavior in sands. In this study, a series of torsional shear tests are carried out using hollow-cylinder torsional apparatus to examine the influence of initial consolidation conditions (initial mean effective stress, p'0, consolidation stress ratio, K) and cyclic loading conditions (cyclic stress ratio, CSR) on the evolution patterns of generalized shear strain (γg) and excess pore water pressure ratio (ru) in saturated sands. The experimental results show that sandy soils under anisotropic consolidation state can exhibit three modes of failure: cyclic mobility, cyclic liquefaction, and residual cumulative deformation. For all three failure modes, the normalized ru is significantly correlated with γg. Based on the generalized shear strain characteristics, a pore pressure predictive model is developed taking account of the anisotropic consolidation effects for saturated sand.