An endochronic approach in modeling liquefaction of sand

摘要

Liquefaction is the transformation of cohesionless saturated soil skeleton from loose to densernstate causing reduction of shearing resistance due to increase in pore water pressure and drop in effective stress.rnUnderstanding the liquefaction behaviour is limited mainly to empirical approaches, although progress hasrnbeen made in constitutive modeling, models which could account for the volumetric changes due to variationsrnin effective stress and that could realistically capture the liquefaction phenomenon were seldom achieved. Inrnthe present study a pseudo coupled endochronic viscoplastic constitutive model is developed to study thernliquefaction behaviour of sands. Endochronic model is based on the observation of the state of stress in thernneighborhood of a point in a plastic material and rapidity of deformation of the neighborhood. The modelrnincorporated in to FLAC3D using user defined constitutive model is validated with static and cyclic triaxial testrndata and is found to predict accurately the liquefaction phenomenon.