PROCEDURES FOR ELASTOPLASTIC LIQUEFACTION MODELING OF SANDS

When subjected to undrained cyclic loading, cohesionless soils are known to build up pore-water pressure to the extent that the soil loses the effective confining pressure completely, leading to what is known its liquefaction. Presented in this paper is an elastoplastic model that is capable of describing the stress-strain behavior of sands during such an event. The model is developed by modifying an earlier model, which was shown to be capable of modeling the behavior of sands during monotonic loading. Two procedures, one employing an associated flow rule and another employing a nonassociated flow rule, are proposed for modeling the pore pressure and strain responses during stress reversal, and their potential for modeling liquefaction behavior is explored. The model's capability is examined by comparing the theoretical predictions with experimental triaxial responses.