Modeling of liquefaction-induced shear deformation

摘要

A constitutive model is developed to reproduce salient aspects associated with seismicallyinduced soil liquefaction (medium to dense clean cohesionless soils). Attention is mainly focused on the deviatoric (shear) stress-strain response mechanism. Soil cyclic shear behavior during liquefaction is modeled to display a significant regain in stiffness nad strength with the increase in deformation during each cycle of applied load. This behavior appears to play a major role in dictating the magnitude of shear deformations as observed in laboratory tests and manifested in acceleration records from earthquakes and centrifuge experiments (clean sands and non-plastic silts). Constitutive model parameters are selected to represent medium, medium-dense and dense clean cohesionless soils. Using these parameters, the resulting model response is presented under simple-shear cyclic loading situations. Further modeling accuracy may be achieved based on a more thorough understanding of the underlying physical processes.