Liquefaction Potential of Dams and Foundations. Report 5. Development of a Constitutive Relation for Simulating the Response of Saturated Cohesionless Soil.

摘要

This report documents the development of a three-dimensional elastic-plastic isotropic constitutive model for earth materials and demonstrates its ability to simulate a wide variety of observed stress-strain-pore pressure responses of fully saturated cohesionless soils. The model reproduces the hysteretic behavior exhibited by these materials when tested under hydrostatic and deviatoric states of stress, and accounts for shear-induced volume changes, strain-softening response, and progressive increases in pore pressure due to subfailure cyclic loadings. The undrained condition for fully saturated materials is simulated by the assumption that for each loading increment, the corresponding increment of volumetric strain is zero. The behavior of the model under simulated undrained triaxial test conditions is examined in detail and correlated with experimental data for saturated Reid-Bedford Model sand and Banding sand. It is recommended that the present constitutive model be incorporated into a suitable computer code for use in conducting numerical effective-stress analyses aimed at assessing the liquefaction potential of earth dams or other earth structures subjected to earthquake-type loadings. (Author)