SIMULATING THE BEHAVIOR OF SOFT COHESIVE SOILS USING THE GENERALIZED BOUNDING SURFACE MODEL

Abstract

The Generalized Bounding Surface Model (GBSM) for saturated cohesive soils is a fully three­dimensional, time and temperature-dependent model that accounts for both inherent and stress induced anisotropy. To better simulate the behavior of cohesive soils exhibiting softening, the model employs a non­associative flow rule. The GBSM synthesizes many previous bounding surface constitutive models for saturated cohesive soils and improves upon their predictive capabilities. For those cases where the use of the more complex forms of the GBSM is not justified, the model can be adaptively changed to simpler forms, thus reducing the number of associated parameters, giving flexibility to the simulations and reducing the computational cost. Following a brief overview of the GBSM, the model's performance in simulating the response of soft, saturated cohesive soils is assessed under both axisymmetric and true triaxial conditions.