Approximate Simulation of Natural Structured Soft Clays Using a Simplified Bounding Surface Model

Abstract

A simple version of a recently proposed anisotropic elastoplastic bounding surface model was used to simulate the mechanical behavior of natural Shanghai soft clay. The characteristics of stress–strain curves attributable to structural deterioration were approximately simulated by the model using a lower-level parameter s for the elastic nucleus. Successful simulation was achieved because, from the viewpoint of engineering applications, the bounding surface is equivalent to the structure surface, and the elastic nucleus is approximately equivalent to the reference surface. The model was expressed with a total of nine parameters. Simulations were carried out on isotropically and anisotropically consolidated specimens with varying preconsolidation pressures under undrained conditions and on stress-probing tests from the in situ stress states under drained conditions. The simulations were found to be satisfactory compared with the test results. Thus, the possibility of simulating natural clays with low to medium sensitivity using a simplified version of the bounding surface model with a carefully defined elastic nucleus was demonstrated.