EVALUATION OF PLASTICITY-BASED SOIL CONSTITUTIVE MODELS IN SIMULATION OF BRACED EXCAVATION

Abstract

Numerical modelling continues to play a unique and intrinsic role in the process of geotechnical design. Of greatest concern are soil constitutive models that are employed within finite element software to predict soil behaviour. The objective of this paper is to provide a numerical study of the Mohr-Coulomb and Hardening Soil constitutive models in simulation of a braced excavation. The Taipei National Enterprise Centre (TNEC) basement construction process was well documented and the commercial finite element code, Plaxis, was selected for this numerical comparative study. It was found that the Mohr-Coulomb soil model, a first order approximation, produced an underestimation of the diaphragm wall deflection, whilst the Hardening Soil model provided a good prediction of the observed in-situ diaphragm wall deflections