Analyses of braced excavation considering parameter uncertainties using a finite element code

Abstract

This study presents a simplified procedure to quantify the effect of parameter uncertainty with consideration of soil spatial variability in analysis of braced excavations. A well-documented case history is adopted in conjunction with PLAXIS, a proprietary finite element code. The simplified approach based on first-order approximation is easy to use, requires less computational work and provides a practical tool to estimate the variation of the wall and ground responses caused by the uncertainty in input parameters. Moreover, to facilitate the numerical analysis, this study also documents a successful implementation of user-defined soil models, including the hyperbolic and the modified pseudoplasticity soil models, into PLAXIS. The results show that PLAXIS, with these user-defined soil models, can capture the laboratory stress–strain relationships and predict, accurately, the wall and ground responses in a braced excavation.