Influence of Anisotropy and Nonhomogeneity on Stability Analysis of Slurry-Support Trenches

Abstract

A method for assessing the stability of slurry-supported trenches considering anisotropy and nonhomogeneity using the upper-bound theorem of limit analysis is presented. Only anisotropy and the nonhomogeneity of the cohesion were taken into account in this study. The influence of anisotropy and nonhomogeneity on trench stability was investigated via parametric studies. A series of stability charts was obtained for slurry-supported trenches. It is shown that the results obtained from the upper-bound solutions agree well with those obtained through the variational limit-equilibrium closed-form solutions in isotropic and homogeneous trenches. This article first describes the influences of anisotropy and nonhomogeneity on the required unit weight of slurry, and then the procedures for getting the factor of safety are presented. In addition, the influence of anisotropy and nonhomogeneity on the shape of the trench critical failure surface and on the location of the slip surface of the sliding mass is decribed. The article also gives examples to illustrate the variation in the safety factor with trench depth under different anisotropy and nonhomogeneity conditions.