Stability and failure pattern analysis of bimslope with Mohr-Coulomb matrix soil: From a perspective of micropolar continuum theory

Abstract

For the stability and failure pattern analysis of bimslopes, a novel second-order cone programming optimized micropolar continuum finite element method (mpcFEM-SOCP) incorporating the micropolar Mohr-Coulomb (MC) model is developed. Based on two bimslopes, the effectiveness and superiority of the present method is examined. Numerical analyses disclose that the presence of rock blocks “intruding” the potential slip surface may increase the ultimate bearing capacity of the rigid footing and contribute to the stability of bimslopes. Compared to the second-order cone programming optimized classical continuum finite element method (FEM-SOCP), it is interesting to note that mpcFEM-SOCP may reveal different failure mechanisms evidently from those predicted by FEM-SOCP in some cases. For the bimslope with square-cluster rock blocks, it is observed by FEM-SOCP and mpcFEM-SOCP that the presence of scattered rock blocks complicates the failure patterns of bimslopes. Compared to the generalized limit equilibrium method in the Pybimstab package assuming a single slip surface, FEM-SOCP and mpcFEM-SOCP may produce finger-pattern slip surfaces, and particularly the width of slip surfaces in matrix soil may be adequately modeled by the internal characteristic length /_c bridging the particle characteristics of matrix soil and the macroscopic strain localization behavior.

Keywords

bimslope / block-in-matrix structure / micropolar continuum / randomly distributed rocks / tortuous slip surface / volumetric block proportion

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