SIMULATION OF TOPPLING FAILURE OF ROCKSLOPE BY NUMERICAL MANIFOLD METHOD

摘要

As one type of rock slope failures, topping failure can be accurately simulated only whenseveral aspects are correctly calculated such as deformation and stress, contacts betweenblocks, contact stress, movement of blocks, open/close of contacts between blocks, devel-opment of failure plane, and crack generation and propagation. Current numerical meth-ods encounter many difficulties in simulating toppling failure, especially for rock slopewith lots of rock-bridges. Numerical manifold method (NMM) can deal with these highlydiscontinuous problems and be used to model the toppling failure of rock slopes. Thispaper first introduces the fundamental principles, modeling of contacts, calculation ofcontact force and stress, and modeling of failure in NMM. Then, several case studies areconducted to testify the accuracy and convergence of method; comparisons with method,based on limit equilibrium principle, which was proposed by Goodman and Bray (G–Bmethod) and centrifuge test are conducted. Finally, the topping failure of left bank of onehigh dam is simulated. Results show that the NMM can be used to correctly calculatethe toppling safety factor, simulate the failure process of slope toppling, and accuratelymodel the whole failure process of rock slopes with many rock-bridges.