NUMERICAL SIMULATION OF DEFORMATION PROCESS AND FAILURE MECHANISM OF RESERVOIR BANK SLOPE WITH LARGE-SCALE ANTI-DIP ROCK MASS 

The primary deformation and failure mechanism of reservoir bank slopes with anti-dip rock mass are dominated by the geological structure, stratum lithology and inducing loading factors. The Longpan slope is located at the right embankment of Dale dam on Jinsha River. It consists of anti-dip alternate sandstone and slate strata. The thick riverbed sediments form a soft basement of the slope. This paper takes the Longpan slope as a case study and uses the discrete element method to simulate the deformation evolution process of the slope rock mass. Based on the viewpoint of time-dependent deformation, the strength reduction method is introduced to evaluate the factor of safety of the anti-dip rock slope. The numerical modeling result verifies that the geological mechanism is actually a deep-seated gravitational bending deformation. In accordance with the expansion way of the shear yielding zones, the progressive shear failure mechanism of the large-scale anti-dip rock masses with effects of interbedded strata and soft foundation is proposed in the paper. This mechanism is believed to have significance in the slope failure prevention. 