关键词: 楔型体, 稳定性, 极限平衡法, 风化作用, 静水压力

Abstract: This paper presents the case history of a rock slope which failed six years after the excavation. The failure mechanism was analyzed throughout the field investigation before and after the sliding, physical and mechanical test of the rock mass and the stability evaluation. It is found that the failure modes of the slope are mainly wedge sliding. The excavation and the rainfall also accelerated the weathering of the slope rock mass. The XRD test showed that, compared with the fresh rock, the clay mineral composition in the weathered rock increased, which resulted in the decrease of the rock mass strength. The shear strength parameters of the weathered joints were determined by the Barton-Bandis criterion, and the stability of the was analyzed by the limit equilibrium method. Considering the dynamic change process of the groundwater, the slope stability was evaluated based on two types of water pressure models. The results showed that the slope stability decreases gradually, with the increase of the water pressure, and eventually led to the failure. According to the failure mechanism, suggestions were proposed for the slope treatment.

Key words: Rock Wedges, Stability, Limit Equilibrium Method, Weathering, Water ressure