Abstract：The powerhouse of the Shiquan hydropower station is located near the river bank. The turbine pit excavation depth is about 42 m. During excavation，collapse of surface layers of the rock slope happened twice，and a crescent open space was formed between the powerhouse and the rock slope. According to geological structure characteristics of the collapse exposure，the collapse mechanism of the high slope was analyzed. On this basis，a reinforcement scheme was designed. Required force for the pre-stressed cable bolt was optimized by the limit equilibrium computation. Interactions between the slope and concrete frame were analyzed by a 2D contact-nonlinear FEM. Based on the numerical simulation results，a comprehensive treatment and reinforcement scheme of building concrete frame in the crescent open space was worked out. The idea is to utilize the elastic resistance generated from the moderate distortion of the concrete frame to increase the stability of the slope foot. The practical cases show that this scheme not only increases the safety degree of the slope，but also provides favorable economical benefit.
