Support design on high slope of Santan quarry for Jinping I Hydropower Station

The maximum height of rock slope of Santan quarry for Jinping I Hydropower Station is 335m and the average slope ratio is 1:0.5.In order to maintain the slope stable in excavation process and after excavation,according to rock composition and geological characteristics,3 slope profiles are selected and 2D finite element analysis is conducted for three excavation schemes.According to the analysis results,together with actual geological conditions,supporting measures are adopted,including building intercepting ditches on slope surface,applying concrete spray and setting drainage holes on the slope surface;reinforcing shallow layer with anchor bolt in different lengths;reinforcing deep layers with anchor cable and anchor bolts etc.Together with construction monitoring data,support measures are continuously adjusted and optimized to comply with the principle of dynamic design.The results show that the design can ensure the slope safety during the construction period and meet the economic and reliable requirements.