STABILITY ANALYSIS OF DAGANGSHAN DAM ABUTMENT SLOPE UNDER EARTHQUAKE BASED ON PSEUDO-STATIC METHOD
LIU Jie1，LI Jianlin1，2，ZHANG Yudeng3，QU Jianjun2，LI Jianwu2，LI Yingxia2
(1. College of Civil and Hydropower Engineering，China Three Gorges University，Yichang，Hubei 443002，China； 2. Key Laboratory of Geological Hazards on Three Gorges Reservoir Area，Ministry of Education，China Three Gorges University，Yichang，Hubei 443002，China；3. HydroChina Guiyang Engineering Corporation，Guiyang，Guizhou 550002，China)
Abstract：The general engineering situation of an abutment slope located in the complex area of Dagangshan Hydropower Station with the maximum design and check seismic intensity at present in China is introduced. According to relative regulations，the pseudo-static method is selected to analyze the stability of Dagangshan dam abutment slope under earthquake；and the method has been improved correspondingly. Based on reasonable rock mass parameters，anchoring parameters and seismic parameters of slope，the stress，strain，plastic zone of the slope under different earthquake accelerations and the cable¢s stress are studied. Then the variation laws of displacement of critical points changing with slope height under different geological conditions and seismic intensities are pointed out；and the main affected area(sensitive area) of different sections under earthquake，the evolutionary laws of plastic zone in the process of earthquake and the corresponding slip modes are obtained，which could offer references for supports. It is considered that，under the earthquake acceleration with 5% exceeding probability in the next 50 years，large plastic area appears in the rock grade V，accumulation body and the areas with rock dikes γL5，γL6，XL316–1，XL9–15 and β6. The plastic areas become larger and show a tendency of transfixion. It is shown that layers in the rock grade V and rock dikes XL316–1，XL9–15 are important for stability of rock slope. It is also suggested that parameters of rock grade V needs to be adjusted so as to further ascertain the distribution and connectivity rate of rock dikes XL316–1，XL9–15.
