Earthquake Response of Xieka Concrete Face Rockfill Dam by FEM

The Xieka hydropower station is located on the Taka River in Sichuan province China, where the design earthquake intensity is 7 degree. Its concrete face rockfill dam is about 108m high with about 45m to 100m thick overburden layer. According to the actual engineering conditions of Xieka dam, the 3-D non-linear FEM dynamic model of the dam is set up for calculating earthquake response. By simulating the process of the filling of dam and reservoir impounding, the original static stress field of dam body is obtained firstly under the normal water level. Then by the dynamic time-history analysis method, the earthquake response of the dam is calculated and obtained for inputting the design earthquake with peak acceleration of bedrock 109cm/s², including acceleration response, displacement response and stress response etc. The acceleration response along the up-downstream direction is the maximum with 7.6m/s², the one along the dam axis is secondary with 4.8m/s², and the one along vertical direction is the minimum with 2.9m/s² . The maximum displacement responses of dam are 56mm, 31mm and 17mm respectively in aforesaid three directions, and the maximum principle stress responses of rockfill are 871kPa, 678kPa and 598kPa respectively. The maximum stress response of face slab is about 4819kPa in the dam slope direction. It is shown that the earthquake response of the dam is consistence with the general law. The analysis results show that the design of the dam is reasonable in technique.