Study On Stability Analysis And Permanent Deformation Of High Rock-fill Dams Under Strong Earthquakes

West china is abundant in hydropower resources, so large-scale major infrastructures such as high dams have been or to be constructed or under planning or under designing. These constructions are propitious to alleviate the disaster caused by drought and flood in the lower region, and also make for improving the structure of energy and relaxing the shortage of electricity power. Because most of western areas located in high earthquake intensity regions, so the evaluation of earthquake-resistant behavior and seismic safety of these high dams is very important. Once the dam destroyed, many people will lose their lives. After the wenchuan earthquake, people pay more attention to the seismic safety evaluation of high rockfill dams.In this article the slip surface was described by several variables. The factor of safety was calculated by using Morgenstern-Price method. The seismic stability analysis was based on the non-circular slip surface and the harmony search algorithm.Based on the non-circular slip surface, the potential sliding body was brougt forward. The time-history average yielding acceleration and the time-history average sliding acceleration was presented on the basis of time-history vertical acceleration. The accumulation of sliding displacement of potential sliding bodies was the actually sliding acceleration's twice integra-tion. Then the degree of dam's safety was judged by the potential sliding bodies'accumu-lation of sliding displacement.Based on real projects and Dynamic Triaxial Test, the safety factor of filter under seismic loads was estimated by Seed. Concerning part dam materials'shear strength depress after the powerful earthquake, the critical surfaces and their accumulation of sliding displacements were presented. It provided scientific basis for the design of the dam. The dam which was reinforced by Geogrid was discussed by equivalent additional stress method. The permanent deformation was calculated by equivalent nodal force method on the basis of static and dynamic element analysis.