Characteristic Analysis On Permanent Earthquake-induced Deformation Of 200 Metres High Earth Rock-fill Dams

As the target date about China's commitment to energy reduction approaches, it has an increasing pressure on constructions of non-fossil energy sources. For this reason, China intends to accelerate the pace of developing hydropower construction in Southwest China. It can be expected that a number of large and medium hydropower projects are under construction or about to start. Southwest China is rich in hydropower resources, but it is also earthquake-prone areas. More attentions are paid to the seismic safety of the dams, especially after the earthquake in wenchuan on May 12th, our country has issued a series of documents and requirements on strengthening hydropower projects to defense and resistant earthquake.In hydropower construction, earth-rock dams is widedly used for a lot of advantages, such as short construction period,less investment,wide range of applications,and so on Embankment dam is formed by a collection of loose particles. Under strong earthquakes, rock-fill structures may collapse, subsidence, etc, which affect the safety of dams, therefore, seismic evaluation of embankment dams is an important part of dam design. In recent years, the performance-based seismic design method has been attached to great importance, and it has achieved great development in civil engineering. With regard to earth-rock dams, it is the premise that to predict the seismic permanent deformation accurately, using performance-based seismic design method. The seismic permanent deformation can not only provide a basis for reserving ultra-high, but also can be used as a foundation to evaluate seismic safety of dams.In this paper, first of all, aiming at 200 meters high rockfill dams, the author took a three dimensional static and dynamic finite element analysis, using the Duncan E-B model as static model and the equivalent linear viscoelastic model as dynamic model, studied the dynamic characteristics and seismic response of dams, and then, with the relationship between dynamic stress and residual strain obtained by the tests done on the dam materials by IWHR, studied the distributions seismic permanent deformation, using the equivalent nodal force method.Second, based on discussing the seismic response of dams under different initial shear modulus or different selections of nonlinear variations of shearmodulus and different damping ratio with shear strain, the author analyzed the influence on characteristic values and distributions of seismic permanent deformation under the changes of dynamic parameters, and obtains the variation of permanent deformation in the end.Finally, the author took a research on permanent deformation affected by seismic input. In the research, the author selected different response spectrum parameters, fitted artificial wave according to the design response spectrum curve provided by the specifications'seismic design of hydraulic structures (DL 5073-2000)', analyzed seismic response and seismic permanent deformation of the dams under different seismic inputs, and obtains seismic permanent deformation discipline of different response spectrum parameter at last.