Study On The Stability Of High Arch Dam Abutment By Three-dimensional Geomechanical Breakage Model Test

With the development of Hydraulic power enterprise, and the need of west development, the trend of Hydroelectric engineering are high dam, big reservoir capacity and large installed capacity. Especially the height of the concrete arch dam has already been about 300m. Such as the proposed arch dam of XiIuodu(278m),Xiaowan(292m) and the primary Jingping(305m). And where the project will be built, the topography, geologic and hydrologic conditions are usually very complex, so the safety is the key to the high arch dam proposed. The stability of the dam abutment is the guarantee to the project's safety. During the ninth-five-year's tackling key problem plan, that the high arch dam conclude the stability of dam base and abutment was studied emphatically. Now the numerical analysis and model test are two kinds of means to dam abutment's stability analysis. With regard to the model test, the geomechanical model test has made great progress in model material, simulation technique and test means. Especially when the imitative temperature similar material was researched successfully, it made the means of strength reserve become true.This article is based on the topography and geologic character of Xiluodu arch dam base and abutment, and the interlayer and internal disturbed belt, and the distribution of joint and crack, which controll the stability of the project. To study the stability of dam base and abutment, physical model test and numerical analysis are used. First, we carried out an experiment by three-dimensional geomechanical model test. In the test, several imitative temperature similar material were used to simulate the dam base and abutment, further more, overload and strength reserve were jointlyused. Then the influence of the additional temperature field to the test result in the material was analyzed. The analysis is based on America finite element general soft ware named ANSYS. The non-linear structure analysis, temperature analysis and coupling temperature with structure analysis were used together to estimate how much the additional temperature field influenced the test result. The following are the results gotten by the study:Firstly; the test demonstrated the destruction process and destruction condition of the dam base and abutment. The test also revealled the failure mechanism of the dam base, and thus the opinions of reinforcing treatment were suggested.Secondly, the degree of synthesis safety of Xiluodu arch dam abutment is obtained as 6.3Thirdly, the additional temperature field's influence to displacement is about 6%, to stress it is about -6~9%. And the lower temperature degree is, the little influence degree is.Lastly, the structure and the coupling analysis showed the reliability of the result of the geomechanical model test, and the feasibility of the mutative temperature similar material, which was used in the geomechanical model test.