The Research On Xiao Wan High Arch Dam's Abutment Stability And Complex Geological Flaw's Generalized Simulation

As a safe and economic dam type, arch dam has been widely adopted in worldwide countries. With China's putting hydroenergy resource exploitation as a important mission in developing western regions, a lot of high arch dams will be built under complex geological flaw's conditions in the future, especially in southwest China because of special topographical and geological conditions in these areas. Such as, Jinping â… high arch dam, Xiaowan arch dam, Xiluodu arch dam, etc., the geological flaw is the key to these arch dam's abutment stability. In this paper, a lot of recent cases about high arch dam abutment stability have been collected. And methods are summaried, which have been widely adopted now, that is, rigid body limit equilibrium method, finite element method(FEM), and geomechanical model method(GMM). With the development of experiment technology and calculation tool, experiment and calculation have been deeply combined to comparise and analyse abutment stability complementally. According to today's level of experiment and calculation, it's necessary to generalize these geological flaw to simulate no matter which method is adopted. In Xiaowan arch dam site, there are excellent topographical, but complex geological conditions to built an arch dam. In its abutment, many geological flaws have been found, such as, III structure planes(Fi), IV structure planes(fi), joint system near dam abutments, altered zone(Ei), soft rock zone(IIIb2) near abutments, and so on. When FEM and GMM are applied to analyse abutment, a certain generalization is necessary. That whether the generalization is appropriate or not, how much the generalization's influence are to displacement distributing feature, damage feature and mechanism, and degree of safety, should be studied. In this paper, the overloading method is utilized to research initial case and generalized case of Xiaowan arch dam abutment of El.1210. FEM and GMM are adopted to research abutment stability and complex geological flaw'S generalized simulation. Results are comparised and analysed between initial case and generalized case about distributing features of dam displacement, strain, abutment displacement, about damage feature and mechanism. These two cases'safety degree are achieved, initial case's 2.2, generalized case's 1.5. At last, weakness of abutment is put through. And the rational evaluation and treatment measures are made to this generalization.