Reliability Analysis Of Gravity Dam Deep Stability Against Sliding

Anti-sliding stability analysis is an important part of the gravity dam design,over the years damming technology unceasing enhancement,the design theory also constantly improve,so now gravity dam in general will not happen along the foundation surface or shallow bedrock failure.When problems under the dam may cause sliding failure of soft rock in dam,it is necessary to check its deep stability against sliding,now main use safety coefficient method and reliability theory to analyze the deep stability against sliding.Finite element strength subtraction calculation of dam foundation stability against sliding overall safety coefficient has been widely used in engineering,the method is the key to determine the dam foundation reaches limit equilibrium state,and reasonably select the material yield criterion.This article is based on the finite element software ANSYS,through engineering example analyzes the breakthrough of the plastic zone,displacement mutation and nonlinear calculation convergence of three kinds of judgment on the basis of the safety factor of dam foundation instability criterion shows that three conclusions are consistent.The five principles of DP series are analyzed,the calculation example shows that there is no greater difference between yield criterion results,compared with the traditional rigid body limit equilibrium method,the results,the plane strain non-affiliated rule matching DP5 Mohr-coulomb criterion of relative error within 5%,relative error of DP1 ~ DP4 is bigger,in 10% ~ 30%.Gravity dam deep sliding is low probability events,using the traditional reliability analysis method—Monte Carlo method to calculate the reliability index,it need a lot of simulation times to get relatively accurate value,and because of the complexity of the functions and highly nonlinear,JC method to solve the reliability index easily in a infinite loop in the iteration process.So this article will introduce a swarm intelligence optimization reliability index calculation,put forward the global human colony algorithm based on crossover operation reliability model method(CGABC)and the contraction factor of the particle swarm algorithm(XPSO)reliability optimization model,the example analysis shows that CGABC method and XPSO method to solve the deep gravity dam stability against sliding always faster convergence and accuracy and reliability of Monte Carlo method.Compared to the CGABC method and the XPSO method convergent process,the XPSO method performs better.