大坝岩基深层滑动面的可靠度分析

RELIABILITY ANALYSIS OF DEEP SLIDING PLANE IN ROCK FOUNDATION UNDER DAM

建立了一种对大坝岩基深层滑动面的可靠度分析的方法。首先运用Mohr-Coulomb破坏准则推导出局部破坏的判别法,从而得到对应某一初始点的滑动面。然后运用了瑞典条分法计算岩基安全系数的公式,使其作为目标函数,使用了人工鱼群算法得到了初始点,从而确定了滑动面。最后,使用最小二乘法,用直线拟合了滑动面。并对主滑动体和尾岩抗力体进行受力分析,得到了功能函数。通过Monte-Carlo法,得到功能函数的期望值和方差,从而得到大坝岩基深层滑动面的可靠度。结合了实例说明了此种方法的有效性。与常规求大坝岩基深层滑动面的可靠度的方法相比,此方法有其优点:中间过程采用有限元分析方法对应力状态进行了分析,得到的可靠度是偏于安全的。

In this paper,an improving method for reliability analysis of deep sliding surface in rock foundation under dam is established.Firstly,Based on Mohr-Coulomb failure criterion,partial destructive discriminance is derived.The only slip plane can be got to some initial point.Then based on sweden slice method,formula of the safety coefficient of the slope's stability can be as objective function,through artificial fish-swarm algorithm,slip plane in rock foundation under dam can be established.Finally,based on least square method,the slip plane is fitted by two straight lines.And the force analysis of main slide mass and tail rock resistance block is used to determine performance function.Based on Monte-Carlo method,the value of expectation and variance of performance function and the reliability of deep sliding surface in rock foundation under dam are obtained.This method is verified by an example,which proved that the method is feasible and available.Compared with other conventional algorithm,this method has some strong points: in this course,a finite element analysis of the stress state is used.The reliability of deep sliding surface in rock foundation under dam is conservative.