考虑变量相关性的尾矿坝坡失稳溃坝概率计算方法

Calculation method on probability of tailings dam failure caused by dam slope instability considering correlation of variables

对国内外尾矿坝溃坝事故进行整理分析,得出坝坡失稳是导致溃坝的一个主要原因,利用突变理论对坝坡失稳进行分析,从突变学角度证明内摩擦角和粘聚力是尾矿坝坡失稳溃坝的主要影响因素。摒弃传统的尾矿坝抗滑稳定性安全系数定值计算方法,选取综合考虑诸因素的不确定性的概率方法来计算尾矿坝坡失稳溃坝概率,确定内摩擦角和粘聚力作为随机参数,建立尾矿坝坡失稳破坏的功能函数,确定模拟次数;采用考虑随机变量相关性的蒙特卡罗进行尾矿坝坡失稳溃坝概率计算。该方法成功克服了matlab传统子集模拟方法只能解决随机变量为正态分布且变量之间相互独立的不足,并以某尾矿坝为例对其因坝坡失稳导致的溃坝概率进行了计算。

The accidents of tailings dam failure at home and abroad were analyzed,and it showed that the dam slope instability was a major reason causing dam failure. The dam slope instability was analyzed by the catastrophe theory,and it proved from the perspective of catastrophe that the internal friction angle and cohesion strength were the main influence factors of dam slope instability and failure. Abandoning the traditional calculation method on anti-slide stability safety coefficient of tailings dam,the probability method comprehensively considering the uncertainty of each factor was selected to calculate the probability of dam failure. The internal friction angle and cohesion strength were taken as random parameters,the function of dam slope instability and failure was established,and the number of simulation was determined. The Monte Carlo considering the correlation between random variables was applied to calculate the probability of dam failure. This method overcomes the shortcomings that the traditional Matlab subset simulation method can only solve the problems that random variables are normal distribution and the variables are independent. Taking a tailings dam as example,the probability of tailings dam failure caused by dam slope instability was calculated.