边坡渐进破坏三维可靠性分析

THREE-DEMENSIONAL RELIABILITY ANALYSIS OF SLOPE PROGRESSIVE FAILURE

本文从三维观点出发,对边坡的渐进破坏进行了系统研究。渐进破坏是沿着临界滑面在空间上连续发展的过程,以抗剪力与剪力之差定义安全余量,用破坏转移概率判别破坏区的渐进扩展。将粘聚力、内摩擦角、水压力参数看作是相关的且服从正态分布的随机变量,各条柱的安全余量服从正态分布,破坏区与其周围条柱安全余量的联合分布认为是二维正态的。用Rosenbluth法计算各安全余量的均值和方差。本文最后对某露天煤矿的滑坡实例进行了计算分析,其结果与实际观测及边坡破坏的机理试验有很好的一致性。

From three-dimensional viewpoint, the progressive failure of a slope is systematically analysed based on reliability theory in this papar. The progressive failure is defined as a spatial and continuous extension on a critical slip surface. The safety margin is given by the difference between shear resistance and shear force. The progressive extension of failure is determined according to transition probability of failure. Cohesion, inter-friction angle and pore water pressure are considered as correlative random variables. The safety margin of any column is assumed to follow a normal distribution. The joint distribution of the safety margins of failured aera and the column close to the aera is assumed to be bivariate normal. Mean and variance of any safety margin are calculated by using Rosenblueth's method. Analysis results of the typical landslide of a surface coal mine are conformable to those of pratical observation and slope failure mechanism experiments.