THREE-DEMENSIONAL RELIABILITY ANALYSIS OF SLOPE PROGRESSIVE FAILURE

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.