在考虑土性参数的不确定性和土体应变软化特性的基础上，以可靠度方法建立了边坡渐进破坏的极限状态方程。通过计算边坡局部破坏概率，确定边坡中最危险的土条，并推导出破坏起始于该土条，逐渐向两侧扩展的渐进破坏概率计算公式。该方法能很好地反映边坡局部破坏的产生、扩展及对边坡整体稳定性的影响，找到最贴近实际情况的破坏传播路径，为边坡稳定分析提供了理论依据。通过算例分析可知，滑动面上各个土条的局部破坏概率均不相等，破坏起始于中部第8土条，破坏先向上传递，后向下传递至坡脚，并非从坡脚向坡顶传递的牵引式破坏，或从坡顶向坡脚传递的推移式破坏。

Considering the uncertainty of soil parameters and soil strain softening characteristics, the reliability theory is used to establish the limit state equation of the slope progressive destruction, which is to calculate the slope probabilities for the partial failure and the progressive failure. The mode of failure considered here is that failure initiates within an assumed slip surface in the ‘weakest’ segment and progresses outwards from that segment along the slip surface. The reliability analysis method of the slope progressive failure can well reflect the partial slope body failure including its emergence, extension and its influence on the entire slope reliability. Then we can determine the most realistic failure propagation path and provide a theoretical basis of slope stability analysis. The example shows that the partial failure probability of each segment along the slip surface is not equal. Initiating from the eighth segment, the failure passes up at first and then down to the toe, which is different from the traction type failure, initiating from the toe and passing to the top, and the passage type failure, initiating from the top and passing to the toe.