Slope project is often appearing in rock and soil engineering such as water conservancy, mine, highway and railway etc. And deposit slope is a special natural one. For probing into slope failure mechanism and prestressing loss of anchorage cable in deposit body, this paper researches it by numerical simulation. Study result shows: First, three leading influence factors, which are deposit slope lithology and structure, in-situ stress, and groundwater, may induce slope failure; Second, slope failure patterns chiefly includes landslide along the interface between bed rock and deposit, and part circular slippage in shallow deposit body; Last, it appears prestressing positive loss and negative loss of anchorage cable in study area, especially the latter occurs because of the slide interface existing in deposit body, and changing technical parameters of anchorage cable can partly improve prestressing loss.

In order to sum up structure geology and engineering geology of project area in Xiao-wan by the numbers, the author summarizes it on the base of pre-researchers production. The summarizing includes two parts, that is structure geology and engineering geology, and the paper stands out the keystone and core content respectively. The structure geology content consists of zone of fracture, fault, joint, structural stress field and seism. However, engineering geology summarizing includes terrain, lithology, geological action, hydrogeology and alteration of rock body and so on.