A huge slope failure occurred in Kuishanhu of Chinshan area after Xangsane typhoon on 1st Nov, 2000. The mainly composition of study area are lava flow and pyrocrastic rock. The study area is divided into two divisions, one is failure zone and the other is accumulated zone. The failure zone includes three parts: major scarp, minor scarp and main body. The length of the failure zone is 150m and the slope grade ranges from 45° to 82°. Three sets of joints are (1) N60°E/ 80°N, (2) N60°W/78°S and (3) N8°W/11°N. The accumulated zone includes two parts: foot and deposition area. The length of the accumulated zone is 250m and the slope grade ranges from 0° to 15°.
