Movement of collapsed stones on the slopes is affected by many factors

therefore

its analysis and prediction is very difficult. Determining the damage range of collapsed stones is very important to the prevention of collapse disaster. Based on site measurement and statistical analysis of 399 sections of collapse induced by the Wenchuan earthquake

the movement characteristics and hazard range parameters of collapsed stones on slopes are studied. The main conclusions are drawn as follows. (1) Movement of collapsed stones on slopes can be divided into three stages

that is

initiating stage

movement stage and depositing stage. The limit between free falling and sliding-rolling model in initiating stage is 56º; the maximum slope angle of deposition zone is 39.6º; and the slope angle of deceleration zone is below 26º. (2) Ratio between moving distance and the height of slope

increases with the increase of earthquake intensity and rock strength; and a statistical formula is given. (3) We get good linear relationship between the maximum moving distance and height slope

as well as between slope angle in the steep sections and spread angle. According to the proportion of deposition area in the whole slope

the slope shape is divided into two kinds; and the statistical diagram of the relationship between the maximum moving distance and spread angle is given which may be useful for determining the damage scope of collapsed stones.