Analysis of Rock Fall Phenomenon in Steep Wall Using Modeling by Rocfall Mass-Lump Method and PFC3D Discrete Element Method - Case Study

Rock fall is a type of slope instability that occurs in most mountainous areas and causes casualties and severe damage to facilities, residential areas, roads, farms and vehicles. Therefore, to prevent financial damage, it is necessary to predict and model the phenomenon of rock fall in steep walls to take preventive measures. In this paper, in order to assess the risk of falling rocks, first using Rocfall software, the path of rock fall of isolated blocks was analyzed individually and separately in the most critical section of the northwestern heights of Shahrood. In order to consider the interactions between particles in the path, shape, size and weight of the parts, the distinct element method PFC3D was used. Analyzing the simulation results with the help of these two softwares, it was concluded that if the rock falls, a large number of parts will stop in the area of ​​roads and residential areas, which will result in traffic jams and financial-human risks. In other words, considering that the maximum horizontal distance traveled by the plots is 393 meters and the horizontal distance between residential areas is 340 meters, so the probability of an accident due to falling rocks is very high. In the following, suggestions such as installation of metal grids, shock absorbers, reduction of kinetic energy in the parts, change in the dimensions of the parts, change of the slope geometry to reduce the risk and damage caused by falling rock in the desired section are presented.