A DEM-BASED METHOD FOR IDENTIFYING ROCKFALL HAZARDS ALONG RAILWAY LINES

Abstract

 An efficient way to identify rockfall hazard areas on wide-area slopes along railway lines is to use the results of quantitative assessment of slope features based on numerical elevation models. In this study, the slope gradient and ground point ratio were calculated based on the spatial numerical information after automatic ground point filtering, and a schematic extraction method of the fall type rockfall source was proposed using these results. A new point cloud filtering process was then performed to reproduce the fine ground surface including boulders on the extracted slopes, and an evaluation method was proposed to objectively compare the slope profile based on the difference in specific height between the point clouds after offset filtering. Furthermore, a method for identifying rockfall hazard areas based on a numerical elevation model, which takes into account the empirical methods practiced by railway field engineers, is presented by means of a case study.