Rockfall Monitoring Based on Surface Models

Abstract

This research addresses surface analysis based on the Terrestrial Laser Scanning data exampled on rockslope site along M-22 highroad near Ljig in Serbia. The slope is about 100 m wide and over 20 m high. The scanning was performed in three epochs 2011, 2013 and 2014, but only the latter two were involved in the analysis due to insufficient quality of the pilot epoch. Gap between the latter two epochs coincided whit local rockfall events detected in the middle section of the slope. Scanning was performed by Leica ScanStation P20 instrument. Two consecutive point clouds were produced and gridded to 3 cm resolution. Comparative assessment of both point clouds and related surface models revealed the volumes and spatial extents of the anticipated rockfalls. Data were analyzed in two software packages: CloudCompare and GeomagicStudio, that have different modeling approaches based on direct point cloud analysis and mashed surface comparison, respectively. We compared advantages and disadvantages of each approach. Finally, we addressed how LiDAR technology can contribute qualitatively and quantitatively for research and monitoring of rockslopes.