Multistep rocky slope stability analysis based on unmanned aerial vehicle photogrammetry

High-steep slope information collection and multistep rocky slope stability analysis play an important role in slope engineering. However, traditional on-site investigations suffer from terrain restrictions and data omissions. This paper presents a block identification method based on UAV (unnamed aerial vehicle) photogrammetry and its computer implementation. An SfM (structure from motion) method is introduced and a 3D reconstruction software-PhotoScan was used to build the DEM (digital elevation model) of the rock mass for real-time monitoring. Then, an RANSAC (random sample consensus) shape detection algorithm was used to search the structural planes in the point cloud model. A computer program GeoSMA-3D (geotechnical structure and model analysis-3D) has been developed to implement engineering applications and a case study was carried out which confirmed the efficiency of the method in dealing with complex surface modeling and multistep rocky slope stability analysis.