Quantitative assessment of rockfall hazard in post-landslide high rock slope through terrestrial laser scanning

Post-landslide high slopes have always been at increased risk for rockfall disasters, posing a considerable threat to the slope toe area and making it very difficult to manage. In this paper, a comprehensive rockfall hazard assessment strategy based on high-resolution terrestrial laser scanning is proposed. A high-resolution digital terrain model was obtained based on terrestrial laser scanning (TLS) and data processing. Combined with a three-dimensional (3D) probabilistic model, the movement of rock blocks is simulated, and the mechanical parameters for simulation are corrected by 3D back analysis. Finally, based on hierarchical analysis process (AHP) and raster calculation, a rockfall hazard map can be obtained. The method was applied to analyze rockfall hazards on the post-landslide rock slope in Ganluo County. It was found that the rockfall hazard of the post-landslide slope is a great threat to the personnel and equipment of the emergency rescue at the site, and its long-term rockfall risk is also a big hidden danger to the railway at the foot of the slope. The planned 3 m high and 1500 kJ energy capacity protection net has 87.22% interception efficiency, but it is difficult to stop the falling rocks with high speed or high bouncing height. According to the characteristics of rockfall hazards, recommendations for rockfall hazard mitigation measures are proposed, including two aspects of rockfall source area remediation and rockfall transport path blocking. The case of rockfall hazard assessment in Ganluo County provides new methods and ideas for the management of rockfall hazard on post-landslide rock slopes.