3D Rock Structure Digital Characterization Using Airborne LiDAR and Unmanned Aerial Vehicle Techniques for Stability Analysis of a Blocky Rock Mass Slope

Abstract

Airborne light detection and ranging (LiDAR) and unmanned aerial vehicle-structure from motion (UAV-SfM) provide point clouds with unprecedented resolution and accuracy that are well suited for the digital characterization of rock outcrops where direct contact measurements cannot be obtained due to terrain or safety constraints. Today, however, how to better apply these techniques to the practice of geostructural analysis is a topic of research that must be further explored. This study presents a processing procedure for extracting three-dimensional (3D) rock structure parameters directly from point clouds using open-source software and a three-dimensional distinct element code-assisted (3DEC) simulation of slope failure based on carbonate rock cliffs in the Jiuzhaigou Scenic Area. The procedure involves (1) processing point clouds obtained with different remote sensing techniques; (2) using the Hough transform to estimate normals for the hue, saturation, and value (HSV) rendering of unstructured point clouds; (3) automatically clustering and extracting the set-based point clouds; (4) estimating set-based geometric parameters; and (5) performing a subsequent stability analysis based on rock structure parameters. The results show that integrating different remote sensing techniques and rock structure computing can provide a quick way for slope engineers to assess the safety of blocky rock masses.

Review of Photogrammetric and Lidar Applications of UAV

“…They acquired approximately 1700 images, from which they produced digital surface models (DSM) at three different scales: a large-scale DSM of the entire road, a medium-scale DSM to assess parts of the slope, and a small-scale DSM to assess individual discontinuities. The publication [158] used an AS350 helicopter with a Leica ALS80-HP airborne lidar system and a DJI Phantom 4 RTK UAV with an FC6310 camera (1" CMOS) to monitor slope disturbance in the Jiuzhaigou area. Point clouds using lidar were acquired from a flight height of 1500-3000 m AGL, and 377 high-resolution images were acquired using the DJI UAV Phantom 4 RTK, where a dense point cloud was made.…”

Rockfall Analysis from UAV-Based Photogrammetry and 3D Models of a Cliff Area

“…These technologies precisely identify location-dependent rock structures by analysing point clouds. Numerous studies have highlighted the benefits and constraints of employing remote sensing ASL and TSL techniques to identify, characterise, and monitor rockfall sources at different scales [28][29][30][31][32][33].…”

Three-Dimensional Rockslide Analysis Using Unmanned Aerial Vehicle and LiDAR: The Castrocucco Case Study, Southern Italy

“…[39] and references therein). Turning specifically to rock landslides, UAV photogrammetry and LiDAR are particularly useful for detecting source areas, extracting discontinuity and joint families, computing the volumes of involved rock masses, and modeling block trajectories [40][41][42][43][44].…”