Research on the failure mode and kinematics of high-steep rock slides based on video target tracking: A case study of Bijiashan rock fall in Wu Gorge in the Three Gorges Reservoir area, China

Abstract

Analyzing the failure mode and kinematics of high-steep rockslides and rockfalls is crucial for a comprehensive understanding of their instability mechanisms. Existing methods for determining the failure mode and kinematics of rockfalls either rely on large-scale outdoor experiments or involve basic video analysis. This paper proposed a flexible method for analyzing the failure mode and kinematics of high-steep rockfalls based on video target tracking, which is applicable to videos shared on online media platforms. The Bijiashan rock fall (BRF) event that occurred in the Three Gorges Reservoir area (TGRA) in China on September 28, 2021, was selected as the study case. Through video target tracking and coordinate correction, the failure mode and kinematic characteristics during the collapse process of the BRF were obtained. The rock mass in source area was segmented into three zones, top, middle, and base. The failure mode was described as that the base rock mass underwent buckling and disintegration, resulting in the middle rock mass losing balance and sliding, ultimately leading the top rock mass to fall off. During the rock slide, the largest falling rock's mass was estimated to be 37.7 kt, with an impact velocity of 51.2 m/s and an impact kinetic energy of up to 49.4 × 10⁶ kJ. This study can serve as a reference for future research on understanding the failure mode and kinematics of high-steep rock slides using video target tracking tools.