VIDEO IMAGED BASED ANALYSIS OF MOTION CHARACTERISTIC FOR TOWER ROCK COLLAPSE

Tower rock has a kind of common potential geohazard in limestone mountainous area of southwest China. This type of rocks is widely distributed and prone to be damaged. Their collapse can be induced by many factors. Taking Zengziyan perilous rock as example, this paper presents a detailed analysis of the process of tower rock collapse. The analyses of the collapse and especially for its motion characteristic are based on video data. The process of Zengziyan perilous rock collapse can be divided into three motion phases: startup phase, acceleration phase and collision phase. The failure begins at the bottom of tower rock. During the falling process, some features such as cracks propagation and damage transfer from the bottom up are taking place. The acceleration curve of Zengziyan tower rock shows a continuous negative fluctuation similar to buffering in declining stage. And motion characteristic curves of different monitoring locations have significant differences with time, which indicates that there are rupture, collision and disintegration synchronously when the tower rock falling.