Dynamic Behavior and Deposit Features of Debris Avalanche in Model Tests Using High Speed Photogrammetry

Model tests of debris avalanche can not only illuminate formation mechanisms but also represent deformation and motion processes. At present, the static terrain data of model tests are measured before and after experiments using terrestrial laser scanning. To study the motion and deformation of research objects, it is necessary to explore new techniques to obtain dynamic terrain data in the course of experimentation. In this paper, taking specified experimental tests of debris avalanche as an example, the method of 4D reconstruction using high-speed close-range photogrammetry is described in detail. The dynamic terrain data of model tests were obtained after the data were processed. Then, the dynamic behavior and deposit features of debris avalanche were analyzed in detail. Results show that dynamic terrain data of model tests can be obtained rapidly and accurately with this method. The propagation and deposit processes of the debris avalanche have evident stage characteristics, which can be divided into the starting, acceleration, constant, and deceleration stages. The granular size, slope angle, and barrier effect have a great influence on the travel distance and duration of the debris avalanche. The depth of the intermediate and leading area of the debris avalanche increased gradually and the depth of the trailing area first increased then decreased. We believe that this approach can also be applied to other domains involving the acquisition of dynamic terrain data and, thus, deserves to be applied widely.