Experimental Verifications and Applications of 3D-DDA in Movement Characteristics and Disaster Processes of Rockfalls

Rockfalls are a major hazard in mountain areas and along engineering slopes. It is important to fully understand the characteristics and processes of rockfall movements, both for hazard assessment and countermeasure design. This study focused on the movement characteristics and disaster processes of rockfalls by three-dimensional discontinuous deformation analysis (3D-DDA), the effectiveness of which was verified by outdoor experiments. An apparatus specifically built for the experiments was established, which included a releasing device and a binocular camera stereovision system. Blocks of three different shapes and sizes were released on slopes with three different inclinations on the campus of Tibet University. The indices of the movement characteristics of the blocks, such as lateral deviation, resting position, jumping height, and kinetic energy evolution, were investigated. The experimental results were compared with those of the 3D-DDA, so as to study the rockfall movement characteristics. On this basis, the 3D-DDA was applied to simulate a large-scale slope rockfall on the Tibetan Plateau, and the rockfall failure processes and movement characteristics were further analyzed. The results showed that the 3D-DDA method could effectively simulate the entire rockfall process in time and space, including instability and movement. Through the 3D-DDA numerical simulations, rockfall phenomena and behaviors could be fully understood. Furthermore, by analyzing the trajectories and kinetic energies of a rockfall, the prediction of rockfall disasters and the reasonable design of protective countermeasures could be realized.