Numerical simulation of rockfall trajectory with consideration of arbitrary shapes of falling rocks and terrain

This paper proposes a 3D model for analyzing the rockfall trajectory within the framework of contact mechanics and rigid body dynamics, focusing on arbitrary shapes of the falling rock and terrain. Firstly, the sphericity and the concavity and convexity are defined to quantitatively describe the overall shape and local appearance of often-observed falling rocks, respectively. A generation algorithm is then proposed to generate falling rock and terrain with arbitrary shapes. The surfaces of the generated falling rock and terrain model are both meshed by triangular elements. A contact searching algorithm as well as a bilinear model for contact collision are presented to solve the interaction between the falling rock and terrain. Validated by available field test data, it is demonstrated that the proposed approach could simulate the four motion modes of rockfall such as falling, bouncing, rolling and sliding, as well as the transition between them.