A New Simulation Tool on Rockfall Fragmentation-Movement-Deposition Process

Fragmental rockfall occurs frequently in an alpine region of Southwest China, causing a huge number of hazard fatalities and property losses. So far, the current simulation methods are hard to demonstrate the integrated fragmentation-movement-deposition process in a fragmental rockfall event, due to the complex physics mechanism and lack of precise data. Particularly, it happens in a three-dimensional environment. Herein, we present a new simulation tool using the PhysX physics engine to provide a rapid simulation method on rockfall movement including the complex impact process of fragmentation, movement and deposition. The different movement types, e.g., sliding and rolling, are validated by the tool compared to the theoretical formulas. The unmanned aerial vehicle (UAV) is used integrated with a LiDAR camera to collect the high-precision slope surface model. Blender, an open-source software, is used to build the unstable rock mass model. Then, both the slope surface model and rock mass model are imported into the Unity 3D platform to carry out the rockfall movement process. The case application that occurred at the Emei-Panzhihua Railway K279 + 350 on rockfall movement simulation was presented to validate this method in practical use. The trajectory, velocity, energy and jumping height of each fragment can be recorded and output in tabular form for the risk assessment and engineering design.