Game-Engine Based Rockfall Modelling: Testing and Application of a New Rockfall Simulation Tool
Rockfall presents an ongoing challenge to the safe operation of transportation infrastructure across Canada, creating hazardous conditions which can result in damage to roads and railways, as well as loss of life. Conventional rockfall risk assessment frameworks involve the determination of several pieces of information relevant to hazard management including where rockfalls might come from, how frequently they will fall, and how large the falls will be. Another important piece of information is the likelihood that a given fall will reach the road or railway. One method of estimating this likelihood is the use of rockfall runout programs which simulate the 3D trajectories of volumes of falling rock. The focus of this research is the development and testing of a new rockfall simulation workflow which uses the Unity3D game engine and other complimentary 3D modelling software packages. The simulation method developed has been applied to two different rockfall field studies from the literature, one in Ehime Japan, and one in the Port Hills region of New Zealand. Rockfall runout information collected at these sites including translational and rotational velocity, and deposition location, has been used to test the ability of our technique to simulate rockfall trajectories which are realistic compared to rockfall events on real slopes. A parametric investigation into the various inputs necessary to setup a basic rockfall simulation was also completed in order to identify any key sensitivities in the model. The workflow necessary to produce 3D rockfall simulations using Unity3D is outlined. The technique is capable of simulating the trajectories of multiple moving fragments at once and supports the use of high-resolution 3D geometry extracted from remote sensing datasets. Using this workflow five fragmental rockfall events from our field study sites in South-Central, British Columbia were simulated. The results of this work demonstrate the capability our rockfall simulation tool to model complex rockfall scenarios using high-resolution (<10 cm) terrestrial laser scanning inputs.