Rockfall Trajectory Analysis with Drapery Systems

Abstract

This work presents some recent developments on the experimental and numerical analysis of rockfalls involving a simple drapery system. Since blocks can still detach in between the installed drapery and the rock surface, an accurate prediction of the trajectories and residual energies at the base of such slopes is essential. Experimental results of full scale tests carried out at a mine are presented where concrete blocks were released from the top of a highwall. Video analysis based on stereo-photogrammetry allowed the 3D trajectories and 3D velocities of the block to be measured. The information gathered during the experimental testing was then used to calibrate and validate a newly developed 3D numerical model. The model is based on the discrete element method and implemented into the open-source framework YADE. All relevant interactions between block, drapery and slope are taken into account. The model allows the 3D trajectories and 3D velocities of rockfalls with draperies to be accurately predicted. Finally, the capabilities of the model are discussed and it is used to predict trajectories for various block shapes.