Capturing rockfall kinematic and fragmentation parameters using high-speed camera system

This paper presents a procedure for tracking rockfall trajectories and extracting kinematic parameters from both the impacts resultant fragments. A set of full scale experiments was performed in quarry located Vallirana, Barcelona (Spain). The study site chosen due to presence rigid discontinuity surface, inclined at 42° middle slope, whose configuration expected favor breakage blocks. blocks released fragments were recorded with three video cameras. C++ program specifically developed track 3D trajectory fragments, measure velocities before after impact. Two different modules implemented, one that break those do not. non-fragmented block is obtained by comparing it its model. In this way, center mass position orientation are tracked. For fragmented blocks, local coordinates determined images converted terrain using we developed. total 16 36 rock impact georeferenced linked common system terrestrial coordinates. captured allow obtaining velocity distribution coefficient restitution, energy balance break. To our knowledge, first attempt capture result full-scale tests. Although analysis fragmentation phenomenon beyond work, have compared performance unbroken purpose, built models generated drone. results indicate fragment show higher rebound coefficients restitution than not although there exists certain overlap between two groups. Despite experiment carried out on same surface small variations velocities, kinetic energies angles, present wide range values, who number tested too draw generalizable conclusions, but they highlight stochastic nature process necessity consider additional understanding. Finally, confirm relation dissipated and, especially new area created fragmentation. Furthermore, hit ground face generate most while vertex less.