Experimental and Numerical Impact Responses of an Innovative Rockfall Protection Structure Made of Articulated Concrete Blocks

This study deals with an innovative type of protection structure for gravity-driven natural hazards such as landslides (slope failures, rockfalls, etc.) consisting of a vertical wall made up of interconnected concrete blocks. This type of articulated structure presents many advantages including reduced footprint, versatility and easy maintenance. The response of such a structure under impact is investigated considering projectiles with kinetic energies of 520 and 1020 kJ, based on real-scale impact experiments and numerical simulations. The finite difference model is described in detail as well as the experiments. The model was developed focusing on the global structural impact response while keeping the computation time reasonable. The model parameter calibration is based on data in the literature and complemented with specific measurements. The experimental data allows us to describe the impact response of the structure and identify the main mechanisms controlling this response (sliding, tilting, and fracturing). The simulation results revealed that the model is efficient in mimicking this response, in terms of deformation amplitude and evolution with time. Finally, the numerical model made it possible to highlight complex mechanisms that were not possible to experimentally determine such as the different energy dissipation modes within the wall. Highlights Full-scale impact experiments demonstrating the impact strength of articulated walls made of concrete blocks and metallic elements up to 1000 kJ. Finite difference model of the structure validated against experimental data. Highlights of the prevailing mechanisms involved in the impact response of the structures based on both numerical and experimental investigations. Based on simulation results, friction between concrete blocks and damage to concrete contribute up to 70% of the projectile kinetic energy.