Impact of falling rock blocks on metallic structures: contact law and dynamic response

This study presents the dynamic structural response of a steel member subjected to a localized impact arising by falling blocks in mountainous regions. Different contact models are considered for the interaction between the metallic member (the target) and an impacting spherical rock block. A simplified SDOF analytical model accounting for nonlinear contact interaction and material nonlinearities has been used to describe the dynamic response of the steel member. For validation, the investigated contact laws and the dynamic analytical model are compared with more detailed static and dynamic analyses conducted with finite element software Ansys. The results are compared and commented in order to be implemented in future civil engineering design calculations. As a possible application, the study of the impact of a falling block against a planar metallic truss, e.g., a power line tower is proposed. The uncertainties related to size, velocity and material characteristics of the rock blocks are considered in the simulations.