Rockfall shelters covered by granular layers. Experiments and design approach

This paper describes an uncoupled approach for the design of rockfall protection tunnels. More precisely, this approach concerns tunnels covered by soil layers, and it derives from the interpretation of real scale tests. Within this approach tools are provided for evaluating the impact force acting at the boulder-soil interface and for describing the propagation of stresses through the soil stratum. The experimental basis and the modelling tools are described in dedicated sections. Engineering considerations about the dynamic excitation of the sheltering tunnel are also suggested on the basis of the behaviour observed during experiments. Finally, a section is devoted to an application of the method.