Towards a codified design procedure for rockfall reinforced earth embankments

Rockfall protection embankments are compelling mitigation measures for those situations involving very high kinetic energy or large blocks and where the slope toe is almost flat. Several systems have been developed, and, among them, reinforced earth embankments allow considerable heights and inclination of the faces up to 70°. Nevertheless, a common procedure for including the dynamic condition, i.e. the impact, against such structures has not been delineated yet, and also the existing European Standards do not define a unique procedure. This work aims at defining a design flowchart in agreement with the Eurocodes, encompassing verifications both in static and seismic conditions and in dynamic one, i.e. when a block impacts against the structure. All the failure scenarios are considered and the embankments have to be designed first to intercept blocks. Considering the impact, an energy approach is suggested to assess the stability of the structure and a procedure to determine the displacements occurred at the impact is herein delineated. With a simple analytical solution, herein explained, the percentages of energy dissipated at the impact by plasticization or friction can be derived and used to evaluate the displacements.