Towards Reliability-Based Design of rockfall hybrid barriers and attenuators: a focus on the actions

The conventional design approach for geotechnical structures presented in Eu-rocode 7 (EC7) shows limitations when dealing with rockfalls. To overcome these limitations, we propose the application of Reliability Based Design (RBD), which describes the relationship be-tween the actions and the system's resistance. RBD is a fully probabilistic approach: each param-eter is described by a Probability Density Function (PDF). Considering the application of the RDB approach to new hybrid barriers and attenuators, this paper will focus on the description of the actions. To describe the rockfall process, two main parameters are identified: Total Kinetic Energy (Ek) and position of impact on the structure. This works shows how by employing robust statistical approach and a large set of numerical simula-tions it is possible to define the Cumulative Distribution Functions (CDFs) of these parameters. Then, using proper statistical tests, the best-fitting PDFs can be identified and employed in the RBD design approach.