In mountainous areas, infrastructures, roads and railways are subject to various natural hazards due to the gravitational phenomena. Beyond the danger to users, the consequences of traffic interruptions becomes, from an economic point of view, more and more problematic and it becomes essential to secure these itineraries. An existing method to protect against the rockfall is to set up rockfall barriers made by metallic nets. This thesis focuses on the study of the rockfall protection barriers made by metallic net developed by the company GTS. The net of these barriers is different compared to conventional systems by an orthotropic behavior, due to a special form of the mesh. In this study we characterize the behavior of these barriers under static and dynamic loading (impact) by an approach combining the experimentation and the numerical modeling. The study proceeds step by step, the components are evaluated in quasi-static, in laboratory, and also in-situ to simulate the real conditions of use, especially the dynamic aspect. A special attention concerning the energy dissipators, which represent the principal element of this structure, has enabled us to develop a robust and reliable fuse element. A campaign of full-scale tests on the studied rockfall barriers allows the validation of two energy classes (3000 kJ and 5000 kJ) according to the European recommendations. The data collected during experiments permits to develop various numerical models of finite elements and discrete elements. The relevance of the modelisation was evaluated at the different studied scales, the mesh scale, the net scale, the energy dissipators scale and the scale of the entire structure.
