Abstract : The Structurally Dissipating Rock-shed (SDR) is a new kind of rock-shed. It is composed of a reinforced concrete slab supported by several metallic fuse supports. As opposed to the traditional rock-shed, the innovative SDR structure uses directly the slab motion and the deformation of slab and fuse supports to dissipate impact energy of rock blocks. This thesis aims to study SDR structural behaviour under rock blocks impacts and to improve the design of SDR structure. The structural analysis of SDR needs appropriate impact analyses. An impact algorithm was thus developed, which can resolve the unilateral impact problems between a rigid projectile and a soft structure. This impact algorithm has then been implemented in a finite element program. Validated by several tests, this development can be used for SDR structural analysis with account of the materials dynamic behaviour. This analysis tool has been used to model the SDR structure under different impact conditions. At first, the impact tests of a 1/3 scale SDR model are simulated in order to know the structure modelling feasibility. A satisfying correlation between the experimental and numerical results allows carrying out several sensitivity studies with respect to the mass and velocity of rock blocks, impact point position on the slab, thickness, concrete material and reinforcement ratio of the slab. At last, the full scale structural calculations are performed. All theses studies show the robustness of the SDR concept, and at the same time, the possible optimisations of the SDR structure, particularly for its punching shear resistance.