The contribution of continuum-mechanics based numerical model to the design of debris flow barriers

The correct estimation of the dynamic impact of the front of a debris flow against a structure is a key phase of its design procedure. In fact, although the dynamics of fluid-structure interaction is not completely understood yet, its role must be carefully evaluated to determine the possible ultimate limit states of the structure under impact. In this paper, with reference to the debris flow phenomena that periodically occur in the basin of the Grand Valey torrent (Aosta Valley Region, Italy), the RASH3D code, based on a continuum-mechanics approach, has been used in order to show the contribution that such models can give in determining the dynamic parameters useful in defining the dynamic actions needed to assess the safety of defence structures, like check dams.