Bridge obstruction caused by debris flow: A practical procedure for its management in debris-flow simulations

Bridge clogging due to a debris flow is a phenomenon scarcely studied but critical in hazard mapping in the mountain area. Since a rational and systematic approach is still missing, we propose a practical method to deal with this phenomenon in a numerical framework. We tested this methodology by using, as a numerical model, the two-phase, mobile-bed model TRENT2D and, as a site test case, the village of Voueces in the north-west part of the Italian Alps. The application shows reasonable results and highlights the importance of a mobile-bed approach.