Application of physical models to improve the mitigation structures of debris flow in a case study

Abstract

Debris flows are a phenomenon in mountains areas, where a large amount of mobile rock material, large amounts of water and steep slopes meet together. They are characterized by high capacity of sediment transport, high concentration of sediment with wide range of grain sizes and high front-velocity. To improve the protection measures against debris flow, it is necessary to know the processes of debris flows and its interaction with structures of the measures. By investigation of the mitigation structures in experimental scaled physical models it is possible to understand the functionality of the structures under different scenarios as well as optimization of the structures. For the protection of the counties Agarn und Leuk in Valais in Switzerland a multi-level debris flow basin system has been designed. By means the physical model in scale of 1:55 the functionality and the dimensions as well as the details of the structures could be optimized.