Debris flow impact on a flexible barrier: laboratory flume experiments and force-based mechanical model validation

Nowadays, hydrogeological instability is a very critical issue because of its impact on population, infrastructures and economic and productive sectors. This makes essential to use advanced and reliable defense technologies, which are able to guarantee high performance and reliability. Flexible and permeable structures are ideal for stopping natural phenomena like debris flow, thanks to their high deformation capacity and their water permeability. This study presents some results obtained from laboratory tests related to the impact of a simulated debris flow against a scaled physical model of the barrier. A granular flow composed of aggregates of known size particle was released in a channel with variable inclination and known length and height. Using this experimental setup, several tests were carried out by varying the inclination of the channel and the geometry of the barrier. The results obtained were correlated with data deriving from a simplified analytical model; the comparison between the measured and calculated values made possible to assess the good prediction capability of the model, providing a simple and innovative tool to design and assess the safety of deformable protection barriers.