On the evaluation and modelling of wood clogging processes in flood related hazards estimation

Abstract

The topic of the present paper is the quantification of the processes of bridge clogging by wood and its consideration in natural hazards assessment. Physical, scale model tests on bridge clogging were conducted in the hydraulic laboratory of the University of Innsbruck. Clogging probabilities were analyzed within a comprehensive set of experimental tests. The characteristics of critical configurations of wood loading, hydraulics and bridge type/structure are illustrated. A synopsis of results from previously conducted tests on this topic show that quantifying such a process should be carefully done, due to the apparent randomness of the wood motion in the channel and at the bridge. Nevertheless, the consideration of wood clogging at vulnerable structures is an essential part in flood related hazards assessment. Wood clogging affects not only the structure itself, but also floodplain inundation in the vicinity of these structures resulting into higher flood risk.