Trapping large wood debris in rivers: experimental study on a novel debris retention system (article)

Abstract

Large wood debris can cause critical damage to bridges and other riverine structures, and increase flood risk. Although their effects on hydrodynamic actions and flood levels have been investigated in recent research, little effort has been devoted to reducing the amount of debris that can accumulate at structures. This paper proposes and experimentally tests a new type of large wood debris retention system in which a series of alternating porous and rack-type modules, is placed in-line with the current. Laboratory tests illustrate that the proposed retention system can offer high levels of efficiency in trapping large wood in rivers. The geometrical features of the structure are observed to play a major role and can be carefully chosen to optimise trapping efficiency. Results also show that large wood debris trapped by these structures have limited effects on the increase of the upstream water levels. Further development of the solution proposed in this work can pave the way for use of low-cost, highly-effective debris retention systems for effective river management and large wood debris removal in practice.