INTEGRATED INVESTIGATION INTO WOOD ACCUMULATION AT BRIDGE AND A WEIR

Abstract

 This study examined the relationship between local hydraulic characteristics and wood accumulation probability at river structure by integratedly treating bridge and a dam/weir. Specifically, after quantifying the wood accumulation probability by experiments, the dimensionless hydraulic quantities involved in the wood accumulation probability were extracted by the consideration with the aid of three-dimensional computational fluid dynamics. As a result, two dimensionless quantities representing the effects of the contraction velocity at the structure and the approach flow velocity were extracted as the dominant dimensionless hydraulic quantities. The results implied that wood accumulation probability at dams/weirs is lower than that at bridge piers because dams/weirs have comparatively large values of the involved two dimensionless quantities owing to the flow acceleration for the free surface overflow.