NUMERICAL EXPERIMENTS ON ACCUMULATION PROCESS OF DRIFTWOODS AROUND PIERS BY USING A DEM-FLOW COUPLING MODEL

Abstract

A numerical simulation method has been developed for describing the behavior of driftwoods motion and their accumulation process in channels with bridge piers. The present model has been composed of Eulerian analysis of depth-averaged flow motion and of Lagrangean analysis of driftwoods motion by using the extended Distinct Element Method (DEM), which can simulate the motion of driftwoods as the rigid body. The calculation results show time-depending process of driftwood accumulation in front of bridge piers including the effect of branch shape of driftwoods and also show the amount of dam-up water level due to jamming of driftwoods.