COMPUTATION ON SUBMERGED LARGE WOOD BEHAVIOR AROUND A DRIFTWOOD TRAPPING FACILITY

Abstract

 We conducted a study using a 3D-type numerical analysis model on inlet type driftwood capturing facility. Since the specific gravity of the target broadleaf tree exceeds 1, it moves near the river bed with effect of the bed friction. In the numerical model, a bed friction term between the bed and driftwood is introduced, and the rolling movement of the driftwood is considered. We introduced a frictional force anisotropy model to reproduce the sliding and rolling motions. For the collision of driftwoods, the collision force was evaluated with the distinct element method (DEM). As a result of applying the numerical analysis model to the previous experiment by Kato et al. it was confirmed that this model can reproduce the driftwood behavior around the capturing facility in reasonable accuracy.