INVESTIGATION OF THE EFFECT OF TRAPPING DEBRIS FLOW OF OPEN CHECK DAMS WITH CONVEX STEEL FRAMES BY USING HIGH-RESOLUTION SIMULATIONS OF DEBRIS FLOW INCLUDING DRIFTWOOD

Abstract

 This paper presents a new type of check dam that has a convex steel frame to the upstream side. To examine the effects of trapping debris flow of the proposed dam, a new numerical simulation was developed that was capable of predicting the interaction of debris flow including driftwood and the steel frame. The numerical simulation of the debris flow occurred in Hiroshima in 2014 was performed by the developed model where the debris flow impacted against three dams of different types (a closed-type dam, an open dam with a straight frame and an open dam with a convex frame). The results of the simulations showed that the check dam with the convex frame trapped roughly 30% more debris flow than the colosed-type dam did. It was confirmed that the convex frame of the check dam was an effective structure for trapping debris flow.