EXPERIMENTAL STUDY ON DEBRIS FLOW CAPTURING PROCESS OF GRID TYPE SABO DAM

Abstract

The debris flow capturing process of the grid type sabo dam was clarified experimentally. The process could be explaned as follows; the dam was blocked by debris flow and the sediments deposited upstream of dam. The blocking was affected by the three-dimensional interlocking of gravel near the open spaces. After the blocking of dam, the incoming debris flow jumped due to the collision with the deposited layer. Then, the jumped sediments were divided into the sediments which got over the dam and the ones which returned back and deposited. Then, incoming debris flow ruched over the dam accompanying with the erosion of deposited layer. The debris flow discharged from dam and deposited upstream of dam intermittently by such a process. The separation of sands and gravels occurred by the deference of repulsion force in the process of debris flow jumping and the gravels deposited above sands, that is, the reverse-grading phenomenon of deposition.