EXPERIMENTAL STUDY ON SEGREGATION PHENOMENON OF WATER, SEDIMENT, AND WOOD USING LARGE SIZED BALL MILL DEVICE

Abstract

 A steel pipe open Sabo dam has been constructed as a countermeasure structure against debris flow. In the event of debris flow, boulder and driftwood block the permable part of the open Sabo dam, trapping the following sediment. This is because the boulder and driftwood are concentrated at the front part of debris flow. However, the mechanism of this occurrence is still unclear in many points, and there is still little research on driftwood, which has been a trend in recent disasters. This study investigates the conditions for the occurrence of classification phenomena in mixture of water and sand, water and driftwoods, sesiment and driftwoods including water using a ball mill device. The results is shown that driftwood generates classification phenomena by water and sand circulation.