2008 Volume 52 Pages 139-144
Debris flow is a phenomenon that high-density water with mud and big gravel flows down along a stream at high speed. Because of its high density and speed, it has huge destruction power. Thus damages by debris flows are very severe and sometimes tragic. A check dam is commonly used for preventing the sediment disaster due to debris flow by storing the harmful sediment discharge and has various types. Numerical simulations and experiments have been carried out to investigate the mechanism of debris-flow deposition process upstream of a check dam, and flushing out of deposited sediment due to erosion process by a normal scale flood flow. The simulations and experiments have been performed using closed type and grid type check dams. The simulated results agree well with the experimental results. From the results, it is shown that the grid type check dam can keep their sediment trapping capacity more effectively than the closed type check dam.
