Consideration on the capture situation of open type steel sabo dams

Keisuke YOSHIDA, Joji SHIMA, Yasuhiro SATOU and Takeshi KADO


A debris flow along with driftwood occurred on September 10, 2015 in the Tamosawa watershed. The open type steel sabo dam named “Tamosawa Dai‐ichi” protected houses against the debris flow by trapping sediments and driftwood. We investigated the amount and the structure of the sediments and driftwood captured by the dam during the excavation work at the sedimentation area. In this paper, we reported the survey method of the captured sediments and driftwood, the estimated sediment transport characteristics from the investigation, the results of blockage condition of the opening part of the dam capturing debris flow mixed with driftwood, and the volume ratio of the captured driftwood to the planned total amount of out‐flow to the downstream.

Key words

open type steel sabo dam, debris, driftwood, trench excavation survey