Experimental study on the characteristics of a debris-flow drainage channel with an energy dissipation structure

Experimental tests were conducted on a drainage channel with an energy dissipation structure and four channel slopes. Differences in the drainage channel were observed when the debris flow passed the energy dissipation structure. Additionally, the time-averaged debris-flow depth at the energy dissipation structure section was 1.78 times deeper than those in the upstream and downstream locations of the energy dissipation structure and the locations through the smooth drainage channel. Moreover, the time-averaged velocity downstream of the energy dissipation structure gradually increased with increasing channel slope and gradually decreased with increasing energy dissipation structure length. Changes in the channel slope and energy dissipation structure length produced a minimum time-averaged velocity that was 0.50–0.74 times the maximum time-averaged velocity. Furthermore, the energy dissipation ratios gradually increased with an increasing area of the energy dissipation structure, which increased gradually with increasing channel slope and then decreased slightly. The maximum energy dissipation ratio was obtained at the channel slope i = 25 %, and the minimum and maximum energy dissipation ratios were 3.2 and 69.5 %, respectively.