Efficiency of Slit Dam Prevention against Non-Viscous Debris Flow

This paper describes an experimental work in order to assess the efficiency of slit dam on non-viscous debris flow. Some results have been acquired as follows: ① there are three kinds of blocking type: Total-blocking, opening and part-blocking. The blocking conditions of slit dam are closely link to b/d_ max （the ratio of slit width to maximum diameter of solid matter）, as b/d_ max is less than 0.739, the slit dam is total- blocking; and b/d_ max is more than 1.478, the slit dam will be opening; whereas b/d_ max ranges from 0.739 to 1.478, the slit dam is part-blocking. ② Variation of the mean density passing through slit dam is the most obvious as b/d_ max ranges from 0.739 to 1.232. ③ According to experimental results, slit dams have been shown to be effective in reducing debris flow density while slit density ∑b/B （B is slit dam width） ranges from 0.2 to 0.5.