Quantitative investigation of sediment regulation performance of slot-check dam on viscous debris flow

Debris flow can be very destructive in densely populated and mountainous area. Slot-check dams are widely used artificial control works in the debris flow channel to alleviate the risk of debris flow disaster. However, the sediment regulation characteristics of slot-check dams for viscous debris flow which with a wide grain-size distribution remain poorly understood owing to the lack of reliable research. To quantitative explored the regulation performance of slot-check dams against debris flow, this study carried out a series of flume experiments. The results noted that the parameters of dam openings, bulk density of debris flow, and flume slope influenced the sediment regulation effect of the debris flow in varying degrees. To facilitate engineering application, a quantitative method for calculating the key parameters that reflects the regulation ability of slot-check dam against viscous debris flow was established, which considered the characteristic parameters of dam openings, debris flow, and gully. Moreover, the results revealed that the values obtained from empirical equations are in good agreement with the experimental values, which indicated that the empirical formula can be better applied to prediction. Finally, a quantitative design method of the opening parameters of slot-check dams was described using Shen gully as an example. Based on the results, the opening parameters are designed as the relative opening b/d max 1.5, the aspect ratio 1.8, and the aperture ratio λ 10%, which can provide the reference for the design of future debris flow mitigation works.