Experimental study on characteristics of trapping and regulating sediment with an open-type check dam in debris flow hazard mitigation  

作　　者：SUN Hao YOU Yong LIU Jin-feng 

机构地区：[1]Key Laboratory of Mountain Hazards and Earth Surface Process,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Mountain Science》2018年第9期2001-2012,共12页山地科学学报（英文）

基　　金：supported by the Chinese Academy of Sciences and Organization Department of Sichuan Provincial Party Committee“Light of West China”Program(the key control techniques of glacial debris flow along the Sichuan-Tibet Railway);the National Natural Science Foundation of China(Grant No.41772343);STS Project of the Chinese Academy of Sciences(KFJ-STS-ZDTP015)

摘　　要：Beam dams are a highly effective and commonly used open-type check dam in debris-flow hazard mitigation. In this study, dimensional analysis was used to obtain empirical equations for quantitatively determining the sediment-trapping and flow-regulating characteristics of a beam dam. To determine the coefficients of the empirical equations, flume experiments were conducted to simulate the trapping and regulating processes. The flow pattern, trapping, and regulating characteristics were investigated when debris flows passed through a beam dam. Debris-flow bulk density and peak discharge, and sediment-trapping ratios, were measured directly and indirectly. The results showed that three blocking actions occurred, and that blockage-breaking considerably influenced the trapping and regulating performance of the beam dam. The relative opening size and the sediment concentration were the two main factors affecting the performance of the beam dam. The ratio of trapping sediment decreased with relative opening, and increased with sediment concentration as well as reducing ratio of bulk density and reducing ratio of peak discharge. The sediment concentration and relative opening were the leading factors influencing the trapping and regulating sediment of a beam dam, followed by flume gradient. The results showed that the calculated values obtained using empirical equations were in good agreement with the values derived from the experiments, and that the deviation was acceptable. Finally, taking Zechawa Gully as an example, using the empirical equations we designed the opening size of a beam dam aimed to trap sediment and regulate peak discharge of debris flow in the main gully.

关 键 词：Debris flow Beam dam Flumeexperiment Trapping and regulating 

分 类 号：P642.23[天文地球—工程地质学]