冲刷过程中岸坡条件对塌岸淤床交互作用影响的试验研究  

Experimental Study of the Influence of Bank Conditions on Bank Failure and Interaction with Riverbed Deformation During Scouring Process

作　　者：胡呈维 余明辉[1] 魏红艳[1] 吴松柏[1] 

机构地区：[1]武汉大学水资源与水电工程科学国家重点试验室,湖北武汉430072

出　　处：《工程科学与技术》2017年第2期77-85,共9页Advanced Engineering Sciences

基　　金：国家自然科学基金重点资助项目(51339001);国家自然科学基金资助项目(11472198)

摘　　要：天然情况下,不同的岸坡坡度及岸坡土体组成将会共同影响岸坡稳定性及崩岸的发生。本文在弯道水槽中开展系列试验,分析不同的岸坡条件对岸坡稳定性以及崩塌体与河床交互作用所产生的影响。试验结果表明:岸坡崩塌及崩塌体的分解输移与近岸水流的紊动能关系密切。水流冲刷过程中岸坡破坏是水流淘刷岸坡坡脚、岸坡崩塌及崩塌体淤积坡脚并在河床上输移的反复循环过程,无论岸坡是黏性土组成还是非黏性土组成,坡脚附近河床并没有与崩塌土体发生掺混。在岸坡形态、河床组成及水力条件相同的情况下,黏性岸坡坡脚处河床冲刷量明显大于非黏性岸坡坡脚处河床冲刷量;黏性岸坡崩塌量小于非黏性岸坡崩塌量。在岸坡材料相近、河床组成及水力条件相同的情况下,较陡岸坡经水流淘刷后更易失稳,岸坡冲刷崩塌量及崩塌物质在河床上的淤积量明显大于较缓岸坡情况。研究结果初步揭示了不同岸坡条件对塌岸淤床交互作用的影响,可用于指导河道岸坡防护及河道整治规划。Naturally, different bank slope and bank soil compositions can have a combined effect on bank stability and failure. A series of experiments were carried out in a bend flume to study the influence of different bank conditions on bank stability and the interaction between the landslide materials and bed evolution. Experiment results show that bank erosion,the disintegration and transportation of a collapsed bank block and the mixing between the soil and bed evolution have a close relations with turbulence energy near the bank. Bank erosion is a process of repeated interaction between bank toe scouring and bank collapse along with the deposition and transporta- tion of landslide material. Whether the bank soil is cohesive or not, there exists no mixing between riverbed near bank toe and collapsed bank block. With the same bank configuration, riverbed compositions and hydraulic conditions, riverbed scouring volume near the cohe- sive bank toe is larger than the one near the non-cohesive bank. The erosion volume of cohesive bank is smaller than that of the non-co- hesive bank. With similar bank material and the same riverbed compositions and hydraulic conditions, steeper bank is prone to greater instability under water action. The erosion volume and the silting volume of bank-failure materials on the riverbed for the bank with steeper slope are larger than those for the bank with milder slope. The results can be used to guide the protection of bank erosion and fiver regulation planning.

关 键 词：河岸边界条件 岸坡崩塌 河床演变 水力冲刷 水槽试验 

分 类 号：TV122[水利工程—水文学及水资源]