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近年来,由于在堤坝溃决的早期预警、应预案编制以基于风的堤坝设计方法等中的重要作用,堤坝溃决问题日渐受关注.本文介绍了在验室堤坝溃决试验中观察的堤坝溃决冲刷过程以试验分析结果.共进行了5组堤坝溃决试验,其中4组的试验材料为不同掺混比例的沙-粉沙-粘土混合料,另外1组试验材料为沙.试验堤坝高75 m,坝顶宽60 cm.试验结果示,“陡坎”冲刷(溯源冲刷)在由粘性混合土料填筑的堤坝溃决过程中扮演着非常重要的角色.在试验中观察了水流切冲刷、溯源“陡坎”表层流化、由溃决洪水射流冲击引起的“陡坎”基和“陡坎”的土力学坍失稳等冲刷象.对于沙质堤坝,其溃决过程主要由水流切冲刷主,其下游坝坡逐渐地、比较均匀地后移.沙-粉沙-粘土混合料中的粘性土部分极大地缓了堤坝溃决冲刷的速度.
In recent years, due to the important role of wind-based dyke design method in the early warning of the bankruptcy of the dyke, the problem of dyke collapse has been paid more and more attention.This paper introduces the process of dyke collapse scouring observed in the laboratory dyke collapse test A total of five embankment dam tests were carried out, of which four groups of test materials were sand-silt-clay mixture with different mixing ratios, and the other one was sand.The test dam was 75 m high and the dam The top width of 60 cm.The test results show that the “steep ridge” scour (scouring erosion) plays a very important role in the process of bank dams built by viscous mixed materials.In the experiment, “Steep ridge ” surface fluidization, due to the collapse flood jet impact caused by “steep ridge ” base and "steep ridge The runoff scours the main stream, and its downstream dam slope gradually and relatively evenly moves backwards.The cohesive soil in the sand-silt-clay mixture greatly slows down the dam erosion.