磨西河泥石流堵断大渡河物理模拟与早期识别

发布时间：2018-04-09 21:33

本文选题：磨西河　切入点：泥石流　出处：《吉林大学学报(地球科学版)》2017年01期

【摘要】：历史记录与堆积区证据显示,四川泸定磨西河泥石流历史上堵断大渡河事件易发、频发,为泥石流堵河的典型案例。为了深入剖析磨西河泥石流相关物理参数对其入汇主河运动过程的影响,本文采用1∶500几何相似模型进行了物理模拟试验,结果表明:1)泥石流密度、流量比对泥石流堵河影响程度大,其均与泥石流堵河程度显著正相关,密度、流量比越大,堵河程度越严重,且存在发生堵河事件的临界点;2)流速比对堵塞影响程度小;3)磨西河堵断大渡河的早期识别指标为,当磨西河泥石流流量大于2 000 m3/s,泥石流物质组成为漂卵石混中粗砂、少含水时,磨西河泥石流易发生堵断大渡河的危害。磨西河泥石流堵断大渡河事件具有很强的偶然性与不确定性,本文仅选取磨西河与大渡河交汇区开展物理模拟试验,通过试验获取影响堵河发生的单因子临界值进行堵河早期识别,可能存在一定误差,但不失为堵河判别方法的创新,具有一定的实践意义,也为相关泥石流入汇主河早期识别理论与试验研究提供了技术方法。
[Abstract]:The historical records and evidences in the accumulation area show that the events of blocking and breaking Dadu River in the history of debris flow in Luding Moxi River in Sichuan Province are easy to occur and frequent, which is a typical case of debris flow and river shutoff.In order to deeply analyze the influence of the physical parameters of debris flow in Moxi River on the movement process of the main river, a physical simulation experiment using 1: 500 geometric similarity model is carried out. The result shows that the density of debris flow is 1: 1.The ratio of discharge to debris flow has a great influence on river shutoff, and both of them are positively correlated with the degree of mud-flow shutoff. The greater the density and the ratio of discharge, the more serious the degree of river shutoff.And there is a critical point for the event of blocking the river, the critical point is 2)) the ratio of velocity to velocity has a little influence on the plugging. 3) the early identification index of blocking and breaking Dadu River of Moxi River is: when the flow of debris flow in Moxi River is more than 2 000 m3 / s, the material composition of debris flow is medium coarse sand mixed with bleached pebble.When there is less water, the debris flow in Moxi River is liable to block and break the Dadu River.The event of debris flow blocking Dadu River in Moxi River has strong contingency and uncertainty. In this paper, only the intersection area of Moxi River and Dadu River is selected to carry out physical simulation test.There may be some errors in the early identification of river shutoff by obtaining the critical value of single factor affecting the river shutoff, but it is an innovation of the judgment method of river shutoff, which has certain practical significance.It also provides a technical method for the early identification theory and experimental study of debris flow entering the main river.
【作者单位】：西南交通大学土木工程学院;中国地质调查局成都地质调查中心;
【基金】：国家自然科学基金项目(41102226) 成都地质矿产研究所青年基金项目(2014-05)~~
【分类号】：P642.23

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