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。
According to historical records and the evidence of accumulation area,Dadu River blocking due to Moxi River debris flow happen easily and frequently in history,it＇s a typical case of debris flow blocking the river.For analyzing the movement of debris flow confluence with the main river and the effect of key parameters deeply,in this paper,the physical simulation experiment was carried out by using 1∶500geometric similarity.And some conclusions are drawn as the followings.Firstly,the bulkdensity and flow rate of debris flow is the major impact on the debris flow blocking the main river,and there is a critical point for the occurrence of the river blocked.Secondly,the influence of the speed ratio is small.Secondly,the main factor for the debris flow blocked the Dadu River is bulk density,flow ratio,and there is a critical point for the occurrence of the river blocked.And finally,the early identification index of Dadu River blocking due to Moxi River debris flow is obtained.When the Moxi River debris flow is greater than 2 000 m^3/s,material composition is medium-coarse sand mixed with drifting pebbles and thick,Dadu River is blocked easily due to Moxi River debris flow.The experiment and conclusion has practical significance to secondary disaster chain disaster prevention and mitigation of Moxi River debris flow.It also provides a technical method for the early identification of debris flow confluence with the main river and the experimental research.
作者
宋志
邓荣贵
陈泽硕
冯伟
Song Zhi Deng Ronggui Chen Zeshuo Feng Wei(School of Civil Engineering, Southwest J iaotong University ,Chengdu 610031, China Chengdu Center of China Geological Survey,Chengdu 610081, China)
出处
《吉林大学学报（地球科学版）》
EI
CAS
CSCD
北大核心
2017年第1期163-170,共8页
Journal of Jilin University：Earth Science Edition
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)~~
关键词
磨西河
泥石流
物理模拟
早期识别
Moxi River
debris flow
physical modeling
early identification
