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现代地质 ›› 2021, Vol. 35 ›› Issue (03): 744-752.DOI: 10.19657/j.geoscience.1000-8527.2020.034

• 水资源与环境地质 • 上一篇    下一篇

震后深切拉槽型泥石流成因模式、暴发特点与防治:以四川九寨沟牙扎沟为例

张卢明1(), 杨东1, 周勇1, 刘鹏2   

  1. 1.核工业西南勘察设计研究院有限公司,四川 成都 610061
    2.四川省冶勘设计集团,四川 成都 610081
  • 收稿日期:2019-05-21 修回日期:2020-05-06 出版日期:2021-06-23 发布日期:2021-06-24
  • 作者简介:张卢明,男,硕士,高级工程师,1982年出生,岩土工程专业,主要从事地质灾害方面的防治与研究。Email: zhangluming666@qq.com
  • 基金资助:
    国防科技工业局科研项目(科工二司[2015]548号);国防基础科研计划(咨国防[2017]1790号)

Genetic Model, Outbreak Features and Prevention of Post-seismic Deep-cut Trough-type Debris Flow: An Example from Yazhagou of Jiuzhaigou, Sichuan Province

ZHANG Luming1(), YANG Dong1, ZHOU Yong1, LIU Peng2   

  1. 1. Nuclear Industry Southwest Survey & Design Institute Co.,Ltd, Chengdu, Sichuan 610061, China
    2. Sichuan Metallurgical Geological Survey and Design Group Co.,Ltd, Chengdu, Sichuan 610081, China
  • Received:2019-05-21 Revised:2020-05-06 Online:2021-06-23 Published:2021-06-24

摘要:

以四川九寨沟地区牙扎沟泥石流为研究对象,通过数次野外调查及历史资料的统计,详细研究该泥石流的暴发特点、临界雨量及暴发成因,在成因模式分析的基础上提出相应的防治方案。研究结果表明:泥石流具有隐蔽性、突发性、破坏性和输沙能力较强的暴发特点;汶川地震后泥石流暴发的临界雨量仅为2008年“5·12”汶川地震前的一半,2014年至今流域未发生泥石流,临界雨量有逐渐恢复的趋势;短历时强降雨、深切拉槽式物源补给和高陡的地貌条件是泥石流暴发的根本原因;泥石流的成因模式为“降雨渗流、岩土饱水、山洪冲击、沟道深切拉槽、溯源侵蚀、冲刷淘蚀、岸坡侧蚀坍塌、悬移滚动”。这种震后 “拉槽”式泥石流治理应在提高设防标准和优化治理结构形式的同时,以控制集中区物源启动为主、拦挡为辅的防治思路为指导。研究结果可为该地区类似泥石流的防治及预警提供借鉴。

关键词: 深切拉槽泥石流, 成因模式, 暴发特点, 临界雨量, 九寨沟地区

Abstract:

Taking the Yazhagou debris flow in Jiuzhaigou earthquake area of Sichuan as an example, the outbreak features, the critical rainfall and the origin are studied in detail through geological surveys and historical data analysis. Based on the analysis of the formation cause, the corresponding prevention and control schemes are proposed. The results show that the debris flow is featured by being concealed, sudden, and destructive, with strong sediment transport capacity. The critical rainfall of debris flow outbreak is only half of that before the 12th May Wenchuan Earthquake, and no debris flow was reported in this area since 2014, indicating that the critical rainfall has a gradual recovery trend. Short bursts of heavy rainfall, deep-cut trough-type material supply, and elevated-steep topography are the root causes of the debris flow outbreak. The debris-flow genetic model includes the components of rainfall seepage, saturated rock and soil, mountain flood impact, deep-cut trough, headward erosion, scour erosion, bank erosion collapse, suspension and rolling. Controlling of Yazhagou debris flow in the earthquake area requires the protection standard and optimization of the control structure. Effective prevention and controlling method require mainly source control supplemented with debris obstruction. Our findings provide reference for the prevention and early warning of similar debris flows across the region.

Key words: deep-trough debris flow, genetic model, outbreak feature, critical rainfall, Jiuzhaigou area

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