川西高原的岩土体的冻融破坏类型及其灾害效应

Damage Types and Hazards Effects from Freezing-Thawing Process in Plateau of Western Sichuan Province

[目的]探明川西高原冻融过程对岩土体的破坏类型、成因机制及其产生的灾害效应。[方法]通过对川西高原道孚县全县境内的地质灾害详细调查,对冻融破坏类型进行了室内统计分析,并在此基础上总结了冻融过程所产生的灾害效应。[结果]提出了冻融过程产生"剥皮效应"、滑坡的"浅表层效应"及泥石流物源的"碎化效应";发现川西高原上的泥石流流体携带块石含量较少且粒径多小于1m,其成灾模式多以於埋破坏为主;县境内约70%的滑体厚度小于20 m滑坡,多以浅层小规模为主,危害相对较小。[结论]道孚县境内发育的泥石流具有相对较弱的冲击力,防治时应以疏导工程为主;道孚县境内发育的滑坡具有规模相对小的特点,且易在冰雪融水或降雨作用下产生滑动,地表排水对其稳定性的维持极为重要。

[Objective]To Study the damage types and hazard effects from freezing—thawing process and the mechanism of geo-hazards/soil erosion in plateau of Western Sichuan Province.[Methods]On the basis of the specific survey of geological hazards in Daofu County of the plateau of Western Sichuan Province,the hazard effects of freezing and thawing were analyzed and summarized,and different damage types were counted.[Results]We put forward several damage effects as the ＂peeling effect＂of freezing—thawing,the＂surface effect＂of landslide and the＂fragmentation effect＂of debris flow source.The carried stones of debris flow were less than 1 min diameter.Therefore,burying was the main damage type of debris flow.More than70% of landslides had the depth less than 20 m,the volume of these landslides were relative smaller,and the potential hazards from landslide is lower.[Conclusion]The damage power from debris flow in the plateau of Western Sichuan Province is weak,the prevention engineering should be consider as drainage oriented types.The landslide in the plateau of Western Sichuan Province had small volume,and this type landslide can slide easily under the lubrication of snow melt water or rainfall,and keep the slope flow away from landslide is important to the stability of this type of landslide.