川西高原冻融型高速滑坡特征与成因分析  

Characteristics and Cause Analysis of Freeze——Thaw Landslide on Western Sichuan Plateau

作　　者：李鹏岳[1] 铁永波[1] 王东辉[1] 唐业旗[1] 

机构地区：[1]成都地质矿产研究所,四川成都610081

出　　处：《水土保持通报》2014年第1期173-177,共5页Bulletin of Soil and Water Conservation

基　　金：公益性地质调查项目"西南山区地质灾害详细调查"(1212011140006);国家自然科学基金项目"冻融条件下冰碛补给型泥石流物源汇集机制研究"(41101086)

摘　　要：对于川西高原这类特殊环境下发育的滑坡,因其发生前无明显的滑动迹象,滑坡隐蔽性强,其危害性极大。这类滑坡在无地震和降雨作用情况下,因冻融作用使得上部岩体突然溃滑,继而转化为碎屑流,并沿途携卷铲刮坡体表层松散物质而产生高速运动,表现出与一般重力条件下滑坡不同的运动和堆积特征。以四川省德格县中扎科乡赵玛滑坡为例,对其发育特征及失稳过程进行了论述。根据滑坡的分区及动力学特征,将其失稳过程概括为孕育阶段,高速运动—碎屑化阶段和堆积阶段。结果表明,赵玛滑坡的运动速度最大可达75m/s,强烈的冻融作用以及滑坡区特有的地质构造是引起该滑坡高速远程运动的根本原因。研究结果可为川西高原因冻融过程诱发的滑坡灾害的防灾减灾提供理论依据。Landslide developed under the unique environment of Western Sichuan Plateau is characterized by strong concealment and hence is a kind of extremely serious disaster because of its less evident sliding indica- tion before occurrence. This kind of landslide often occurs suddenly due to freeze--thaw action, even in the absence of earthquake and rainfall, and then is transformed into debris flow. During its high speed movement, the landslide is capable of transporting and stripping loose materials on slope and therefore shows some movement and accumulation characteristics differing from common landslide by gravity. By taking the Zhaoma landslide in Zhongzhake Town, Dege County, for an example, development characteristics and fail- ure process of the landslide are analyzed. According to the division and dynamic characteristics of landslide, its failure process is generalized as the three stages of gestation, high-speed movement and debris flow, and accumulation. Results show that the maximum movement speed of the Zhaoma landslide is as high as 75 m/s and intensive freeze--thaw action and the unique geological structure of the study area are the primary causes for its high-speed remote movement. Result from the study may provide a theoretical base for prevention and reduction of the landslide disaster induced by freeze--thaw action on the Western Sichuan Plateau.

关 键 词：高速滑坡-碎屑流 冻融作用 成因分析 川西高原 

分 类 号：P642.22[天文地球—工程地质学]