库水位升降作用下不同滑面形态老滑坡响应规律  

RESPONSE PATTERNS OF OLD LANDSLIDES WITH DIFFERENT SLIPSURFACE SHAPES TRIGGERED BY FLUCTUATION OF RESERVOIR WATER LEVEL

作　　者：李松林[1] 许强[1] 汤明高[1] 钱灵杰[1] 任俊谦 

机构地区：[1]地质灾害防治与地质环境保护国家重点实验室(成都理工大学),成都610059

出　　处：《工程地质学报》2017年第3期841-852,共12页Journal of Engineering Geology

基　　金：国家杰出青年科学基金(41225011);地质灾害防治与地质环境保护国家重点实验室开放基金项目(SKLGP2015Z008)资助

摘　　要：收集了三峡库区自2003年6月蓄水至2015年6月发生过显著变形或失稳的463处涉水老滑坡相关资料。以典型老滑坡为例分析了其不同形成模式及滑面形态,提出三峡库区老滑坡存在4类典型滑面形态,分别为弧形、靠椅形、折线形和直线形。通过统计分析不同滑面形态老滑坡对库水位升降的变形响应时间规律及涉水程度规律,可得以下结论:(1)弧形与直线形滑面滑坡以中部与前部涉水时产生变形为主,这两类滑坡受动水压力效应影响较大,主要在库水位下降阶段发生变形,尤其是首次蓄水至历史最高水位后的下降期;(2)由于对库水位下降的响应滞后性,部分直线形滑面滑坡在库水位下降后低水位运行期发生变形;(3)靠椅形滑面滑坡主要为前部涉水时产生变形,折线形滑面滑坡中后部涉水比例较其他3类滑坡高,这两类滑坡受库水浮托减重效应影响较大,变形集中在首次135m和175m蓄水的水位上升阶段。研究成果对三峡库区涉水老滑坡防治具有一定参考和借鉴意义。Much of relevant materials of 463 old landslides which had significant deformation in Three Gorges Reservoir Area are collected from June 2003 to June 2015. This paper studies the evolution models and slip-surface shapes of some typical old landslides. It concludes that there are 4 typical slip-surface shapes of circular,polyline,rectilinear and chair shape. Results of macroscopic analysis of wading extent and deformation time distribution can be summarized as follows.（ 1） The hydrodynamic pressure has obvious effect on the stability of the circular and rectilinear slip-surface landslides. Most of these two types of landslides deform at the lowering stage of water level when the front or middle is waded,especially after the first time to the highest water level.（ 2） A small part of the rectilinear slip-surface landslides is deformed at the stage of low water level after the drop because of lags in response.（ 3） The deformation occurs in the chair-shaped and polygonal line slip-surface landslides at the increasing stage of water level owing to effect of buoyancy weight loss,especially to the first 135 m and 175 m storage. Most ofthe chair-shaped slip-surface landslides are deformed when the front is waded as well as the rear wading extent of the polygonal line slip-surface landslides is higher than other 3 types. At last,the research results have a certain reference meaning for wading old landslides prevention in Three Gorges Reservoir Area.

关 键 词：三峡库区 老滑坡 滑动面形态 库水位变化 响应规律 

分 类 号：P642.2[天文地球—工程地质学]