动水作用下靠椅状土质滑坡变形机理及阈值初探——以三峡库区八字门滑坡为例  

Deformation mechanism and threshold preliminary exploration of chair-shaped soil landslide:case of Bazimen Landslide in Three Gorges Reservoir area

作　　者：李卓骏 邓茂林[1,2,3] 周剑 张富灵 林琰 LI Zhuojun;DENG Maolin;ZHOU Jian;ZHANG Fuling;LIN Yan(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education,China Three Gorges University,Yichang 443002,China;Hubei Key Laboratory of Disaster Prevention and Mitigation,China Three Gorges University,Yichang 443002,China;National Field Observation and Research Station of Landslides in Three Gorges Reservoir Area of Yangtze River,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学三峡库区地质灾害教育部重点实验室,湖北宜昌443002 [2]三峡大学防灾减灾湖北省重点实验室,湖北宜昌443002 [3]三峡大学湖北长江三峡滑坡国家野外科学观测研究站,湖北宜昌443002

出　　处：《人民长江》2020年第7期124-129,140,共7页Yangtze River

基　　金：国家青年科学基金项目“考虑不同前期时效荷载影响的裂隙硬岩流变特性研究”(41602301);三峡库区地质灾害教育部重点实验室基金项目“库水位作用下靠椅状滑坡变形规律与预警研究”(2017KDZ07);三峡大学学位论文培优基金项目“库水作用下靠椅状土质滑坡变形规律与预警研究”(2019SSPY028)。

摘　　要：靠椅状土质滑坡的演化时间久远,滑坡本身较为稳定,但在水库蓄水影响下,这类滑坡的监测变形曲线每年都出现了位移"阶跃",严重影响了滑坡的预警预报。以三峡库区典型靠椅状土质滑坡——八字门滑坡为例,结合多年的现场调查、15 a的监测数据,对靠椅状土质滑坡的变形机理进行了分析总结,并从阈值的角度对滑坡的响应规律开展了定量化分析。结果表明:①这类滑坡的变形特点直接影响了滑坡的统计分析。②通过对全自动监测数据的定量化分析,得到了这类滑坡受库水位下降速率影响而启动的阈值为:阶段Ⅰ,0.2 m/d并持续20 d左右;阶段Ⅱ,0.4 m/d并持续30 d左右。The evolution history of chair-shaped soil landslide is long and the landslide itself is relatively stable.However,under the influence of periodic rise and fall of water level in the Three Gorges Reservoir,the monitoring deformation curve of this kind landslide shows stepped displacement every year,which seriously affects the early warning and forecast of the landslide.Taking the Bazimen Landslide as an example,combining multi-year field investigation and 15-year monitoring data,the deformation mechanism of the landslide was analyzed and summarized,and the landslide response law was quantitatively analyzed from the perspective of threshold value.The results showed that:①the statistics of landslide threshold was directly affected by deformation characteristics of this kind landslide.②through the quantitative analysis on automatic monitoring data,the landslide failure threshold value affected by the reservoir water level declining rate was obtained:stage i,0.2 m/d and lasting about 20 days;stage ii,0.4 m/d and lasting about 30 days.

关 键 词：靠椅状滑坡 位移阶跃 变形特征 滑坡阈值 八字门滑坡 三峡库区 

分 类 号：P642[天文地球—工程地质学]