汶川地震前后都江堰山区滑坡滑动距离影响因素变化分析  

ANALYSIS ON THE CHANGE OF INFLUENCE FACTORS ON SLIPPING DISPLACEMENT OF LANDSLIDES IN DUJIANGYAN AREA BEFORE AND AFTER THE WENCHUAN EARTHQUAKE

作　　者：孟华君[1,2,3] 姜元俊[3] 张树轩[1] 张向营 李焕彬[1] 赵伟康 MENG Huajun;JIANG Yuanjun;ZHANG Shuxuan;ZHANG Xiangying;LI Huanbin;ZHAO Weikang(Key Laboratory of Neotectonic Movement and Geohazard, Ministry of Land and Resources, Beijing 100081, China;Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China;Institute of Mountain Hazards and Environment, CAS, Chengdu 610041, Sichuan, China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]国土资源部新构造运动与地质灾害重点实验室,北京100081 [3]中国科学院水利部成都山地灾害与环境研究所,四川成都610041

出　　处：《地质力学学报》2017年第6期904-913,共10页Journal of Geomechanics

基　　金：国家自然科学基金(41502339;41602367);中国地质科学院基本科研业务费专项经费(YYWF201523);中国地质调查局项目(DD20160267;DD20160271)

摘　　要：滑坡滑动距离作为滑坡防灾减灾的主要评价指标之一,不仅受滑坡体积和落差的影响,还与滑坡运动的地质环境作用相关。本文在对都江堰地区51个地震滑坡、16个降雨滑坡详细调查编目的基础上,采用数理统计方法分析了斜坡原始坡度、滑坡前后缘高差、滑坡平面形态、体积、滑体平均厚度及坡面摩擦系数等6个因素与滑坡水平滑动距离的相关性,借此厘清了汶川Ms8.0级大地震前后不同因素对不同类型滑坡运动的贡献大小,进而构建了不同成因类型滑坡的滑动距离预测关系式,可为龙门山区的滑坡防灾减灾工作提供参考。研究表明:影响都江堰地区地震滑坡运动距离的主要因素有滑坡体积(lg V)、斜坡原始坡度(α)、滑坡平面形态(R)和滑坡前后缘高差(ΔH);而控制降雨滑坡运动距离的主要因素为滑坡前后缘高差(ΔH)、滑坡体积(lg V)、斜坡坡度(α)和斜坡表面摩擦系数(μ);汶川地震后,影响该地区降雨滑坡滑动能力的因素发生了变异,各因素与滑坡滑动距离的相关性较弱,显示出其贡献率在急剧减弱,仅滑坡体积(lg V)与滑动距离的相关性较强。Slipping displacement of landslide is one of the most important assessment indexes for prevention and mitigation of landslide disaster,which is not only controlled by landslide volume and drop but also related to the influence of topographical environment.On the basis of detailed field investigation and inventory for51seismic-induced landslides and16rainfall-induced landslides seated in Dujiangyan area,the correlation between six factors and horizontal slipping displacement of landslides are analyzed through mathematical statistic method,factors including depositional gradient of slope,ridge height difference before and after the earthquake,plane shape,volume,and average thickness of landslide mass and friction coefficient of slope surface.Afterwards,the influence of different factors on different types of landslides before and after Wenchuan earthquake are sort out,and the predictive formulas of slipping displacement due to different causes are built which may support the disaster mitigation in the future.The preliminary conclusions reveal that slipping displacements of seismic-induced landslides are mainly affected by landslide volume(lg V),depositional gradient of slope(α),plane shape(R)and ridge height difference before and after the earthquake(ΔH);while rainfall-induced landslides are mainly affected by ridge height difference before and after the earthquake(ΔH),landslide volume(lg V),depositional gradient of slope(α)and friction coefficient of slope surface(μ).After the Wenchuan earthquake,the factors affecting the sliding of rainfall-induced landslides are changing with a relatively low correlation with slipping displacement,showing that their influence are decreasing and only landslide volume(lg V)still stays a strong correlation.

关 键 词：都江堰白沙河 汶川地震 地震滑坡 降雨滑坡 滑动距离 

分 类 号：P642.22[天文地球—工程地质学]