天水市北山滑坡群发育特征及坡体结构分区  

Characteristics and slope structure of the Beishan landslide group in Tianshui City

作　　者：王浩杰 孙萍[1,4,5] 张帅 王涛[1,4,5] 任健 WANG Haojie;SUN Ping;ZHANG Shuai;WANG Tao;REN Jian(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Key Laboratory of Geohazard Prevention of Hilly Mountains,Ministry of Natural Resources,Fuzhou 350002,Fujian,China;Fujian Key Laboratory of Geohazard Prevention,Fuzhou 350002,Fujian,China;Observation and Research Station of Geological Disaster in Baoji,Shaanxi Province,Ministry of Natural Resources,Baoji 721001,Shaanxi,China;Key Laboratory of Active Tectonics and Geological Safety,Ministry of Natural Resources,Beijing 100081,China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]自然资源部丘陵山地地质灾害防治重点实验室,福建福州350002 [3]福建省地质灾害重点实验室,福建福州350002 [4]自然资源部陕西宝鸡地质灾害野外科学观测研究站,陕西宝鸡721001 [5]自然资源部活动构造与地质安全重点实验室,北京100081

出　　处：《地质力学学报》2023年第2期236-252,共17页Journal of Geomechanics

基　　金：国家自然科学基金项目(42130720,42293352);自然资源部科技人才工程资助项目(121106000000180039-2207)。

摘　　要：天水市北山地处秦岭北缘山地与黄土高原过渡地带,受强烈的内外动力耦合作用影响,诱发了呈带状分布的大型滑坡群,严重制约现阶段天水市区规划建设和灾害风险防控。此次研究在系统总结已有地质灾害资料的基础上,利用空-天-地一体化综合勘察手段,查明了天水市北山自西向东黄土厚度渐变特征、典型的斜坡结构类型及关键控滑地层,系统分析了地震滑坡的发育特征、分布规律和几何学、运动学特征。结果表明:天水市北山滑坡群沿藉河河谷北岸集中呈带状分布,滑坡类型主要为泥岩滑坡和黄土-泥岩接触面滑坡,多具有深层多级旋转-平移、多期次滑动的特征;地层结构为上覆第四系黄土和下伏新近系尧店组和甘泉组河湖相泥岩、黏土岩,坡体结构类型为顺层岩土质斜坡;天水市北山的坡体结构自西向东可分为3个典型区段,黄土厚度自西向东逐渐增大,海拔高程和表观摩擦角东西部低、中部高,滑坡后壁高度东西部高、中部低;天水市北山地震滑坡具有低角度启动和远程运动的特征,其等效摩擦系数(f)在0.21~0.28之间,且东、西区段地震滑坡的运动性更强。The Beishan area in Tianshui City is located in the transition zone between the mountainous area on the northern edge of the Qinling Mountains and the Loess Plateau.The solid internal and external dynamic coupling has induced large landslide groups with a zonal distribution,which seriously restricts urban planning and disaster risk prevention in Tianshui City.Based on the systematic summary of existing geological hazard data,this study used the space-sky-earth integrated survey method to identify the variations of loess thickness from west to east,typical slope structure types,and key slip-controlling strata.The seismic landslides’development characteristics,distribution rules,and geometric and kinematic features are systematically analyzed.The results show that the landslide groups in the Beishan area are concentrated along the north bank of the Jihe Valley in a zonal distribution.The landslide types are mainly mudstone landslide and loess-mudstone interface landslide,with multi-stage rotation,translation,and multi-stage sliding.The stratigraphic structure consists of the overlying Quaternary loess and the underlying lacustrine-fluvial mudstone and claystone of the Neoproterozoic Yaodian and Ganquan formations.The landslides belonging to the bedding rock slope have three typical slope structures from west to east.The loess thickness increases gradually from west to east,the elevation and apparent friction angle are lower in the east and west and higher in the middle,and the scarp height of the landslides is higher in the east and west and lower in the middle.In addition,the seismic landslides in this region have long-runout characteristics.The equivalent friction coefficients of these landslides are between 0.21 and 0.28,and the seismic landslides in the eastern and western sections have stronger movement.

关 键 词：天水市 黄土-泥岩滑坡 斜坡结构 地震滑坡 运动学特征 地质灾害 

分 类 号：P642.22[天文地球—工程地质学]