甘肃舟曲县牙豁口滑坡发育特征与成因分析  

The development characteristics and causes of the Yahuokou landslide in Zhouqu County,Gansu Province

作　　者：吴玮江[1] 王国亚[1] 刘兴荣[1] 马伊民 董耀刚[1] WU Weijiang;WANG Guoya;LIU Xingrong;MA Yimin;DONG Yaogang(Geological Hazards Prevention Institute,Gansu Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]甘肃省科学院地质自然灾害防治研究所,甘肃兰州730000

出　　处：《冰川冻土》2021年第2期544-554,共11页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(41362014);甘肃省科学院地质灾害防治与矿山地质环境修复创新团队(CX201801)资助。

摘　　要：2019年7月16日,位于舟曲—化马深大活动断裂带的舟曲县牙豁口发生滑坡,滑坡长1 920m,宽50~190m,体积212×10^(4)m^(3),为典型的推移式大型长条状断层破碎带堆积层滑坡。滑坡自上而下沿原老滑道分级分块逐步发育形成,滑动历时近50天,最大滑距500m,滑坡破坏X414县道、养鸡场等,并使岷江呈半堵塞状态,影响汛期行洪安全。通过现场调查、监测、无人机测量、岩土试验和收集历史滑坡资料,对牙豁口滑坡形成的地质环境、滑坡发育历史、滑坡分级分块特征、滑动过程和成因进行了系统研究。牙豁口滑坡分为上、下相对独立的两级滑坡。上级滑坡又可分为南支滑块和北支滑块两部分,在老滑坡的基础上长期孕育发展,上级滑坡北支滑块在2013年前就已活动,2019年7月16日上级滑坡南支滑块开始剧烈滑动,并推挤北支滑块前部一同复活滑动。上级滑坡约10×10^(4)m^(3)滑体下滑加载于下级滑坡,下级滑坡于7月24日由上向下逐步扩展变形和滑动,下级滑坡又可分为上、中、下三段滑体,滑坡前缘于8月10日达到岷江边,使岷江呈半堵状态。牙豁口滑坡总体具有孕育历史悠久、滑动历时长、滑动速度较低、分级分块差异性滑动的特点。长期活动的深大断裂带及凹槽状地形、软弱易滑的灰黑色风化破碎炭质板岩、地下水和大气降水的强烈作用、两侧崩滑体的堆积加载是滑坡发生的主要原因。Yahuokou landslide occurred in Zhouqu County on July 16,2019,which is located in Zhouqu-Huama active fault zone. The landslide is1 920 m long,50~190 m wide and 212×10^(4)m^(3) in volume. It is a typical large-scale accumulation layer landslide in the long fault fracture zone. The landslide developed gradually from top to bottom along the original old sideway. The landslide developed gradually from top to bottom along the old slide. The sliding lasted about 50 days,with the maximum sliding distance of 500 m. The landslide damaged X414 County Road and chicken farm,and made Minjiang River semi blocked,affecting flood safety in flood season. The geological environment,development history,classification and block characteristics,sliding process and causes of Yahuokou landslide are systematically studied through field monitoring,UAV(unmanned aerial vehicle)measurement,geotechnical test and the historical data of the landslide. Yahuokou landslide can be divided into two grades:upper and lower,which are relatively independent. The upper landslide can be divided into two parts:The South Branch and the North Branch. On the basis of the old landslide,the North Branch of the upper landslide has been active before 2013. On July 16,2019,the South Branch of the upper landslide began to slide violently and pushed the front of the North Branch of the landslide together to revive the slide.About 10×10^(4)m^(3) sliding mass of the upper landslide was loaded on the lower landslide,and the lower landslide gradually expanded from the top to the bottom on July 24. The lower landslide can be divided into three sections:The upper,middle and lower. The front edge of the landslide reached the edge of Minjiang River on August 10,making Minjiang River semi-blocked. Yahuokou landslide has the characteristics of long history,long sliding time,low sliding speed and differential sliding in different grades and blocks. The main causes of landslides are the long-term active deep fault zone and fluted terrain,the weak and slippery gray black weat

关 键 词：堆积层滑坡 断裂带 炭质板岩 分级分块 滑动过程 

分 类 号：P642.22[天文地球—工程地质学]