比较严重的地质滑坡_Daguangbao landslide Engineering geological mappin

  本文关键词：大光包滑坡工程地质研究，由笔耕文化传播整理发布。

大光包滑坡工程地质研究

ENGINEERING GEOLOGICAL STUDY ON DAGUANGBAO LANDSLIDE

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HUANG Runqiu,ZHANG Weifeng,PEI Xiangjun （State Key Laboratory of Geohazard Prevention and Geoenvironment Protection（ Chengdu University of Technology）, Chengdu 610059）

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

文章摘要：大光包滑坡是5·12汶川MS 8.0级特大地震触发的规模最大的滑坡。滑坡位于汶川地震发震断裂上盘，距发震断裂直线距离3.0～4.5km，覆盖面积7.12km2，体积11.59×108m3，是我国有史料记载以来规模最大的滑坡，也是目前世界上已知为数不多的几个10×109m3以上的超大规模滑坡之一。本文作者自2011以来，在过去工作基础上，对该滑坡开展了1！2000滑坡工程地质测绘，结合物探、坑槽探及浅孔钻探等工作，编制了滑坡工程地质系列图件，从而进一步查明了大光包滑坡的平面和空间形态、滑体结构、滑面位置和堆积特征等，获得了较为完整的滑坡要素定量数据。研究成果还原了大光包滑坡发生时的真实场景；揭示了滑坡堆积地貌特征、植被分布、岩性分布以及堆积体结构特征等，认为大光包滑坡是受强震和特定地形条件、岩体结构条件（层间剪切断层和两组陡裂结构面）控制的“楔形体”失稳。在此基础上，根据滑坡的要素组成和运动堆积特征，，对滑坡进行了分区，分为滑坡断壁区、主滑堆积区和次滑堆积区3个大区，进一步划分为10个小区，分析阐明了各区特征。最后，对大光包滑坡的发生过程和形成机理进行了概要分析，将其概括为5个主要阶段：即强震拉裂阶段、锁固段剪断及“楔形体”失稳阶段、高速滑动和“急刹车”运动堆积阶段、拆离滑动阶段、断壁崩滑阶段。研究还发现：强震作用下滑带的进一步碎裂化，以及可能出现的水击作用可能是滑坡骤然启动的主要原因。

Abstr：Daguangbao landslide with an area of 7.12km2 and a volume of 1.159 billion m3 is the largest landslide triggered by the Wenchuan MS8.0 Earthquake occurred on May 12th,2008,and also is the largest one in China and one of the few giant landslides more than one billion m3 in the world.It is located in the hanging wall of the seismogenic fault of the Wenchuan earthquake,and 3.0~4.5km away from it.The authors＇ team has conducted a engineering geological survey including mapping,geophysical exploration,pitting and boreholes with a scale of 1!2000 since 2011.According to the data,we finished a series of geological maps including a comprehensive plane map and 25 sections.The spatial shape of the landslide,pre- and post-failure structures,slip surface and its characteristics were further investigated and a set of quantitative data about Daguangbao landslide features was obtained.We found it was a huge“wedge”failure with a strike slipping sliding along a bedded shear fault. According to the description of witnesses and structures of the accumulation,we rebuilt the experience of the slope failure and sliding process during the strong quaking.Basically,it can be divided into five stages：shattering-tensile cracking,cutting through of the front locking section,“suddenly braking”and napping motion,detaching sliding on both sides of the accumulation and finally secondary sliding of the scarp cliff.The accumulation can be divided into three area and ten sub-areas.They are the main scarp area,the accumulation area,and the back depression area, which corresponding to three,four and three sub-areas respectively.

文章关键词：

Keyword：:Daguangbao landslide Engineering geological mapping Engineering geological zonation Formation mechanism Wedge failure

课题项目：地质灾害防治与地质环境保护国家重点实验室团队课题（SKLGP20122001）,国家自然科学基金重点项目（编号：41130745）资助.

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  本文关键词：大光包滑坡工程地质研究，由笔耕文化传播整理发布。