土工基础

›› 2017, Vol. 31 ›› Issue (2): 166-171.

• 工程实录 • 上一篇    下一篇

粘土岩质大型滑坡滑带形成机制研究

董晓娟1，辛 鹏2   

  1. （1.北京国道通公路设计研究院股份有限公司，北京 100053；
    2.中国地质科学院地质力学研究所 国土资源部新构造运动与地质灾害重点实验室, 北京 100081）
  • 收稿日期:2017-01-03 修回日期:2017-01-22 出版日期:2017-04-20 发布日期:2017-05-04
  • 作者简介:董晓娟（1983-），女，硕士，工程师，研究方向为与公路相关的连坡治理设计等。 通讯简介：辛〓鹏（1984-），男，博士，副研究员，研究方向为地质灾害。

The Triggering Mechanism of the Large Scale Landslide in Clayey Soils

DONG Xiaojuan1, XIN Peng2   

  1. (1.Beijing Guodaotong Highway Design and Research Institute Co., Ltd., Beijing 10053;
    2.Key Laboratory of Neotectonic Movement and Geohazard, Ministry of Land and Resources; Institute of Geomechanics, Chinese Academy of Geological Science, Beijing 100081)
  • Received:2017-01-03 Revised:2017-01-22 Online:2017-04-20 Published:2017-05-04

摘要： 粘土质大型滑坡在渭河中下游地区广泛分布，簸箕山大型老滑坡位于宝鸡市市中心北坡，其长期蠕变滑动致灾风险较高，是陕西省与宝鸡市国土局重点监测的大型滑坡。为判别分析滑坡变形监测数据与滑动趋势，急需理清其滑带变形样式和滑体运动过程。基于滑坡地形及地层岩性、地下水调查，结合连续取芯钻探数据，进行了滑带及原岩物质成分、水理化性质及应力应变特征的物理化学实验，通过滑带与原岩的实验数据对比分析，结论如下：（1）簸箕山滑坡滑带发育于三门组粘土岩黏粒含量较高的层位中，滑坡蠕变变形亦集中于该位置、渐进扩展；（2）滑带粘土矿物以蒙脱石为主，具有较强的膨胀性和裂隙化特征，使得粘土岩在地下水作用下发生劈理化、塑性化及泥质化，使得剪切面贯通形成滑带。

关键词: 粘土质滑坡, 形成机制, 粘土矿物, 蠕变

Abstract: The large scale clayey soil landslides are frequently occurred in the middle and lower reaches of Wei River. The historical Bojishan Landslide is located at the north slope of urban Baoji City.  As one of the high risk landslides monitored by Bureaus of Land Resources of both Baoji City and Shanxi Province, this ancient landslide has been observed having a long term rheological deformation and is justified to have high sliding probability. In order to accurately interpret the monitored data and predict the trend of the slope movement, the sliding zone, its dimension as well as the deformation pattern need to be evaluated. The comprehensive sliding zone investigation consisted of characterizing of the soil surface soil, rock and groundwater conditions through the test boring program. The mineral component, physical and mechanical properties of the sliding zone are also evaluated. The following results are concluded: 1) The sliding zone of Bojishan Landslide is within the high clay content stratum of Claystone of Sanmen Formation. The observed progressive rheological movements are also in this soil stratum. 2) The clay mineral component in the sliding zone consists predominantly of montmorillonite with strong fissuring and expansion characteristics. Under the action of the groundwater, the soil stratum is fissured and a continuous shearing zone could be formed and therefore triggering the sliding.

Key words: Clayey Soil Landslides, Triggering Mechanism, Clay Minerals, Rheological Deformation