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。
The large scale clayey soil landslides are frequently occurred in the middle and lower reaches of Wei River. The his- torical Bojishan Landslide is located at the north slope of urban Baoji City. As one of the high risk landslides monitored by Bu- reaus of Land Resources of both Baoji City and Shanxi Province, this ancient landslide has been observed having a long term theological 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 evalua- ted. The comprehensive sliding zone investigation consisted of characterizing of the soil surface soil, rock and groundwater con- ditions 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 stra- tum 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 char- acteristics. Under the action of the groundwater, the soil stratum is fissured and a continuous shearing zone could be formed and therefore triggering the sliding.
作者
董晓娟
辛鹏
DONG Xiaojuan XIN Peng(Beijing Guodaotong Highway Design and Research Institute Co. , Ltd. , Beijing 10053 Key Laboratory of Neotectonic Movement and Geohazard, Ministry of Land and Resources,Institute of Geomechanics, Chinese Academy of Geological Science, Beijing 100081)
出处
《土工基础》
2017年第2期166-171,共6页
Soil Engineering and Foundation
关键词
粘土质滑坡
形成机制
粘土矿物
蠕变
Clayey Soil Landslides
Triggering Mechanism
Clay Minerals
Rheological Deformation
