工程地质学报2016，Vol.24Issue(1)：44-55,12.DOI:10.13544/j.cnki.jeg.2016.01.006
三峡库区藕塘滑坡变形失稳机制研究
DEFORMATION AND FAILURE MECHANISM OF OUTANG LANDSLIDE IN THREE GORGES RESERVOIR AREA
摘要
Abstract
The Outang landslide is a giant ancient consequent bedding rockslide of about 9.0×107 m3 in volume and 1.78km2 in area.It is a huge threat to the safety of lives and property of more than 3900 people.It involves the entire town relocation,which can be one of the serious landslide disasters in this area.On the basis of field investigation and engineering-geological exploration,the special geologic environment and characters of Outang landslide are examined in detail.The deformation characteristics of the landslide are studied in-depth with field monitoring data.On this basis the deformation and failure mechanism of Outang landslide are analyzed from the two following aspects.They are the geologic origin and the environment origin.The deformation trend of the landslide is also predicted using the stability calculation result.The result shows that:(1)The Outang landslide is a multi-phase consequent bedding rockslide with three landslide phases.It has the characteristics of apparent dip slide in 3D spatial form.(2)The particular geological factors include the landform,stratum lithology,geological structure and are the internal factors of landslide formation.(3 )The cyclical fluctuation of the reservoir water and the concentrated rainfall are the external environment factors inducing the landslide deformation.Analysis shows that the landslide deformation is significantly related to the water level reduction and the concentrated rainfall.Because the reducing speed of reservoir water level is much faster than that of the underground water,it forms seepage force in the landslide body apparently,and promotes the landslide deformation.The concentrated rainfall increases the self-weight and reduces the strength of slope mass,which makes a lot of water enrichment in easy sliding soft layer, softens sliding zone and hastens the landslide creep deformation.(4)The third phase landslide mass and the western side strong deformation zone have the possibility of unstable statement under extreme conditions.So it is inferred that the major failure mode of the landslide is a local buckling failure.In view of this,it is suggested to strengthen monitoring and to take corresponding engineering measures.关键词
三峡库区/藕塘滑坡/变形特征/失稳机制/稳定性预测Key words
Three Gorges Reservoir/Outang landslide/Deformation characteristics/Failure mechanism/Stability prediction分类
天文与地球科学引用本文复制引用
代贞伟,殷跃平,魏云杰,吕韬,罗建华,姚望..三峡库区藕塘滑坡变形失稳机制研究[J].工程地质学报,2016,24(1):44-55,12.基金项目
"十二五"国家科技支撑项目(2012BAK10B01),国家自然科学基金项目(41172254),中国地质调查局基金项目(1212011220124)资助. （2012BAK10B01）
