为研究切割作用下牵引式古滑坡复活机理,通过现场调研及地质勘测获得了国道S206 古滑坡的地层结构特征、变形特征等,得到了古滑坡存在的有力证据,并对滑坡区进行了稳定性分析.结果表明:地质背景、勘察结果表明该古滑坡属牵引式古滑坡;区域结构破碎的岩体、软弱夹层为古滑坡的形成提供了物质基础,前缘深切沟槽提供了空间条件;降雨促使了古滑坡的复活,前缘切割作用是古滑坡复活的直接诱因;不平衡推力法分析结果表明该滑坡在降雨情况下属不稳定状态,监测结果显示古滑坡复活后处于蠕滑状态,雨季时进入变形滑动阶段.可见地质背景是牵引式滑坡形成的内因,降雨、前缘切割是牵引式古滑坡复活的外因.
In order to study the resurrection mechanism of retrogressive ancient landslide under cutting action,geological investiga-tion and geological survey were used to investigate the stratigraphic structure characteristics and deformation characteristics of an ancient landslide in National Way S206.The evidence of the existence of ancient landslides was obtained by rock core.Stability analysis of landslide area was done by the investigation results.The analysis shows these as follows.Broken rock mass and weak interlayer in the regional structure provide the material basis for the formation of the retrogressive ancient landslide,and the front deep incision groove provide the space conditions.Rainfall promotes the formation of the ancient landslide revival,and the leading edge cutting is the trac-tion effect.The calculation results show that the landslide is in an unstable state under rainfall conditions.The monitoring results show that the ancient landslide is in a creeping state after its resurrection,and enters the deformation and sliding stage in the rainy season.It is concluded that the geological background is the internal cause of the formation of the retrogressive ancient landslide,and the rain-fall and the front edge cutting are the external causes of the resurrection.