贵州核桃坪滑坡机理分析与稳定性评价研究

Analysis and Stability Evaluation of the Hetaoping Landslide in Guizhou

核桃坪滑坡位于贵州省印江土家族苗族自治县杉树乡南面群联村,2008年6月发生初次滑动后,于2014年汛期持续性强降雨后滑坡变形突然加剧,严重威胁到核桃坪组居民的生命和财产安全。因此,有必要对滑坡机理和稳定性进行研究,为后续滑坡防治提供依据。采用现场调查与勘察、地质分析与数值模拟等综合研究方法对滑坡变形破坏的地质力学机理和稳定性进行了研究。结果表明:核桃坪滑坡区上陡下缓的地形条件和覆盖层厚、强度低是滑坡形成的地形物质条件,而降雨持续时间长且降雨量大是滑坡形成的重要诱发因素,更是滑坡变形发展的主要控制因素;核桃坪滑坡的失稳力学模式为推移式滑坡,目前处于基本稳定-欠稳定的蠕动变形阶段;核桃坪滑坡在天然工况条件下稳定性尚好,但在持续暴雨工况条件下滑坡稳定性处于欠稳定状态。

The Hetaoping landslide is located in Qunlian Village,south of Shanshu Town,Yinjiang Tujiazu Autonomous County of Guizhou Province.After the first sliding in June 2008,the deformation of the landslide suddenly increased followed by the continuous heavy rainfall in 2014 flood season,seriously threatening the lives and property safety of the residents of Hetaoping Group.Therefore,it is necessary to study the mechanism and stability of the landslide,providing a basis for the subsequent landslide prevention and control.The geo-mechanical mechanism and the stability of the landslide deformation and failure are studied by applying comprehensive research methods such as the field investigation,the geological analysis and the numerical simulation.The results show that the terrain conditions of the Hetaoping landslide area,such as steep slope above and gentle slopes below,as well as the thickness and strength of the covering layer,are the material conditions for the formation of the landslide.The extensive and long rainfall duration are important triggering factors for the formation of the landslide,and are also the main controlling factors for the development of the landslide deformation.The instability mechanical model of the Hetaoping landslide is push-type landslide,which is currently in the stage of basically stable-unstable creep deformation.The stability of the Hetaoping landslide is satisfactory under natural conditions,but the stability of the landslide is in an unstable state under continuous rainstorm conditions.