贵州山区堆积层滑坡形成机制及防治措施

Formation Mechanism and Control Measures ofAccumulation Landslide in Guizhou Mountainous Area

为使山区堆积层滑坡的治理措施更加具有针对性和经济性,以贵州省息烽县黄草坝滑坡为例,通过详细勘查、数值模拟等方法,分析滑坡的变形特征和岩土体工程特性,提出有效的滑坡治理措施。结果表明:①黄草坝滑坡表层黏土的透水性为微—极微,土体长期处于饱和或近饱和状态,抗剪力学指标较低,在工程活动的扰动下发生局部失稳,进而牵引后部土体发生滑移;②由于堆积层厚度分布不均,性质差异较大,变形区未形成连续的滑移面;③滑坡以表层黏土蠕动变形为主,不会发生深层滑动。结合滑坡岩土组合特征,提出“地表截水+地下盲沟、碎石桩排水”的综合治理方案,监测结果表明治理效果良好,该治理方法可为类似滑坡治理工程提供借鉴。

In order to make the treatment measures of accumulation landslide in mountainous area more targeted and economical,taking Huangcaoba landslide in Xifeng County,Guizhou Province as an example,through detailed investigation and numerical simulation,the deformation characteristics and geotechnical engineering characteristics of the landslide are analyzed,and effective landslide treatment measures are proposed.The results show that:①The water permeability of the shallow clay in the landslide is slight to very slight,and the soil is saturated or nearly saturated for a long time,and the shear strength is very low,and the accumulation slide under the disturbance of engineering activities,and then cause the soil mass at the rear to slip;②Because of the uneven distribution of the thickness of the accumulation layer and the great difference in its properties,then it s no continuous slip plane is formed in the deformation zone;③The landslide is dominated by creep deformation of surface clay,and no deep sliding will occur.The comprehensive treatment programme of‘surface water interception+underground blind ditch and gravel pile drainage’is proposed by the characteristics of landslide rock soil combination,and the monitoring results show that the treatment effect is good on the landslide.The treatment method can provide reference for similar projects.