安康罗家梁膨胀土滑坡特征与成因分析

目的分析膨胀土滑坡特征及成因,探讨膨胀土滑坡的滑动模式及滑坡发生的机理。方法根据野外调研和滑坡土体的岩性、物质成分、膨胀性、物理力学性质的测试进行分析研究。结果罗家梁滑坡是大型古滑坡体上新近发育的局部浅层滑动,滑坡体以黄褐、棕黄、黄绿色黏土为主,灰白、灰绿色黏土充填裂隙,或以薄膜附于裂隙表面;黏土矿物成分以伊蒙混合层为主,并含有蒙脱石;降水入渗、生活污水入渗及地下水的作用,导致滑带力学强度降低,加之边坡形态的改变,形成了明显的滑动—变形区域及多级解体裂缝,具有牵引式滑动、累进式破坏及蠕滑等特征。结论斜坡土体中强膨胀土夹层构成滑动面,当有水渗入及人工开挖边坡打破平衡时导致土体滑动。

Landslip characteristic and its genesis of expansive soil in Luojialiang,Ankang Area

Aim To analyze landslip characteristic and its genesis of expansive soil,discuss the slip model and forming mechanism.Methods The analysis is based on the field work and the measure of rock quality,composition,expansibility,physical mechanic property of expensive soil.Results The landslip in Luojialiang resulted from a partial shallow slip developing recently from a large-scale palo-slip body,which is mainly composed of fulvous,brown,olivine clay,the fissure is filled or adsorbed with gray,mignonette clay.The clay mineral mainly consists of illite-montmorillonite mixed layer with montmorillonite.With the precipitation,living water permeation and groundwater effect,the mechanic strength of slipband decreased and the shape of slope changing lead to the remarkable slip-deformation zone characteristic of multiply-fissure,retrogressive,progressive,creep-slide.Conclusion On condition of the violation of balance caused by the water permeation and artificial slop,the slipping plane occurred in the interbed of strong expensive soil in the inclination body.