高密度电阻率法探测不稳定斜坡

Introduction about the method by using high density resistivity to detect unstable slopes

汶川大地震,山体开裂,出现多处大型滑坡,产生了大量不稳定斜坡。这类不稳定结构随时可能引发新的灾难。本文以实验室模型数据和某地震后不稳定斜坡为例,分析了不稳定斜坡区二维高密度电阻率法反演的电断面异常特征。结果表明,沉积岩地区的不稳定斜坡体与滑床间存在明显的电性差异,根据地形改正后的不稳定斜坡区视电阻率异常剖面,更直观地显示了不稳定斜坡体的纵横向展布、主滑动面位置与埋深,圈定了不稳定斜坡体的规模,较准确地确定了高阻垂直电性异常体(裂缝、空洞、溶洞)的形状、埋深等,从而为不稳定斜坡的治理提供了可靠的地球物理依据。

Some serious landslides and crack in mountain can be find in Wenchuan Earthquake. This kind of unstable slopes can engender new disaster at any moment. In this paper, taking the laboratory model data and a unstable slope after earthquake as an example,the authors studied anomaly characteristics of the 2-D high density resistivity ratio inversion section chromatogram of unstable slope and obtain terrain correction for apparent resistivity section. The results show that, for unstable slope in sedimentary areas, there exist obvious electric difference between unstable slope and slide bed. The apparent resistivity profile chromatogram of unstable slope area show clearly and intuitively the vertical and lateral distribution of unstable slope and the position and depth of main sliding plane. Therefore,the size of unstable slope mass can be delineated. It ensures shape and burial depth of high resistance vertical resistivity anomaly （for example fissure, cavity and karsts cave）. All of these are the reliable geophysical basis for unstable slope control.