高密度电法在黄土-泥岩接触面滑坡勘察中的应用

APPLICATION OF HIGH-DENSITY ELECTRICAL METHOD IN LOESS-MUDSTONE INTERFACE LANDSLIDE INVESTIGATION

受特殊的地质地貌和大地构造背景影响,历史上多次强震在宁夏西吉县诱发了大量的黄土-泥岩接触面滑坡,给当地人民生命财产安全带来严重威胁。因此,探明这类滑坡的地层结构、基岩面埋深及空间展布情况,对进一步开展黄土-泥岩接触面滑坡的形成机理和危险性评价研究具有重要意义。文章利用高密度电法对宁夏西吉县苏堡村滑坡进行探测,并结合钻孔资料进行了验证。勘察结果表明:电阻率参数能够很好的反应研究区的地层分布特征,表层疏松干燥的黄土为高阻反映,随着埋深增加,含水量较大的黄土呈现出低阻反映,在黄土与泥岩接触带饱水区呈现低阻反映。高密度电法在黄土-泥岩接触面滑坡勘察中具有较好的适应性,能为进一步分析滑坡机理和防治提供可靠的地球物理依据。

Due to special geological conditions and regional geotectonic settings, several strong earthquakes occurred in Xiji county, Ningxia province in history, which induced a large number of loess-mudstone interface landslides, and brought serious threat to the safety of local people’ s life and property. Therefore, it is of great significance to explore the formation mechanism and risk assessment of loess-mudstone interface landslides by studying the formation structure, depth of bedrock and spatial distribution of such landslides. By using the high-density method, the stratum structure in the slope area was detected, and the survey results were validated by the bore hole columnar section. The observations of the resistivity well reflected the stratigraphy distribution. The loose and dry loess in the surface has high electrical resistance, and drops down with water content increases. The contact zone of mudstone and loess is saturated, which has low electrical resistance. This research proves that high density electrical method has good adaptability in loess-mudstone interface landslide investigation, which can provide reliable geophysical basis for further analysis of landslide mechanism and prevention.