高密度电法在不稳定斜坡勘察治理中的应用

Application of high density apparent resistivity method in surveying and harnessing of unstable slope

为查明湖南杨村一带因碎石、土体常年废弃堆积形成的不稳定斜坡的规模大小,采用高密度电法对其厚度和滑动界面进行了探测。根据土体和下伏基岩电阻率差异特征,对测量成果进行了推断解释;同时,以60Ω·m为异常上限,圈化了内部滑动界面。通过钻探验证,在20/L2测点揭露土体厚度为27.2m,物探推断厚度为24.0m,准确度达88.2%;在32/L3测点处揭露0~4.5m为含水土体和强风化碎石,与物探成果显示的浅表层状低阻十分吻合。由此说明,在探测目标层与基岩电性差异明显的情况下,通过高密度电阻率法测量可有效查明控滑控崩界面,可为地质灾害危险性评估和后期治理提供参考依据。

In order to obtain the information about the slope scale,the high density apparent resistivity method is used to ascertain the thickness and slipping interface of the unstable slope created by the soil and rocks abandon for many years in Yangcun Village in Hunan Province.Together with slipping interface sketching by the lower limit of 60Ω·m,the geophysical interpretations are carried out through the analysis on the electrical properties of soil mass and rocks.After the drilling,it is found that the actual thickness of the soil mass near the station 20/L2 is 27.2 m,comparing to the thickness 24.0 m from the geophycial testing conclusion with the accuracy of 88.2%.Soil and crashed rocks are explored at the depth from 0 to 4.5 m below the station 32/L3,which is matched very well with the shallow low-resistivity anomaly by geophycial method.All of above indicates the effectiveness of surveying unstable slope by the imaging method with high density resistivity on condition of overwhelming differences of electrical characters of target layer and bedrocks,which could provide the reference for the danger assessing and the further harnessing on geological disasters.