高密度电法对带破碎状溶壳溶洞探测数值模拟  

Detection Numerical Simulation of Karst Cave with Broken Shell by High Density Resistivity Method

作　　者：王志鹏 刘江平[1] 王鸣谦 易磊 Wang Zhipeng;Liu Jiangping;Wang Mingqian;Yi Lei(Institute of Geophysics and Geomatics,China University of Ceosciences,Wuhan Hubei 430074,China)

机构地区：[1]中国地质大学地球物理与空间信息学院,湖北武汉430074

出　　处：《工程地球物理学报》2019年第2期193-202,共10页Chinese Journal of Engineering Geophysics

基　　金：国家自然科学基金项目(编号:41574121)

摘　　要：高密度电法勘探中,不同条件下的溶洞其反演电阻率特征有差异,溶洞为空洞时反演电阻率表现为高阻,而当溶洞周围存在破碎状溶壳时,可能表现为低阻异常,所以对带破碎状溶壳溶洞的电阻率反演特征很难判断。为了研究这一类地质问题,通过构建不同溶壳厚度的溶洞模型进行正演模拟,利用最小二乘法对模型的地电断面进行反演,比较分析破碎状溶壳厚度对反演结果的影响。然后改变模型中的溶洞深度以及排列装置,分析溶洞深度和排列装置对结果的影响。结果表明:随着溶壳厚度的增加,溶洞的反演电阻率由高阻变为低阻;溶洞深度越小,反演电阻率越高,溶壳厚度对反演结果的影响越大;不同排列装置得到的正反演结果有很大的差异性。In high-density electrical prospecting,karst caves may show different inversion resistivity characteristics under different conditions. When the karst cave is empty, the inversion resistivity shows high resistance, when there is a broken shell around the karst cave, it may show a low resistance anomaly. Therefore, it is difficult to judge the resistivity inversion characteristics of karst caves with broken shell. In order to study this kind of geological problem, the forward modeling of karst cave with different shell thicknesses was carried out, and the geoelectric section of the model was inverted by using the least square method.Then, the karst cave depth and arrangement device in the model were changed, in order to analyze the influence of the karst cave depth and arrangement device on the results.The results show that the inversion resistivity changes from high resistance to low resistance with the increase of the shell thickness.The smaller the cave depth is, the higher the inversion resistivity is, and the greater the influence of the shell thickness to the inversion result is.The forward inversion results obtained by different arrangement devices are quite different.

关 键 词：岩溶溶洞 高密度电法 破碎状溶壳 数值模拟 

分 类 号：P631.3[天文地球—地质矿产勘探]