Optimizing data for electrical resistivity tomography in hardened sites through the ratio method  

基于比值法的硬化场地电阻率层析成像法数据优化

作　　者：Jiang Fuyu Gao Likun Chen Haijun Ni Jiong Li Fuqiang 蒋甫玉;高丽坤;陈海军;倪炯;李富强(河海大学地球科学与工程学院,南京211100;江苏省地质矿产局第一地质大队,南京210041;南京水利科学研究院,南京210029;中国能源建设集团湖南省电力设计院有限公司,长沙410007)

机构地区：[1]School of Earth Sciences and Engineering,Hohai University,Nanjing 211100,China [2]The First Geological Brigade of Jiangsu Geology and Mineral Resources Bureau,Nanjing 210041,China [3]Nanjing Hydraulic Research Institute,Nanjing 210029,China [4]China Energy Engineering Group Hunan Electric Power Design Institute Co.,Ltd.,Changsha 410007,China

出　　处：《Journal of Southeast University(English Edition)》2024年第4期372-385,共14页东南大学学报（英文版）

基　　金：National Key Research and Development Program of China(No.2021YFC3000103).

摘　　要：To reduce the shielding effect of hardened layers on electrical resistivity tomography,a ratio method based on the distortion correction principle and the isolation coefficient is proposed.The effects of the resistivity and thickness of hardened concrete layers on the detection of target objects are explored.Both numerical simulations and indoor tank tests indicate that when the ratio method is employed to correct the original collected data,the maximum allowable error for the isolation coefficient should not exceed 1%.Notably,when the ratio of hardened layer thickness to electrode spacing does not exceed 1,correction through this method significantly enhances the recognition capability of target objects.However,when the hardened layer thickness is greater than the electrode spacing by a factor of 2 or more,the ratio method cannot achieve satisfactory results.The case study of flood control engineering detection in the Zhangxi section of the Huangpen River in Dongzhi County demonstrates that the detection effect after correction by the ratio method is comparable to that for the adjacent unhardened pavement,and the influence of the hardened layer is obviously weakened,resulting in more reliable results.为减弱硬化层的屏蔽效应对电阻率层析成像的影响,在探讨具有不同电阻率大小、不同厚度的混凝土硬化层对目标体探测影响的基础上,提出了一种考虑隔离系数的基于畸变校正原理的比值法.数值模拟试验和室内水槽试验结果表明,利用比值法对原始采集数据进行校正处理时,选择的最大隔离系数允许误差应当不大于1%.硬化层厚度与电极距的比值不大于1时,经比值法校正后,能明显地提升对目标体赋存状态的识别能力;但当硬化层厚度达到2倍电极间距及以上时,比值法亦不能达到较好的效果.东至县张溪河段黄湓河防洪治理工程探测实例表明,经比值法校正后的探测效果与邻近未硬化路面相当,明显削弱了硬化层的影响,得到了更为可靠的成果.

关 键 词：ratio method resistivity tomography hardened site distortion principle data optimization 

分 类 号：P631[天文地球—地质矿产勘探]