关键词: 电成像技术, 城市浅层隐伏断裂, 电性结构间断面, 典型形式, 推断方法

Abstract: After the test detection of shallow buried fault in urban areas in the past a few years,progress has been made in resistivity tomography.According to the test results obtained from Olympic Park,Beijing,Shandong Province,Gansu Province and Shanxi Province,we have generalized the method and process for inferring the discontinuity of electrical structure(DES)reflecting a buried fault in urban areas from resistivity tomograms and its typical electrical features.In general,the layered feature of electrical structure is analyzed first of all for defining preliminarily whether a DES exists in the target area or not.Then the contours of resistivity in resistivity tomogram are analyzed from the deep to the shallow part.If they extend upwardly from the deeper part to shallower one and shape into the integral dislocation,great flexure(convergence)or gradient zone,it would indicate there exists the DES reflecting a buried fault.At last,horizontal tracking needs to be carried out for defining the trend of the DES reflecting a buried fault.DES can be divided into three types-type AB,ABA and AC.In the present paper,the Zhangdian-Renhe Fault system in Zibo City is taken as an example for illustrating how to use the method to infer the location and spatial distribution of a target fault.Geologic drill holes are placed based on our research results,and the drilling logs testify that our results are correct.However,the method of this paper is not exclusive and inflexible.It is expected to provide reference and help for inferring the shallow buried fault in urban areas from resistivity tomograms in the future.

Key words: resistivity tomography, shallow buried fault in urban area, discontinuity of electrical structure, typical feature, inferring method