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

摘要： 经过几年的试验,探测城市浅层隐伏断裂的电成像技术已取得进展。根据在北京奥运村、山东、甘肃和山西等地的试验探测结果,总结了利用电成像结果推断反映城市浅层隐伏断裂的电性结构间断面的方法、步骤及其典型表现形式。一般情况下,在分析时,首先分析电性结构的层状特征,以此初步判定探测区域中是否存在电性结构间断面;其次,要由深入浅分析电阻率等值线,如果它们能够从探测剖面的深部向上延伸到浅部,且存在等值线的整体性错断、强烈(集中)弯曲或梯度带,则表明存在表征隐伏断裂的电性结构间断面;最后需进行水平追踪分析,以确定表征隐伏断裂的电性结构间断面的空间展布。通过总结,可将电性结构间断面分为AB、ABA和AC3种类型。在文中,以淄博段张店-仁河断裂系为例,详细说明了如何使用所总结的方法来推断目标隐伏断裂的位置及空间展布。根据研究结果布设了工程钻孔,其结果证实文中的推断是正确的。不过,文中介绍的方法不是惟一的、死板的,切不可生搬硬套,仅期望为今后利用电成像结果推测城市浅层隐伏断裂的工作提一些供参考和帮助。

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