隐伏型软硬岩接触带温纳三极联合反演成像模拟及应用  

Simulation and Application of Wenner AMN&MNB Joint Inversion Imaging in Concealed Soft and Hard Rock Contact Zone

作　　者：谭磊[1,2,3,4] 江晓益 胡雄武 徐虎[3] TAN Lei;JIANG Xiaoyi;HU Xiongwu;XU Hu(School of Earth and Environment,Anhui University of Science and Technology,Huainan 232001,Anhui,China;Zhejiang Institute of Hydraulics&Estuary(Zhejiang Institute of Marine Planning and Design),Hangzhou 310020,Zhejiang,China;Zhejiang Guangchuan Engineering Consulting Co.,Ltd.,Hangzhou 310020,Zhejiang,China;Key Laboratory of Hydraulic Disaster Prevention and Mitigation of Zhejiang Province,Hangzhou 310020,Zhejiang,China)

机构地区：[1]安徽理工大学地球与环境学院,安徽淮南232001 [2]浙江省水利河口研究院(浙江省海洋规划设计研究院),浙江杭州310020 [3]浙江广川工程咨询有限公司,浙江杭州310020 [4]浙江省水利防灾减灾重点实验室,浙江杭州310020

出　　处：《隧道建设（中英文）》2023年第9期1501-1510,共10页Tunnel Construction

基　　金：浙江省水利防灾减灾重点实验室开放项目(FZJZSYS21001);安徽省高校优秀青年骨干人才项目(gxgwfx2022011);浙江省水利河口研究院院长科学基金(ZIHE21Y006)。

摘　　要：为研究温纳三极(AMN&MNB)联合反演成像在岩层接触带划分中的有效性,构建整体、局部表层高阻体的软硬岩层地电模型,分析不同高密度电法装置对反演电阻率的响应特征,探讨温纳三极联合反演成像对覆盖层电阻率及厚度变化下岩层接触带的识别能力,并通过改变接触带倾角研究电阻率断面的响应特征。结果表明:1)地表局部高阻体对反演断面的干扰要强于整体高阻体,但影响深度较浅;2)不同装置的反演断面与预设模型基本吻合,但温纳三极联合反演探测深度较大,且对倾角的刻画更加精细;3)降低覆盖层电阻率或增加覆盖层厚度,温纳三极联合反演对倾角的识别能力随之下降;4)温纳三极联合反演能追踪岩层倾角的变化,但高阻上覆岩层易在接触带部位产生虚假低阻异常。结合泗安水库导流隧洞岩层划分的应用可知,温纳三极联合反演成像较常规电法装置获得的接触带产状及位置与实际揭露吻合度更高。To investigate the effectiveness of Wenner AMN&MNB joint inversion imaging in the division of rock contact zones,a geoelectric model of soft and hard rock with integral and local surface high-resistance bodies is constructed,and the response characteristics of different high-density electrical arrays to the inversion resistivity are analyzed.Furthermore,the ability of Wenner AMN&MNB joint inversion imaging to identify the contact zone of rock strata under varying overburden resistivity and thickness is discussed,and the response characteristics of the resistivity section are investigated by changing the dip angle of the contact zone.The results reveal the following:(1)The interference of the local high-resistance body on the inversion section is stronger than that of the whole high-resistance body,but the influence depth is shallow.(2)The inversion fracture surfaces of different arrays are consistent with the preset models,but the Wenner AMN&MNB joint inversion has a larger detection depth and a more detailed description of the dip angle.(3)With a decrease in overburden resistivity or an increase in overburden thickness,the identification ability of Wenner AMN&MNB joint inversion to dip angle decreases.(4)The Wenner AMN&MNB joint inversion can track the change of rock dip angle,but the high-resistance overlying strata are prone to false low-resistance anomalies in the contact zone.Based on the application of rock stratum division of diversion tunnel at Si′an reservoir,the occurrence and position of contact zone obtained by Wenner AMN&MNB joint inversion imaging are more consistent with the actual exposure than those obtained by conventional electrical method device.

关 键 词：岩层接触面 软硬岩 高密度电法 温纳三极 电阻率联合反演成像 

分 类 号：U45[建筑科学—桥梁与隧道工程]