综合物探方法在复杂地质条件下公路隧道勘察中的应用  

Application of Comprehensive Geophysical Methods in Highway Tunnel Investigation under Complex Geological Conditions

作　　者：李凯 侯秋平 邹杰 弓晓晓 杨廷国 施志坤 普新凯 Li Kai;Hou Qiuping;Zou Jie;Gong Xiaoxiao;Yang Tingguo;Shi Zhikun;Pu Xinkai(YCIH No.1 Engineering Survey and Design Co.,Ltd,Kunming Yunnan 650031,China;Yunnan Green Intelligent Construction Research Institute Co.,Ltd.,Kunming Yunnan 650031,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu Sichuan 610059,China)

机构地区：[1]云南建投第一勘察设计有限公司,云南昆明650031 [2]云南绿色智能建造研究院有限公司,云南昆明650031 [3]成都理工大学油气藏地质及开发工程国家重点实验室,四川成都610059

出　　处：《工程地球物理学报》2024年第5期820-828,共9页Chinese Journal of Engineering Geophysics

基　　金：油气藏地质及开发工程国家重点实验室(成都理工大学)开发基金(编号:PLC20210109);云南建投第一勘察设计有限公司科技项目(编号:YKS2023RD04)。

摘　　要：西南部复杂山区的隧道建设对加快我国交通强国的建设具有重要意义,为了查明隧道的地质情况,以保证隧道施工的安全,必须提高公路隧道的勘察精度。为了提高勘察的反演精度,实现精细化解译,本次研究在XX隧道勘察过程中,采用EH4大地电磁测深法、钻孔地球物理测井方法、水压致裂法地应力测试、结合三维立体成图技术,建立了以电磁法为主导的复杂地质条件下公路隧道综合物探模式:①利用三维大地电磁测深法通过横纵断面对比反演结果,圈定异常区域的展布;②利用声波测井和钻孔成果验证异常解释的准确性;③采用水压致裂法地应力测试明确隧道的应力分布和岩爆等级;④利用三维立体成图技术。在标高3500 m以下,共圈定出5个异常区域,异常纵向长度30~60 m不等,最深处约625 m;其中隧道里程K31+620—K31+680处异常横向最大宽度约45 m、里程K33+585—K33+620异常横向宽度最大约85 m。采用综合物探方法准确识别出了隧道穿越区的构造、岩性、不良地质体以及异常的分布范围,从而为隧道的设计提供了依据,并为隧道的后续施工提出了建议,对同类项目具有一定的借鉴意义。The construction of tunnels in complex mountainous areas in the southwest China is of great significance to accelerate China’s construction of a strong transportation country.In order to find out the geological condition of the tunnel and ensure the safety of the tunnel construction,the high-precision survey of the tunnel becomes particularly important.In order to improve the inversion accuracy and achieve refined interpretation,in the process of XX tunnel investigation,EH4 magnetotelluric sounding method is integrated with borehole geophysical logging method,hydraulic fracturing method of in-situ stress testing and three-dimensional mapping technology,a comprehensive geophysical exploration model of highway tunnel under complex geological conditions is established.Firstly,three-dimensional magnetotelluric sounding method is used to delineate the distribution of the anomaly region by comparing the inversion results of transverse and longitudinal sections.Secondly,acoustic logging and drilling results are used to verify the accuracy of anomaly interpretation.Then,the stress distribution and rock burst grade of the tunnel are determined by ground stress test with hydraulic fracturing method.Finally,five abnormal regions are delineated below 3500 m elevation by using three-dimensional visualization technology.The longitudinal length of the anomaly ranges from 30 to 60 m,with the deepest depth at about 625 m.The maximum abnormal lateral width at tunnel mileage K31+620—K31+680 is about 45m,and the maximum abnormal lateral width at tunnel mileage K33+585—K33+620 is about 85 m.In this paper,the structure,lithology,poor geological body and distribution range of anomalies in the tunnel crossing area are accurately identified by the comprehensive geophysical exploration method,which provides a basis for the design of the tunnel and puts forward suggestions for the subsequent construction of the tunnel,which has certain reference significance for similar projects.

关 键 词：公路隧道 EH_(4)大地电磁测深法 钻孔地球物理测井 水压致裂法地应力测试 高精度勘察 三维立体成图 

分 类 号：P631[天文地球—地质矿产勘探]