高频大地电磁法在戴云山隧道围岩分级中的应用  

The application of high frequency magnetotelluric method in the rock mass classification of Daiyunshan tunnel

作　　者：段圣龙[1] DUAN Shenglong(China Railway SIYUAN Survey and Design Group Co.,LTD,Wuhan 430063,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《物探化探计算技术》2018年第3期378-383,共6页Computing Techniques For Geophysical and Geochemical Exploration

摘　　要：戴云山隧道由于具有埋深大、洞程长、穿越地质单元复杂多样等特点,地震折射波勘探法难以获得隧道围岩物性参数,其围岩分级效果较差。高频大地电磁测深法具有探测深度大,已成为隧道地质勘察中的一种重要方法。通过地表实施高频大地电磁法观测获取隧道洞深围岩电阻率,利用围岩电性参数计算岩体完整性系数(Kr),进一步采用Kr对戴云山隧道进行围岩分级。对比分析了两种方法的围岩分级效果,结果表明,Kr分级结果与实际开挖情况更为吻合。研究结果表明:基于高频大地电磁法计算的岩体完整性系数Kr可以作为评价深埋隧道岩体完整程度量化指标。Seismic refraction survey methodishardly helpful in determining physical properties of the surrounding rock of the deep buried tunnels due to their great depth,length and geological complexity.The high frequency Magnetotelluric sounding method has thus been a main method in tunnel geological surveys due to its great depth of prospecting.In this paper,the high frequency magnetotelluricmethod is used to obtain the resistivity of deep surrounding rock in tunnel hole,and the rock mass integrity coefficient（Kr）is calculated by using the electrical parameters of the deep surrounding rock.The rock mass classification of Daiyunshan tunnel is carried out by the rock mass integrity coefficient（Kr）,the evaluation results are in good agreement with the actual excavation.The Kr based on the high frequency magnetotelluric sounding method has been subjected to field engineering tests,and the results show that itcan be used as a quantitative index for evaluating rockmass integrality in the deep buried tunnel.

关 键 词：深埋隧道 围岩分级 岩体完整性系数Kr 高频大地电磁法 

分 类 号：P631.4[天文地球—地质矿产勘探]