隧道瞬变电磁多点阵列式探测方法研究  

RESEARCH ON TRANSIENT ELECTROMAGNETIC MULTIPOINT ARRAY DETECTION METHOD IN TUNNEL

作　　者：孙怀凤[1] 李术才[1] 李貅[2] 戚志鹏[2] 苏茂鑫[1] 薛翊国[1] 郭文波[3] 刘人太[1] 韩伟伟[1] 

机构地区：[1]山东大学岩土与结构工程研究中心,山东济南250061 [2]长安大学地质工程与测绘学院,陕西西安710054 [3]西安交通大学,电子与信息工程学院,陕西西安710049

出　　处：《岩石力学与工程学报》2011年第11期2225-2233,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金重点项目(51139004);国家自然科学基金青年科学基金项目(50908134);山东大学优秀研究生科研创新基金项目(YYX10014)

摘　　要：针对传统的隧道瞬变电磁探测与解释仅主要依靠二维视电阻率断面图的不足,借鉴地面大回线中心装置瞬变电磁的观测方式,提出隧道瞬变电磁多点阵列式探测方法。研究瞬变电磁非中心点垂直分量频率域响应双重贝塞尔函数强振荡型积分的计算方法,以中心点频率域响应多项式为基函数,定义多项式形式的非中心点频率域响应表达式,通过最小二乘拟合的方法得到多项式系数。推导瞬变电磁非中心点时间域响应公式,在瞬变电磁场晚期近似条件下,给出非中心点垂直分量晚期视电阻率公式,实现隧道瞬变电磁探测时观测回线内非中心点垂直分量响应能够转换为视电阻率图像进行解释,为隧道瞬变电磁多点阵列式探测提供理论基础,提出利用隧道瞬变电磁阵列式探测响应数据进行三维视电阻率综合解释的方法。在理论研究的基础上,结合现场试验,开展隧道瞬变电磁多点阵列式实际探测研究,对隧道底板下方含水构造进行多点阵列式探测,对探测结果进行对比和解释,形成三维视电阻率图,分析得到含水构造的三维空间展布规律。Aiming the limit of traditional transient electromagnetic method（TEM） detection in tunnels only depending mainly on 2D apparent resistivity, a method of transient electromagnetic multipoint array detection in tunnels is presented learning from the fixed-loop survey method when detecting on the ground. The calculation method of high oscillation dual Bessel integration in frequency domain TEM response of non-central vertical component is studied. Taking the polynomial of center component in frequency domain as a basis function, a polynomial of non-central vertical component in frequency domain is defined; and the polynomial coefficients are obtained by least square fitting. The formula of non-central vertical component in time domain is derived. The late-time apparent resistivity of non-central vertical component is also derived according to the late-time approximate conditions of transient electromagnetic field. Transform of non-central vertical component of TEMdetection in tunnels into apparent resistivity image is realized. It is the basic theory for transient electromagnetic multipoint array detection method in tunnel. The interpretation method using three-dimensional（3D） apparent resistivity images combining the multipoint response is also proposed. On the basis of the theory studies, transient electromagnetic multipoint array detection method is studied combining the field test in one tunnel. The transient electromagnetic multipoint array detection method for water bearing structure under the tunnel floor are carried out; and the comparison and interpretation are also given about the detection results. A 3D apparent resistivity image is formed; and the 3D space distribution law is obtained by analyzing the 3D apparent resistivity image.

关 键 词：隧道工程 隧道含水构造 瞬变电磁场 多点阵列式探测 视电阻率 

分 类 号：U45[建筑科学—桥梁与隧道工程]