CSAMT has become an economical and efficient exploration method for deep-buried tunnels, but the static effect, near field effect and electromagnetic interference are prominent problems in CSAMT application. Based on engineering practices, the static effect and near-field effect generation mechanism, along with their characteristics and differences before and after correction, are discussed. If the magnetic field changes slightly in the same geological unit, it is proposed that the magnetic rod is placed far away from cultural noise sources. In the case of exploration in the Longbang tunnel, CSAMT anomalies agree well with the fault fracture zone and karst development zone disclosed by drilling, which illustrates the effectiveness of this method.%可控源音频大地电磁法(CSAMT)已成为深埋隧道工程经济高效的勘探手段之一,静态效应、近场效应及电磁干扰是CSAMT应用中的突出问题,文章结合工程实例探讨了静态效应和近场效应产生机制、特点及校正前后的差别.根据同一地质单元内磁场变化微弱的特点,提出了在隧道勘察中避开文化噪声源的方法.在龙邦隧道勘探实例中,CSAMT异常与钻孔揭露的断层破碎带、岩溶发育带对应较好,说明了该方法的有效性.
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