【摘要】 研究目的:近年来,对于长大深埋铁路隧道的工程地质勘察,大地电磁法已经成为目前最为行之有效的物探勘察手段之一。大地电磁法利用天然电磁场信号为场源,观测天然电磁场的时间序列信号,然后将时间序列数据转化为频率域数据,进而计算出每个频点的电阻率值和阻抗相位。野外数据经Robust处理和带地形的一维反演,能真实地反应地下的地质信息。研究结论:在中条山选线研究中,应用天然源音频大地电磁法(AMT)进行物探勘察,基本查明了测区内地层情况及一些不良地质体,达到预期勘察目的。本次中条山隧道勘察,共推断物探I类异常11处,物探II类异常8处,断层分别为F2,F3,F4,施工时应加以注意。大地电磁法以天然大地电磁信号为场源,具有野外施工简便,成本低廉,探测深度大的优点。音频大地电磁法由于频率较高,对浅部的分辨率较高,更适用于工程勘察,对本次中条山隧道的勘察取得良好效果。更多还原

【Abstract】 Research purposes: In recent years,the magnetotelluric method has become one of the most common and effective ways for the geophysical exploration for the long and deep-buried railway tunnel.The magnetotelluric method uses the natural electromagnetic signal as the field source to observe the time serials of the natural electromagnetic signal and compute the value of resistivity and its impedance phase by transforming the observed data from time domain to frequency domain.After the Robust processing and 1-d inversion of the topography are conducted,the field data can actually reflect the underground geological information precisely. Research conclusions:In the research on the alignment of the Zhongtiaoshan Tunnel,the natural source audio frequency magnetotelluric was used for the geophysical exploration to find out the stratum condition and unfavorable geological structures in the survey area,achieving the expected survey target.During the exploration for the Zhongtiaoshan Tunnel,the 11 Class-I geophysical abnormalities,8 Class-II geophysical abnormalities and faults of F2、F3、F4 were deduced,and to them the more attention would be paid during construction.The magnetotelluric method has the featurs of simple out-door application,low cost and deep depth detecting due to using the natural MT signal as the field source.As the AMT uses higher band frequencies,it has higher resolution in the shallow areas.It is available for the engineering investigation,and the desirable results of the explorartion for the Zhongtiaoshan Tunnel was achieved.更多还原