Long Tunnel Of The Deep Electromagnetic Sounding Method Applied Research

It is an important forward topic that the geophysical macroscopic estimation of the deep, big, long tunnel, as well as it has much challage to be ugrently resolved. This paper launches the research that tightly combining the rapid development of the railway engineering and the highly increasing of the number of the deep big long tunnel engineering. At the same time, the paper aims at the applied effects of the Magnetotellurics sounding in this kind of tunnel. Firstly, the paper describes in brief the evolvement and studying foreland in the deep big long tunnel in developed countries, then put forward the high-frequency Cultural Magnetotellurics sounding method (CMT) based on the Magnetotellurics sounding theories. The paper summarizes the CMT frequency spectrum characteristic combining the field observed data, and analyzes the noise source and interference characteristic of the CMT and the CSAMT (Controlled Source Audio-frequency Magnetotellurics). Then, combining the actual engineering application, the paper carries on contrast research about the technique routes of the two representative MT method , discussing in detail the static effects and it's correction, the static effects result from the earth's surface inhomogeneous medium and the topographic inequality. The resolution problems and the prospecting depth problems of CMT and CSAMT discussed too. Secondly, after analyzing and contrasting the applied effects in TE model and TM modelof the CMT method, the paper studies the near field effect, transitional belt effect and shadow effect of the CSAMT and method. In the fifth chapter, the paper studies the cavern detection and fault orientation by CMT and CSAMT methods, combining the railway engineering survey of Yichang - Wanzhou railway. The paper carries on thorough research on the applied conditions, data processing, theories of geophysical explanation of CMT and CSAMT. It is a good indicator for this kind of engineering design aftertime. At last, the paper studies originally to the source of the useful conclusions, in the last of the paper, the author summarizes in brief the results of the paper and put forward some suggestions for the future work.