The Application Of CSAMT In Jinkou River Tunntl Exploration

This article take the JinKou river tunnel construction as an example,use the contuolled-source audio frequency telluric electromagnetic(CSAMT)method to carry on the survery for the pre-construction tunnel.Then,by comparing of a few different terrain correction or inversion methods(eg:1D&2D flat land inversion,space filter,ratio method,with topography 2D inversion,3D inversion and so on).Through the analysis about the collected date,comparing the ability of various approaches to remove the topographic effect and interpretation accuracy,choice the "SCS 2D" which can remove the topography effect perfectly(one ' s of the ith topography 2D inversion),to be a research tool,and uses it for processing and inversing the data.This paper briefly describes the current overview research of long deep tunnel investigation,and then discussed the impact by static effects caused by physical and topographical object and the correction methods?Finally,combined the Jinkou river tunnels of the exploration process,we carry out the controlled source audio-frequency magnetotelluric method in long deep tunnel in the research and application,and made a successful prediction of the tunnel area lithology,geological structure and its water situation for the tunnel design and construction to provide a more scientific basis.