Application Study Of CSAMT In Deep And Long Tunnel

Deep and long Tunnel Engineering Geology macro forecast is still urgent to solve as a major topic research in the engineering world today.Controlled Source Audio-frequency Magnetotelluric(CSAMT) has the detection depth,not high resistance layer of shielding,the high horizontal resolution can be sensitive to find fault,anti-interference ability,high efficiency,low cost of work and field equipment,lighter, etc.,so the method of CSAMT can be widely used in engineering Exploration.This thesis combined the Mo Daoshi and Han Xinling tunnel,carried out CSAMT research and application in the detection of deep and long tunnel.Successfully explained the lithology,geological structure,the water situation of the deep and long tunnel,combined with regional geological data,divided the tunnel level,for the tunnel design and construction provid the basis.Reduced drilling and mountain workload, reduced inspection cycle,to a certain extent,reduced the cost to fill the difficult geological drilling site blank.This thesis also analyzed and summarized the effects of static factors:static body buried depth,horizontal width,thickness and resistivity and and the length of the dipole electric measurement.The method of correction mainly has:spatial filtering, time-frequency separation and repression,static correction phase method,using magnetic phase measurement data for static correction,joint inversion,2D modeling simulation,direct 2D inversion,EMAP.Based on actual survey objectives,determined the distance and the transceiver operating frequency of CSAMT.By analyzed and combined CSAMT in the application of Mo Daoshi and HanXinLing tunnel,We have the following conclusions:1.Based on exploration targets, appropriately choose the communication distance and frequency.2.Probing deep goals, should choose the larger MN, while the Ministry for the small shallow geological targets, MN should choose smaller.3. CSAMT method can accurately judge strati graphical lithology, geological structure and groundwater storage conditions.4.CSAMT is bad to the shallow layer resolution.