ADVANCED GEOLOGY PREDICTION WITH PARALLEL TRANSIENT ELECTROMAGNETIC DETECTION IN TUNNELLING
LI Shucai1，SUN Huaifeng1，LI Xiu2，LU Xushan2，XUE Yiguo1，SU Maoxin1
(1. Research Center of Geotechnical and Structural Engineering，Shandong University，Jinan，Shandong 250061，China；
2. College of Geology Engineering and Geomatics，Chang'an University，Xi'an，Shaanxi 710054，China)
Abstract：The parallel electromagnetic responses were studied through three-dimensional numerical and physical modelling respectively. Abnormal electromagnetic responses at the planes ahead of and parallel to the tunnelling front were found，leading to the identifying of the existence of water bearing structures. Some water bearing structures being not detected by the electromagnetic responses perpendicular to tunnel front were detected by the parallel one. When large water bearing structures were very near to the tunnelling front，the paralleled electromagnetic field induced twice occurring of the back electromotive force in the fixed time windows，which can be used directly for the identification of water body in real engineering practice. These findings indicated that the parallel electromagnetic responses could be a useful method for advanced geological prediction.
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2014, Vol. 33 
