Abstract:

The use of magnetic resonance sounding in prediction of water bearing structures in front of a tunnel face was proposed in order to realize the effective detection of water in front of a tunnel face. A homogeneous conductive full space was used as the basic model. The distribution of harmonic electromagnetic response was calculated. Distribution of the magnetic resonance toppled angles in magnetic resonance sounding(MRS) detection on tunnel face was also simulated. The modeling result showed the obvious MRS response from the water in front of a tunnel face, while the amplitude was very small. According to the characteristics of MRS detection in tunnels, it was proposed that the currently cosine excitation source could be replaced with step source and the current receiver coil could be replaced with magnetic probe. MRS is a potential method to detect water and distinguish water and mud.

Key words: tunnel advanced geology prediction, magnetic resonance sounding (MRS), magnetic resonance toppled angle, direct detection of water bodies, feasibility