A review on the progress of the underground nuclear magnetic resonance method for groundwater disaster forecasting detection of tunnels and mines

This review focuses on the recent progresses of the nuclear magnetic resonance (NMR) method for groundwater disaster forecasting detection of tunnels and mines. The use of NMR technology to solve the problems caused by water inrush in mines and tunnels has attracted the attention of researchers. During the last decade, the NMR technology applied to the underground early detection of water has become a new branch named as underground nuclear magnetic resonance (UNMR). Although the UNMR method is not a perfected method due to the confined one-dimensional inversion results and the ability to detect only large volumes of water, it can give a relatively reliable estimate of water content at different distances. Thus, the UNMR method is a powerful method for forecasting the disaster water. This paper starts with the review of the recent literature and introduce the highlights. Then the representative progress and two case studies of the UNMR method are described in detail. Finally, we give some suggestions for further research on the UNMR method.