关键词: 地下全空间, 瞬变电磁, 超前探测, 水害预报

Abstract: Accurate prediction of geohazards far in advance of engineering works is a fundamental requirement in underground mining. Underground whole-space transient electromagnetic (UWTEM) method was tested at the driving face of a drift in a coal mine for detecting water-bearing zones ahead of tunneling. Having experimentally determined that the sounding depth is about 70m for a configuration of coaxial off-set loops in the drift, the UWTEM experiment was designed as such that measurements were made ahead of each time the drifting operation progressed 50m. The measurements were analyzed at each step. The results proved that the structures rich of water 30～50m ahead of the driving face can be effectively predicted, which is helpful for preventing the occurrence of water disasters during mining. However, the experiments show that false anomalies would sometime appear due to the effects of conductors behind the driving face, and that the adopted loop configuration could not be used in small drifts since the receiver- transmitter coil separation should be greater than 5m.

Key words: underground whole-space, transient electromagnetic method, leading detection, prediction of water disasters