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

摘要： 文中介绍了利用地下全空间瞬变电磁(UWTEM)技术在某煤矿-250排水巷道掘进过程中进行的连续跟踪超前探测试验。根据初探结果,采用不共面同轴偶极观测方式时,UWTEM在巷道掘进头前方的有效探测范围约为70m,巷道每掘进50m进行一次跟踪探测。试验表明,利用该技术可以有效地超前预测煤矿巷道掘进头前方30～50m范围的富水异常,为及时采取水害治理措施提供依据。

关键词: 地下全空间, 瞬变电磁, 超前探测, 水害预报