Investigation on Mining-Induced Floor Water Inrush from Column and Its Control Based on Microseismic Monitoring

Water inrush is the biggest threat for safe mining in the Ruifeng coalmine, located in North China. In the study mining area, the floor water inrush is mainly caused by mining activities and collapse column. In this article, the mechanical criteria of floor water inrush are obtained based on cusp catastrophe theory, which is used to assess floor water inrush risk in the Ruifeng coalmine. Theoretical analysis shows that floor water inrush is very likely to occur during coal mining without the influence of geological structures. Additionally, FLAC(3D) was used to simulate the damage of floor strata during the mining face advances. Numerical results show that the water inrush channel occurs in front of the mining face due to the influence of stress concentration. Therefore, a microseismic monitoring system was applied to monitor the formation of water inrush pathway. Field monitoring results show that two water inrush pathways were accurately predicted and positioned. Based on the microseismic monitoring results, target grouting was adopted to prevent water inrush. This study provides significant guidance for the prevention of floor water inrush.