Prevention of Mine-Shaft Failure by Aquifer Replenishment

Over 100 mine shaft failures have occurred in coal mines of the Huang-Huai region of China over the last three decades. While traditional treatment measures are time-consuming and typically require re-application, the approach of maintaining the water level during mining is a promising technique, first employed in 2011 in the Jisan coal mine by injecting groundwater into the aquifer. In this study, this approach has been improved upon and applied to the Dongtan coal mine. The water level in the middle and lower lithological groups was maintained by replenishing water from the upper group. The water replenishment operation was implemented on November 22, 2012; monitoring indicated relief of compressive strain in the shaft wall, suggesting the efficacy of this treatment method. The number of coal mine shafts, either built or under construction, has reached several hundred in the Huang-Huai region, most of which have an alluvium structure similar to the Jisan and Dongtan coal mines. Therefore, the results of this study have the potential for common use in engineering methods to avoid potential shaft damage or failure, as well as the long-term treatment of already fractured shafts.