新安矿有8.00×10^7t煤炭资源处在小浪底水库水体之下,煤厚变化大(0.0~18.8m),现有的导水裂隙高度计算方法不能满足水体下采煤安全评价的要求,水体下采煤存在突水隐患。为确定开采过程中覆岩破坏上限及其是否导通地表水体,研究区在5个地面钻孔中进行超声成像观测,在5个井下钻孔中进行并行网络电法CT观测,并通过物理模拟和数值模拟进一步研究各种不同开采条件下的覆岩破坏过程。观测及模拟结果表明,导水裂隙发育最大高度主要取决于煤层采厚,两者之间为非线性关系,在此基础上给出相应计算公式,为结合其他突水影响因素确定安全可采分区提供可靠依据,并得到3个位于安全可采区内的工作面工业性试采成功的验证。
There are over 80 million tons coal under the water body of Xiaolangdi Reservoir in Xin'an coal mine area, China's Henan Province. The coal thickness changes from 0.0 m to 18.8 m: therefore, it is difficult to calculate exactly the height of water flowing fractured zone that may cause water disaster by using the known methods. In order to determine the upper limit of water flowing fractured zone, ultrasonic imaging technology is used in 5 ground surface boreholes; and the parallel network electrical CT technology is used in 5 boreholes in the coal mine to observe the failure process and the maximum height of water flowing fractured zone. Furthermore, physical and numerical simulations are also used to observe the height in more different excavating cases. The detecting and simulation results demonstrate that the height of water flowing fractured zone is mainly determined by coal thickness excavated in a nonlinear relationship. A formula is given based on this research: and it is used to determine the safe area while mining under the water body of Xiaolangdi Reservoir with combination of other affecting factors of water inrush. The result is verified to be reliable by successful industrial mining experiments of three working faces in the safe area.