煤层顶板次生离层水周期突水致灾过程模拟
Simulation on the progress of periodical water inrush caused by burst of water cells formed by overburden strata separation
-
摘要: 为了提高煤层顶板离层水害防治效果,分析了离层水害的动态周期性特征。根据关键层理论,推导出主采煤层覆岩中产生离层的判别式,采用计算机数值模拟手段,模拟了离层形成过程,总结了顶板次生离层水害的周期性特征。研究表明:离层是由于主采煤层的覆岩力学性质差异较大,当煤层开采致使覆岩产生不协调一致的弯曲下沉而产生。随着工作面的推进,离层形成后持续发育至极值,当上方有充水水源时,则形成离层水。此时,若导水裂隙带发育高度凸跃发展导通离层水体时,该离层水将溃入井下造成离层水害。然后离层逐渐压实萎缩,水体流失殆尽。随着煤层顶板周期性破断,离层水害周期性发生。离层动态周期出现的规模各不相同,其中以第1次出现的离层空间规模为最大,对应的离层次生水害亦最大。研究区工作面每推进100 m,离层水害动态发生1次。Abstract: To increase the effect of prevention and control of water hazard formed by overburden stratum separation, the characteristics of dynamic and periodical water inrush caused by the burst of water cells were analyzed.Using mechanical analysis method, combining with the critical layer theory, a discriminant for the produce of overburden stratum separation was deduced.The formation process of bed separation was simulated, and the periodicity of water inrush caused by the burst of water cells was summed up.The study results show that the overburden stratum separation is caused by the bending and sinking of overburden strata inconsistently.With the advance of working face, the separation develops to maximum after formation.When there is enough water above the separation, water formed by overburden stratum separation appears.At this time, if the height of water flowing fractured zone is large enough to guided bed separation water, the water will collapse and cause mine water disaster.Then, the separation will gradually be compacted and shrink, the water will drain up in the end.With the roof of coal seam periodically breaking, water hazard formed by overburden stratum separation appears periodically.The scales of dynamic and periodical overburden strata separation are different.The largest one is the first occurred separation space, and the water hazard is most serious.The water inrush caused by the burst of water cells formed by overburden strata separation happens one time with the length of working face advance 100 m in the research area.