龙固煤矿采场底板突水因数与突水危害性分析

Water-inrush-factor and Its Application in the Analysis on Harmfulness of Water-inrush in the Longwall Mining in Longgu Coal Mine

利用煤矿底板突水因数表述了层状岩体渗流失稳条件。根据龙固煤矿的岩层柱状图,运用RFPA2D软件计算了采场推进到25 m和50 m时底板岩层的应变分布,并利用渗透特性与应变之间的关系,计算了相应的底板突水因数。研究表明:岩层的破坏造成渗透率的增大、非Darcy流β因子和加速度系数的减小,从而使突水因数增大,突水发生的危险性增大;随着工作面的推进,底板的破坏范围扩大,变形也相应地增大,突水因数增大;当推进到25 m时,底板突水因数为95.1%;当推进到50 m时,底板突水因数为619%。

A definition of water-inrush-factor was presented, and the criterion about the instability of seepage flow of water in stratified rock mass was described by water-inrush-factor. Based on the column of rock mass in Longgu coal mine, the distributions of stress in mining floors were simulated by using the numerical testing machine （RFPA） at the moment when longwall mining was pushed on to 25 meters and 50 meters respectively, and the water-inrush-factors were calculated on the basis of the relationship between permeability parameters and strain. It was shown that when the permeability raised, the non-Darcy flow β factor and acceleration coefficient decreased as the failure of the mining floors, and the water-inrush-factor raised subsequently. As the longwall mining was pushed on, the destroyed district extended, and the strain and water-inrush-factor increased correspondingly. For the mining floor in Longgu coal mine, the water inrush-factors were 95.1% and 619% when the working face was pushed on to 25 meters and 50 meters respectively.