特厚煤层开采工作面推进速度对矿压显现的影响

Effect of the excavation advancing speed on the strata behavior of the ultra-thick coal seam

为了研究特厚煤层综放工作面推进速度对矿压显现的影响,以同忻矿8106综放工作面为研究对象,采用数值模拟和现场监测,对不同工作面推进速度下的工作面围岩应力和支架工作阻力进行了分析,得到了工作面推进速度与矿压显现之间的关系。结果表明,工作面推进速度越快,超前支承压力峰值越高、峰值点与煤壁的距离越近,工作面来压步距越长、动载系数越大,工作面矿压显现更强。同忻矿强矿压显现在一定程度上与工作面推进速度有关,应适当降低工作面推进速度。

The present article is dedicated to a study on the effects of the excavation advancing speed on the strata behavior of the ultra-thick coal seam for it is of great importance to enhance the safety of the mining face in hoping to improve the production and economic benefits of the coal mine.However,the mining face enhancement has also some negative effects on the strata behavior.In order to make clear the negative effects of the advancing speed on the strata behavior of the ultra thick seam,we have taken the mining faces of No.8106 and No.8100 of Tongxin coal mine as our research target,with the surrounding rock stress and supporting wall＇s resistance analyzed under the different advancing speeds via a numerical simulation and in-situ monitoring.What is more,we have also worked out the relationship between the advancing speed and the strata behavior by using the FLAC3 D Simulation Software.As a result,we have worked out the surrounding rock stress at different advancing speeds（that is,8m/d,6.4 m/d and 4.8 m/d）.Thus,the numerical simulation shows that,with the increase of the mining velocity,the disturbance of the overburdened rock range becomes larger,whilst,with the decrease of the distance between the face and the position of the peak value,the peak value of the abutment pressure also increases.Besides,with the regard of the tendency,the faster the mining face moves on,the higher the pressure arch will be;at the same time,the greater the arch foot stress,the greater the lateral abutment pressure.What is more,the supporting working resistance monitoring situation also indicates that,with the increase of mining velocity,the larger the roof weighting step distance and the continuous length of the roof weight,the greater the dynamic load coefficient will be on the condition that the support load can be reduced with no periodic weighting.Therefore,to some extent,the strong strata behavior of the said mine is closely related with the advancing speed of working face,which should be reduced to ensure the mining safety.