密实充填矿压显现时空演化规律研究

建立和分析密实充填矿压显现时空演化力学模型,运用相似材料模拟方法研究充填开采条件下的采场矿压显现时空演化规律,并以邢台某矿充填实践为工程实例进行分析验证。研究结果表明:顶板下沉活跃期间,充填体受力与充填步距和推进时间呈正相关;在充填开采物理模拟中,顶板测点应力普遍经历了应力升高–急剧卸压–缓慢升压再到稳定的过程,且工作面前方顶板应力峰值和煤柱受力随着充填步距的增加而增大;充填体受力随着工作面推进而不断增加至趋于稳定,稳定后的顶板应力和充填体受力均小于原岩应力;停采后静置阶段,随着时间增长,充填区顶板依然存在缓慢下沉现象。某矿充填实测结果显示距离切眼15和40 m处的充填体压力为3.5和5.5 MPa,且顶板下沉和覆岩离层在工作面推进过程中均随着充填距离的增加和充填时间的推移表现出了规律性变化。

Study on space-time evolution law of strata behaviors under compacted filling

A mechanical model of space-time evolution of strata behaviors in compact filling is established and analyzed.Similar material simulation method is used to study the space-time evolution law of strata behaviors in stope under filling mining conditions,and the filling practice of a mine in Xingtai is illustrated as an engineering example.The results show that,during the active period of roof subsidence,the force acting at the filling body is positively correlated with the filling step and the advancing time.In the physical simulation of backfill mining,the stress of roof measuring points generally experiences a process of stress rising,rapid pressure relief,slow pressure rise and stabilization,and the peak stress of the roof in front of the working face and the force of the coal pillar increase with increasing the filling step.During advancing of the working face,the force of filling body increases continually and finally tends to be stable,and the roof stress and the force of the filling body after stabilization are less than the original rock stress.In the static stage after stopping mining,the roof of the filling area still subsides slowly with time.The measured results of the mine show that the pressures of the filling 15 and 40 m from the cut-hole are respectively 3.5 and 5.5 MPa and that the roof subsidence and overburden separation show regular changes with increasing the filling distance and the advance of the filling time.