基于随机介质理论的综放开采顶煤放出规律

摘要

顶煤的放出特征对综放开采采出率和含矸率有重要影响.基于模型试验,考虑综放支架影响,首先拟合出顶煤沉降曲线极值点偏移公式,依据随机介质理论建立了煤矸分界线和顶煤放出体方程.结果表明:支架尾梁的限定作用和放煤口导致放出条件的突变对煤矸分界线及顶煤放出体形状有重要影响,煤矸分界线在远离支架处表现为较标准的漏斗曲线,靠近支架处渐变为凸型曲线,靠近放煤口处则表现为向尾梁方向勾折;放出体在放出高度较小时呈向尾梁后上方倾斜的不规则状,轴偏角较大,随着放出高度增加,放出体呈前下方被尾梁切割的变异类椭球体状,轴偏角减小并稳定为零,支架尾梁后上方顶煤是综放开采所放顶煤的主要组成部分.%The top-coal drawing has a significant impact on the recovery ratio and rock mixed ratio in longwall top-coal caving mining.Based on a model experiment conducted,firstly the offset formula of top-coal settlement curve extreme point was fitted with the consideration on the influence of shield beam,and then the boundary of top-coal and drawing body equation were built with stochastic medium theory.The results show that the shield beam and drawing opening have an important influence on the shape of boundary and drawing body of top-coal.The boundary of top-coal presents standard funnel plots in the places away from shield beam,and changes into convex curve gradually near shield beam,while in the places near drawing opening,the boundary of top-coal bends to shield beam.When the caving coal height is small,drawing body leans forward to top after shield beam and the shape is irregular,as well as the axial deviation angle is relatively big.With the increase of caving coal height,the shape of drawing body presents quasi-ellipsoid and its anterior inferior part is cut by shield beam,and the axial deviation angle reduces to 0,the coal at the top after shield beam is the major component of drawn top-coal.