初采期工作面推进速度对近距离煤层的影响

Influence of Advance Speed of Mining Face on Close-distance Coal Seam in Initial Mining Period

为了研究初采期工作面推进速度对近距离煤层的影响,运用3DEC离散元数值模拟软件模拟分析初采期不同推进速度下近距离煤层的沉降特征、离层特征以及应力分布特征。结果表明:推进速度越快,初次来压步距越大;推进速度越快,采空区离层区扩张越快,扩张范围越大,而稳定的速度越慢;快速推进对近距离煤层超前工作面区域扰动较大,但不能满足离层的时效性,因而在中速推进条件下,超前工作面区域离层范围最大;顶板初次垮落后,采空区上方近距离煤层应力区主要由拉应力区、压实区、卸压区组成;推进速度越快,回采工作面附近的拉应力区出现位置离回采位置越远,范围越小。推进速度越快,压实区范围越小,卸压区范围越大。

To study the influence of the advance speed of mining face on the close coal seam in initial mining period,settlement characteristics,separation characteristics and stress distribution characteristics of the close-distance coal seam at different advance speed of the mining face in initial mining period were analyzed by using 3DEC discrete element numerical simulation software.The results show that:the higher the advance speed is,the larger the first weighting interval is;the higher the advance speed is,the faster the goaf separation zone expands,the bigger the expansion range is,but the lower the steady speed is;rapid mining can perturb the front of the mining face in the close distance coal seam to some extent,but because of the time effect of the separation,the separation zone of the front of the mining face is largest when the mining is at a medium speed;after the roof collapses at the first time,the stress zone of the close-distance coal seam near the goaf mainly consists of tensile stress zone,compaction zone and pressure relief zone.The higher the advance speed is,the farther the tensile stress zone appears from the mining position,and the smaller the tensile stress zone is.The higher the advance speed is,the smaller the compaction zone is,the bigger the pressure relief zone is.