采空区边缘下方回撤通道护巷煤柱合理宽度研究
Study on reasonable width of coal pillar in retracement channel under goaf edge
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摘要: 为了研究浅埋近距离煤层中下煤层回撤通道护巷煤柱合理留设宽度,采用理论分析、相似模拟和数值模拟的研究方法,研究了下煤层回撤通道护巷煤柱覆岩结构特征,确定了采空区边缘下方回撤通道护巷煤柱合理留设宽度。研究表明:在上煤层开采完毕后,由于上煤层停采线煤柱的原因,下煤层回撤通道因布置位置不同将造成护巷煤柱的覆岩结构存在较大差异,从而导致煤柱所承载的荷载出现不同;在煤柱宽度留设时,从采空区压实区到卸压区应逐渐减小,从卸压区到上煤层实体煤下应逐渐增大,采空区压实区煤柱宽度应小于实体煤区。通过建立工况条件下采空区边缘下方回撤通道数值模拟模型,确定了护巷煤柱合理留设宽度为18 m。Abstract: In order to study the reasonably reserved width of the coal pillars in the roadway for lower and middle coal seams in shallow and short distance coal seams, the research methods of theoretical analysis, similar simulation and numerical simulation were used to study the characteristics of the overburden rock structure of the coal roadways for the roadways in the lower coal seams. To determine the reasonable width of the coal pillars for the roadway under the edge of the goaf, the studies show that: after the completion of the mining seam, due to the coal pillar of the stop-mining line of the upper coal seam, the different layout positions of the retracting passage of the lower coal seam will lead to the great difference in the overburden structure of the coal pillar of the roadway, thus resulting in the different load of the coal pillar; when the width of coal pillar is set, the width of coal pillar in the goaf compaction zone should gradually decrease from the pressure relief zone to the pressure relief zone and gradually increase from the pressure relief zone to the solid coal in the upper coal seam. The width of coal pillar in the pressure relief zone should be smaller than the solid coal zone. By establishing the numerical simulation model of the retracement passage below the goaf edge under working conditions, the reasonable width of the coal pillar is determined to be 18 m.