西部大采高工作面保护煤柱宽度优化研究

Study on optimization of protective coal pillar width on large mining height working face in western China

保护煤柱尺寸一直是三下开采研究的热点问题,特别是在西部大采高软弱覆岩特厚煤层开采条件下,其对地表建筑物安全的影响有待进一步研究。以榆树湾井田20119工作面为例,综合利用数值模拟和概率积分法确定了合理保护煤柱宽度,并进行现场验证。结果表明:随着煤柱宽度的减小,地表沿X方向的水平移动呈现倒“S”型趋势,沿Y方向的移动呈现倒“U”型趋势,地表的最大下沉量随煤柱宽度的减小而不断减少;结合概率积分法对保护煤柱宽度进行预计,确定优化后的煤柱宽度为180 m;对现场村庄进行实时监测,地表下沉和倾斜值均满足现场施工要求,验证了保护煤柱宽度的合理性。

The size of protective coal pillars has always been a hot topic in research on mining under buildings,railways and waters.Its impact on the safety of surface buildings,especially under the conditions of large mining height and high-strength soft overburden thick coal seam mining in western China,needs to be further studied.Taking the 20119 working face in Yushuwan well field as an example,this study first determined the reasonable width of protective coal pillars through a combination of numerical simulation and probabilistic integration method and carried out an on-site verification.The results show that as the width of the coal pillar decreases,the horizontal movement of the surface along the X direction shows an inverted“S”trend,and the movement along the Y direction shows an inverted“U”trend,and that the maximum subsidence of the surface decreases with the decrease of the width of the pillar.Then,the probability integral method was used to predict the width of the protected coal pillar.The optimized width of the coal pillar was determined to be 180 m.Finally,the real-time monitoring of the on-site village was carried out and the results show that the values of surface subsidence and inclination meet the requirements of the on-site construction,verifying the reasonableness of the protection of the coal pillar.