基于“顶板-煤壁-支架”综合评价的大采高支架工作阻力研究

针对6.0 m特大采高综采工作面支架适应性评价与工作阻力确定难题,基于大采高采场覆岩"悬臂梁-层间岩层-砌体梁"结构模型,对6.0 m特大采高综采工作面支架合理工作阻力进行了确定,通过数值模拟和大比例尺采场相似模拟实验对支架与围岩控制适应性进行了验证和评价。研究结果表明,大采高综采支架工作阻力的确定要以满足顶板、煤壁等采场围岩控制为前提,并需确保支架良好的位态。支架工作阻力不仅要能支撑垮落带关键层"悬臂梁"破断长度内的岩层载荷,还要能给断裂带下位岩层"砌体梁"结构以平衡力。模拟结果表明,当工作阻力低于10 000 k N时,支架处于满负荷运转状态,活柱下缩量较大,顶板及煤壁变形显著;当工作阻力高于11 000 k N时,采场围岩及支架工况显著改善,据此确定支架合理工作阻力为12 000 k N。生产实践表明,试验工作面支架循环末阻力8 340~10 247 k N,安全阀开启率低于5%,煤壁完整性较好,支架工作阻力满足顶板支护及安全生产要求。

Determination of large-height support resistance based on multi-factor analysis

In response to challenge of adaptability of support and working resistance in large-height working face,the “cantilever beam-sandwich-voussoir beam” structure model is established,and the preliminary scheme of support resistance is calculated,which is verified by both numerical simulation and large-scale physical modeling.The study shows that the working resistance should meet the supporting demands of roof and rib,and keep itself with good position.The working resistance consists of two parts:one part is to bear the weight of cantilever beam due to breakage of key strata in caving zone；and the other is to balance the voussoir beam structure located in lower strata of fissure zone.When the working resistance is lower than 10 000 kN,the support operates at full capacity,and the deformation of surrounding rock increases distinctly；when the rated resistance higher than 11 000 kN,the indicator decreases distinctly.And the reasonable working resistance is determined to be 12 000 kN,which is verified feasible by the production practice.In mining practice,the terminal resistance is 8 340-10 247 kN and the percentage of safety valve opening is below 5%,so the scheme can meet the production requirements.