浅埋煤层大采高工作面支架合理初撑力确定

Determination of support setting load of large-mining-height longwall face in shallow coal seam

针对浅埋大采高工作面煤壁片帮控制问题,以陕北某矿大采高工作面为背景,采用理论分析、数值计算和物理模拟相结合的方法,研究了支架初撑力对煤壁稳定性的影响规律。基于“支架-煤壁-顶板”采场结构力学模型,发现支架初撑力的提高,能快速提升支架工作阻力,有效减小煤壁受力,减轻煤壁片帮程度及发生的概率。数值模拟表明:随着初撑力的增加,煤壁塑性区范围减小,煤壁水平位移和顶板下沉量减小,煤壁片帮减轻。考虑大采高工作面等效直接顶静载作用和高位台阶岩梁结构的稳定性,按照控制等效直接顶和保持与额定工作阻力的合理比例关系,给出了基于片帮控制的合理支架初撑力确定方法。

In order to solve the coal wall spalling control issue of large-mining-height longwall face in shallow seam, this study concentrates on a large-mining-height longwall face in the north of Shaanxi province. The effect of support setting load on coal wall stability is studied by using theoretical analysis,numerical calculation and physical simulation. Based on the integral "support-coalwall-roof" model, it is found that the support working resistance rapidly increases with the increase in support setting load.Thus the pressure and spalling probability of coal wall could be reduced effectively. Numerical simulation shows that the plastic zone and horizontal displacement of coal wall decrease with the increase in support setting load. Meanwhile, the roof subsidence and coal wall spalling are also reduced. Taking into account the equivalent immediate roof and stability of high step rock beam structure of large-mining-height face, the determining method of reasonable support setting load for spalling control is put forward based on the weight of equivalent immediate roof and reasonable proportional of rated working resistance.