强矿压工作面回撤通道失稳机理与注浆加固技术

Instability mechanism and grouting reinforcement technology of retreat channel in high mine pressure working face

为保证末采期间回撤通道的稳定性,实现安全高效的工作面回撤,以布尔台煤矿22206综采工作面为工程背景,对末采期间回撤通道围岩加固技术进行了研究。采用理论分析的方法建立了末采期间剩余煤柱力学分析模型,得到煤柱极限稳定时剩余煤柱宽度计算方法,确定了最佳注浆时机对应的位置。同时对比分析了注浆前后煤岩体单轴压缩应力应变曲线,得到注浆可有效提高煤岩体强度。最后结合布尔台煤矿22206综采工作面情况进行计算,确定工作面末采期间主回撤通道内最佳注浆时机为剩余煤柱宽度10.1m时,进一步设计了注浆参数开展了剩余煤柱注浆,结果表明,工作面末采期间对主回撤通道正帮及顶板注马丽散NS加固材料,能有效控制回撤通道剩余煤柱和顶板的稳定,实现安全高效、经济合理地搬家倒面。

In order to safely and efficiently withdraw working face equipment, taking 22206 fully mechanized working face of Buertai Coal Mine as the engineering background, the grouting reinforcement technology is proposed for the withdrawal channel of working face based on theoretical analysis and field measurement. By establishing the mechanical model of the residual coal pillar in end mining, the stability of the residual coal pillar is analyzed and the appropriate width of the residual coal pillar at critical status is determined, that is the optimal grouting timing. Through comparing the experimental results of uniaxial compressive strength before and after grouting, it is concluded that grouting reinforcement technology can improve the bearing capacity of coal and rock mass significantly. Finally, combined with the specific situation of 22206 fully mechanized working face in Buertai Coal Mine, the optimal grouting time in the main withdrawal channel during the end mining is when the coal pillar is 10.1 m wide. The results are applied to engineering practice and the expected effect is achieved. Grouting Marisan NS into the front side and roof of the main withdrawal channel during the final mining period can control the stability of the coal pillar and roof, and realize the safe, efficient and economic working face shifting.