倾斜煤层软岩巷道底鼓机理分析及控制技术

Mechanism Analysis and Control Technology of Floor Heave Occurred in Mine Soft Rock Gateway in Inclined Seam

以清水营煤矿110202工作面辅助运输巷为研究对象,分析得出倾斜煤层软岩巷道底鼓的主要影响因素。根据巷道外接圆理论和朗肯土压力理论,建立倾斜煤层巷道底鼓力学模型,推导出倾斜巷道底板围岩压力公式,得出倾斜巷道底鼓力学机制:巷道顶板和两帮松动岩体的垂直应力向下传递,在底板岩层中形成水平挤压应力,当底板被动塑性区内的底板围岩压力大于围岩强度时,底板破坏并向巷道临空区移动,形成底鼓。提出倾斜煤层巷道底鼓控制的"顶板—两帮—底板"系统结构支护方式,并运用到清水营煤矿110202工作面辅助运输巷,数值模拟结果显示:该方法能够有效地控制倾斜煤层巷道底鼓的发生。

Taking the auxiliary transportation gateway of No. 110202 coal mining face in Qingshuiying Mine as a study object, the paper analyzed and obtained the main influence factors of the floor heave occurred in the mine soft rock gateway in the inclined seam. According the circumcircle theory of the gateway and the Rankine earth pressure theory, a mechanics model of the floor heave in the inclined seam gateway was established, the floor surrounding rock pressure formula of the inclined roadway was deduced and the mechanics mechanism of the floor heave in the inclined gateway was obtained. The vertical stresses of the gateway roof and the two sidewall loose rock were transferred downward. Horizontal compressive stress would be occurred in the floor strata. When the floor surrounding pressure within the floor passive plastic zone was higher than the surrounding rock strength, the floor failure would move forward to the free space of the gateway and thus the floor heave would be caused. A ＂roof - two sidewalls - floor＂ system structure support mode was provided to control the floor heave of the gateway in inclined seam and was applied to the auxiliary transportation gateway of No. 110202 coal mining face in Qingshuiying Mine. The numerical simulation results showed that the method could effectively control the floor heave occurred in the inclined seam gateway.