复杂围岩大断面回采巷道底鼓控制研究

Study on Floor Heave Control of Large Cross Section Mining Gateway with Complicated Surrounding Rock

采用有限差分软件FLAC3D对清水营煤矿110202工作面辅助运输巷道底鼓进行模拟,分析其位移、应力分布特征,得出其底鼓力学机理:巷道开挖后,在巷道顶板中形成拱形承载结构,上覆岩层重量通过拱形承载结构传递到巷道两帮,在两帮产生应力集中,在两帮垂直集中应力的约束下,底板受水平挤压作用形成主被动塑性区,当底板塑性区围岩压力大于围岩强度时,巷道底板发生应力失稳,产生底鼓。提出复杂围岩环境下巷道底鼓控制的"顶板—两帮—底板"系统结构支护方式,试验结果表明该支护方式取得了良好的底鼓控制效果。

A finite difference software FLAC3D was applied to simulate the floor heave of the auxiliary transportation gateway in No. 110202 coal mining face of Qingshuiying Mine and to analyze the displacement and stress distribution features. The mechanics mechanism of the floor heave was obtained. After the gateway excavated, an arch loading structure was formed in the roof of the gateway. The weight of the overburden strata, with the arch loading structure, would be passed to the two sidewalls of the gateway. The stress concentration were occurred in the two sidewalls. Under the restraint of the vertical concentrated stresses in the two sidewalls, a main passive plasticity zone was formed in the floor with the horizontal extrusion role. When the pressure of the surrounding rock in the plasticity zone of the floor was higher than the strength of the surrounding rock, the gateway floor would have a stress stability lost and a floor heave would be occurred in the gateway. A ＂roof - two sidewalls - floor＂ system structure support method was provided to control the gateway floor heave under the complicated surrounding rock environment.