复杂围岩大断面回采巷道底鼓控制研究

 底鼓是复杂围岩环境下巷道破坏的主要特征之一。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，取得了显著的经济和社会效益。

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

Floor heave is one of the main features of roadway damage under complex surrounding-rock environment. The finite difference procedure FLAC3D is used to simulate floor heave of auxiliary haulage roadway at fully mechanized face 110202 in Qingshuiying coal mine, and the laws of deformation and movement and stress distribution around the roadway are obtained. And the mechanical mechanism of floor heave is proved as follow: the bearing arch structure is formed in roof after roadway extraction, through which the load of overlying rock is transmitted to sides of roadway with stress concentration. Under constraint of concentrated stress of sides, the active and passive plastic zones are formed by horizontal compressive stress in floor. When the surrounding rock pressure of floor in passive plastic zone exceeds its strength, stress instability of floor is caused and floor heave is formed. In addition, the roof-sides-floor system structure support pattern is proposed for controlling floor heave of roadway under complex surrounding-rock environment. The experiment of this support method shows that good effect of floor heave controlling is obtained with good technical and economical performances.