高地应力下巷道底板拱结构分析及其应用

Analysis of arch structure of laneway floor under high ground stress and its application

为解决高地应力条件下煤矿巷道底板易发生底鼓且难以支护的技术问题,以巷道底板隐形拱为研究对象,构建了巷道底板隐形拱结构力学模型,理论分析了高地应力条件下巷道底鼓机理,提出了底板支护方案和支护参数确定方法,并通过工程实例验证了该方法的支护效果。结果表明:巷道底板变形破坏实质为底板隐形拱结构逐步向深部发育的过程,底板隐形拱的形态与底板岩层所受水平侧压力和两帮支承压力相关,具体表现为竖直方向椭圆、圆及水平方向椭圆3种不同形态。在巷道底板中布置注浆锚索(杆)可以形成一定厚度的挤密加固拱结构,能有效阻止巷道底板拱结构向深部发育,从而改善巷道底板稳定性;以陕西彬长矿区某矿回风大巷底板修复为例,运用上述理论对该巷道底板支护方案及其参数进行优化设计,现场监测结果表明,巷道底板变形控制效果良好,保证了工作面的安全高效回采。研究成果可为高地应力条件下巷道底板支护参数确定提供理论依据。

In order to solve the technical problem that the floor of the coal mine laneway is prone to floor heave and difficult to support under the condition of high ground stress, this paper, taking the invisible arch of the laneway floor as a research object, constructs the structural mechanical model of the invisible arch of the laneway floor, theoretically analyzes the mechanism of the laneway floor heave under the condition of high ground stress, puts forward the floor support scheme and the method to determine the support parameters, and verifies the support effects of this method through an engineering example.The results show that the deformation and failure of the laneway floor is essentially the process that the invisible arch structure of the floor gradually develops to the deep.The shape of the invisible arch of the floor is related to the horizontal lateral pressure and the supporting pressure of the two sides of the floor strata, which is specifically manifested in three different shapes: vertical ellipse, circle and horizontal ellipse.Placing grouting anchor cables(bolt)in the laneway floor can form a certain thickness of compaction reinforced arch structure, which can effectively prevent the development of laneway floor arch structure to the deep, so as to improve the stability of laneway floor.With the floor restoration of the return air main laneway in a mine in Binchang mining area, Shaanxi Province as an example, the floor support scheme and its parameters are optimized by using the above theory.The field monitoring results show that the laneway floor deformation control effect is good, which ensures the safe and efficient mining of the working face.The research results can provide a theoretical basis for the determination of laneway floor support parameters under high ground stress conditions.