弱胶结围岩动压影响巷道预应力钢棒支护技术研究

Research on the support technology of the prestressed steel bar for the roadway affected by dynamic pressure of the weak cementation roof rock

文中针对王坡煤矿弱胶结顶板围岩及临空多巷布置动压影响巷道的支护难题,采用现场调研、理论分析、数值模拟和井下试验的方法,分析了多次动压影响下巷道围岩的变形破坏特征,提出了巷道支护机理,据此开发了预应力钢棒支护技术并进行了井下试验。研究表明,临空巷道在掘进前已经受到采空区的影响而发生了应力变化及变形,巷道掘进后及相邻巷道掘进影响导致巷道周边塑性区连通导致围岩破坏;通过高预应力钢棒及锚索支护将弱胶结岩层加固为一个整体,抑制围岩的层间错动和裂隙发育,进而保证巷道的完整性和整体承载能力,现场试验表明,巷道变形最大为180mm,能够满足巷道的正常使用。

Aiming at the support problem of the weak cementation roof rock and the influence of the empty multi - lane arrangement dynamic pressure on the roadway in Wangpo coal mine, deformation and failure characteristics of the surrounding rock of the roadway under the influence of the dynamic pressure were analyzed using the methods of the field investigation, theoretical analysis, numerical simulation and downhole experiment, and the roadway support mechanisms were proposed, and the support technology of the prestressed steel bar was developed and the under-ground tests were carried out. Research showed that the roadway had been subjected to stress changes and deforma- tion due to the impact of the goaf before the excavation, and the plastic areas around the roadway were connected after the roadway excavation and the adjacent roadway excavation affect leading to the destruction of the surrounding rock. The weak cementite was reinforced as a whole by the high prestressed steel bars and the anchor supports suppressing interbedded fault and fissure development of surrounding rock and thus the integrity of the roadway and the overall carrying capacity were ensured. Field tests showed that roadway deformation was up to 180mm meeting the normal use of the roadway.