复合顶板巷道组合三铰拱断裂形成的力学机理

Mechanical Mechanism Formed by Combined Three-hinged Arch Fractured in Composited Roof

为了揭示软弱夹层引起顶板分阶段破坏的力学机理,采用数值模拟的方法揭示含软弱夹层(煤线)的复合顶板巷道变形和破断规律,通过建立巷道复合顶板破断结构模型,确定复合顶板断裂的力学条件,并通过现场探测进行验证。研究表明:复合顶板中软弱夹层的破坏是致使顶板变形和破断的主要因素,复合顶板变形破坏过程大致可分为"嵌固梁形成→叠加组合梁形成→组合三铰拱形成"3个阶段;当复合顶板各岩层的屈服跨距小于等于巷道实际跨度时,复合顶板将破断形成组合三铰拱结构。

For revealing mechanical mechanism of roof staging damage caused by weak intedayers, numerical simulation is adopted to reveal the deformation and failure laws of composite roof which contains the weak interlayers （ coal lines）. Failure structure model of composite roof is established to determine mechanical conditions of composited roof, and it is proved by field test. The results show that the damaged weak interlayer is the key element for roof deformation and fracture; the process of the composite roof deformation and fracture can be broken down into three stages that fixed end beam, laminated composite beams, combined three - hinged arch; the composite roof can be damaged and turned into combined three - hinged arch when the yield span of each rock is less than actural span of composite roof.