煤巷复合顶板变形破坏规律及稳定性研究

Study on Deformation and Failure Rules and Stability of Composite Roof of Coal Roadway

根据煤巷复合顶板变形破坏规律,对复合顶板进行稳定性分析,结果表明:①在结构承载调整阶段,巷道开挖后,会产生少量弹性变形,但不会立刻发生失稳破坏;②结构刚度软化的实质,是顶板中的软弱夹层受围岩应力作用,产生拉伸或压缩裂缝,并持续扩展;③在应力调整阶段,当纵向均布荷载超过临界值后,顶板岩层将会产生溃屈破坏;④在巷道支护设计中,采取有效措施,增强巷道整体刚度,就能保证安全。

According to the deformation and failure rules of the composite roof of a coal roadway,the stability of the composite roof was analyzed.The results show that:firstly,in the stage of structural load adjustment,a small amount of elastic deformation of the surrounding rock will occur after the roadway being excavated,but the instability and failure will not occur at once;secondly,the essence of structural stiffness softening is that the weak interlayer in the roof produces cracks by surrounding rock stress,and the cracks continue to expand;thirdly,in the stage of stress adjustment,the roof strata will bring about collapsing destruction when the longitudinal uniformly distributed load exceeds the critical value;fourthly,in the roadway support design,if the effective measures being used to enhance the overall stiffness of the roadway,the safety can be ensured.