加固顶板和两帮控制回采巷道底臌研究

回采巷道围岩是由顶板、两帮和底板共同组成的复合结构体,各部位的岩体强度、应力状态及变形破坏等特性方面的差异显著,尤其受采动影响后,巷道围岩各部位变形发展不均匀性显著,往往造成巷道围岩产生结构性失稳破坏。为提高巷道围岩的结构稳定性,通过理论分析和数值模拟分析了提高顶板和两帮强度对底板岩层稳定性的影响。研究结果表明:加固顶板减小了顶板挠曲位移量,同时可以促使围岩应力向深部围岩转移,降低了底板岩层的应力集中程度,有利于控制底板变形;加固两帮可以提高巷道两帮围岩强度,促使应力向两帮转移,有利于减小发生底鼓的底板岩层宽度和两帮移近量,从而减小底板的挠曲效应和压曲效应。分析结果还表明,加强两帮对于减小底鼓量的效果更为明显。在上述分析的基础上,进行了加固顶板和两帮控制巷道底鼓支护技术的现场工业性试验,试验结果表明加固顶板和两帮可有效地控制巷道底鼓。

Mechanism of reinforcing roof and sides for floor heave control of roadway

The surrounding rock of roadway is a composite structure consisted of roof, sides and floor. Rock mass strength, stress state and deformation failure characteristic of various parts of the surrounding rock are significant differences. Particularly, the various parts deformation of surrounding rock of roadway shows Non-uniform development. This always caused by a structural instability failure of surrounding rock. In order to improve the structural stability of surrounding rock, through the theoretic analysis and numerical simulation, the stability of floor affection by roof and sides is discussed. The results showed that： reinforced roof can decrease its flexure displacement and promote surrounding rock stress transfer to the deep rock, reducing the floor stress concentration is conducive to floor heave control;reinforced sides help to improve its strength, impel stress transfer to sides, contribute to reduce the rib sides convergence and width of floor occurred vertical displacement, thereby reducing flexural effect and press effect of floor. The results also show that reinforeing sides is more effective than roof. This theory is applied to the technology of control floor heave by reinforcing roof and sides. Field testing and monitoring shows that the large-scale deformation and floor heave are successfully controlled.