基于煤巷两帮基础刚度效应的控帮护巷支护原理

煤层巷道两帮煤体相对顶底板岩层强度低、可变形性强,两帮煤体大变形对巷道围岩整体稳定性有着极其重要的影响。基于煤巷两帮煤体严重变形的工程实际,考虑巷道两帮煤岩体的可变形性,建立了由Winkler可变形基础支承的顶板悬梁力学模型,分析并揭示了顶板的弯矩和挠度分布特征及规律,提出了基于煤巷基础刚度效应的"控帮护巷"支护原理:通过加强两帮支护提高锚固煤体的基础刚度,控帮支护的直接控制两帮煤体的变形和破坏,并进一步通过基础刚度效应改善整个巷道围岩的应力状态,抑制顶底板变形破坏,提高围岩承载能力和稳定性。通过数值模拟分析与现场工程试验,对基础刚度效应和"控帮护巷"原理进行了分析和验证。研究表明:在两帮垂直集中应力作用下,巷帮煤体压缩变形明显,顶板岩层随基础变形而弯曲下沉,两帮基础刚度对顶板变形量影响显著,是顶板变形的关键影响因素;在顶板支护相同的条件下,加强两帮支护不仅使掘进和采动影响期间的两帮的塑性破坏范围和移近量显著缩小,还有效地控制了顶底板的变形破坏情况,是巷道围岩整体稳定性控制的有效途径。研究工作深化了煤巷围岩控制中对巷帮支护重要性的认识,揭示了控帮护巷的支护机理。

Rib control support principle based on the foundation rigidity of coal mine roadways

Comparing to the roof and floor,the two ribs of coal mine roadways are relatively weaker and have more deformability.The large deformation of the coal mass in the ribs have significant effect on the roadway stability.Based on the practical case of severely deformed ribs and by considering its deformability,an analytical model of roof beam with Winkler foundation is built.Hereby the characteristics of bending moment and reflection have been studied.The foundation rigidity of coal mine roadway is revealed and the rib control support principle is proposed.By employing reinforcement in the ribs,the foundation rigidity of the ribs will increase,and the deformation and failure of the ribs will directly controlled by the reinforcement.The stability of roof and floor is reinforced via the foundation rigidity effect.The foundation rigidity and the rib control support principle of coal mine roadway are analyzed and validated by means of numerical simulation and field tests.The results show that under the effect of the vertical concentrated stress over ribs,the coal mass is notably compressed and the roof strata bend and sag along with it.The foundation rigidity has great effect on roof deformation which makes it the key influencing factor.Under the conditions of identical roof support,the reinforcement in the ribs will not only reduce the convergence and failure extent of the ribs during roadway development and retreat mining,but also effective control the deformation and failure of the roof and the floor,which makes it an effective method to improve the roadway stability.This study has improved the understanding of the importance of rib support in roadway ground control,and revealed the support mechanism of rib control.