切顶自成巷约束混凝土支柱试验研究与应用

Experimental study and application of confined concrete column for automatically roofcutting formed roadway

切顶自成巷技术通过顶板定向切缝与矿压做功,使采空区顶板垮落自动形成巷道(简称自成巷)。为保证切顶自成巷稳定,需要一种高强、高刚的支护结构控制顶板变形并抵抗采空区垮落岩体。轻型约束混凝土(简称CLC)结构是一种在约束材料中充填轻骨料混凝土的复合结构,具有高承载、高刚度、轻自重的特性。为明确CLC支护结构的承载性能,满足支顶护帮控制要求,开展不同截面形状、偏心距下CLC支护结构与常用型钢支护的室内和数值试验,分析各类试件的变形模式和承载性能,研究截面参数、偏心距对支柱承载性能的影响机制。结合上述试验结果,在特大型矿井柠条塔煤矿开展CLC支柱选型设计与现场应用,取得良好的自成巷围岩控制效果。

By deploying directional roofcutting and the mininginduced pressure,selfcaving of the roof above the goaf could form the roadway automatically,which is the socalled automatically roofcutting formed roadway technology.To ensure the stability of the formed roadway,a supporting structure with high strength and high rigidity is necessary to control the roof deformation and resist the rock collapse from the goaf.Confined light concrete(CLC)structure is a composite structure manufactured by filling lightweight aggregate concrete into the confined material,which has characteristics such as high bearing capacity,high rigidity,and light selfweight.To understand the bearing behaviour of CLC supporting structure and to meet the controlling requirements of roof and rib support,this study carried out the lab and numerical tests on CLC supporting structure and normal structural steel support considering different section shapes and eccentricities.The deformation mode and bearing capacity of various specimens were analyzed,and the influence mechanism of crosssectional parameters and eccentricities on the bearing capacity of supporting structures were also discussed.Based on the above testing results,CLC supporting columns were designed and applied in an extremely large coal mine:Ningtiaota Coal Mine,and favorable controlling effects of the automatically formed roadway were achieved.