Research Center of Geotechnical and Structural Engineering, Shandong University
State Key Laboratory for Tunnel Engineering, China University of Mining andTechnology-Beijing

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 roof-cutting and the mining-induced pressure, self-caving of theroof above the goaf could form the roadway automatically, which is the so-called automatically roof-cut-ting formed roadway technology. To ensure the stability of the formed roadway, a supporting structurewith high strength and high rigidity is necessary to control the roof deformation and resist the rock col-lapse from the goaf. Confined light concrete (CLC) structure is a composite structure manufactured byfilling lightweight aggregate concrete into the confined material, which has characteristics such as highbearing capacity, high rigidity, and light self-weight. To understand the bearing behaviour of CLC sup-porting structure and to meet the controlling requirements of roof and rib support, this study carried outthe lab and numerical tests on CLC supporting structure and normal structural steel support consideringdifferent section shapes and eccentricities. The deformation mode and bearing capacity of various speci-mens were analyzed, and the influence mechanism of cross-sectional parameters and eccentricities on thebearing capacity of supporting structures were also discussed. Based on the above testing results, CLCsupporting 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.

国家自然科学基金项目(42277174,52074164,42077267);山东省杰出青年科学基金项目(ZR2020JQ23);中央高校基本科研业

1 约束混凝土支护结构力学试验方案
1.1 室内试验试件参数
1.2 室内试验加载与监测方案
1.3 数值试验概况
2 试验结果分析
2.1 变形模式分析
2.2 承载性能分析
2.2.1 截面形状对CLC试件承载性能的影响
1) 线弹性阶段(OAi):
2) 弹塑性阶段(AiBi):
3) 塑性发展阶段(BiCi):
4) 破坏失效阶段(CiDi):
2.2.2 偏心距对CLC试件承载性能的影响
2.3 侧向抗弯性能分析
2.4 约束效应分析
3.5 小 结
3 约束混凝土支柱设计与现场应用
3.1 工程概况
3.2 约束混凝土支柱设计
1) 方案设计
2) 承载力分析
3.3 自成巷围岩控制效果
4 结 论