U型约束混凝土拱架力学性能及变形破坏机制试验

Study on mechanical properties and deformation mechanism of U-type confined concrete arch centering

针对深井高应力巷道支护难题,基于常规U型钢拱架设计了一种U型约束混凝土(UCC)支护系统。为明确支护系统核心构件UCC拱架的力学性能及变形破坏机制,采用自主研发的地下工程约束混凝土拱架1∶1力学试验系统,并结合数值计算方法,开展了系统的试验研究。结果表明,均压加载条件下,室内试验UCC29拱架的屈服荷载为1 230 k N,极限荷载为1 310 k N,数值模拟与室内试验结果相差仅为8.86%和12.5%,拱架整体呈现"拱顶上升,拱腿内敛,整体变瘦高"的变形形态,最大变形部位在拱腿中部至起拱点位置。拱架变形破坏机制为局部强度破坏造成拱架整体失稳。现场应用效果显示,UCC拱架具有显著的围岩控制效果,为深井高应力巷道提供了一种新型支护形式。

To overcome the problem of high stress roadway support in deep mine,a new support form—U-type confined concrete( UCC) arch centering was developed. In order to definite the mechanical properties and deformation failure mechanism of UCC arch centering,various experiments were carried out by using underground engineering confined concrete arch 1∶ 1 mechanism test system and numerical computing method. The results show that under the pressure loading conditions,the yield load of UCC29 arch is 1 230 k N and the limit load of UCC29 arch is 1 310 k N,the differences between laboratory test and numerical simulation results are only 8. 86% and 12. 5% respectively. The arch deformation form is 'vault rises,legs restrained and global variable thin',the maximum deformation region is the central legs to sprung arch position. The deformation failure mechanism of arch is global variable instability caused by local strength yield. The application shows the surrounding rock control effect of UCC arch centering is good,and the UCC arch centering is a new effective support for deep mine high stress roadway.