暗挖隧道SRG拱架节点抗弯性能及参数影响机制研究  

Bending Performance and Parameter Influencing Mechanism of Spatial Reticulated Grid Joint Components in Mined Tunnel

作　　者：宋远 黄明利[2] 张旭东[3] 李然 SONG Yuan;HUANG Ming-li;ZHANG Xu-dong;LI Ran(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 23200l,Anhui,China;Key Laboratory for Urban Underground Engineering of the Education Ministry,Beijing Jiaotong University,Beijing 100044,China;China Railway 1lth Bureau Group Co.Ltd.,Wuhan 430061,Hubei,China;China Tiesiju Civil Engineering Group Co.Ltd.,Hefei 230023,Anhui,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001 [2]北京交通大学城市地下工程教育部重点实验室,北京100044 [3]中铁十一局集团有限公司,湖北武汉430061 [4]中铁四局集团有限公司,安徽合肥230023

出　　处：《中国公路学报》2024年第4期286-296,共11页China Journal of Highway and Transport

基　　金：安徽理工大学引进人才科研启动基金项目(2022yjrc85);国家重点研发计划项目(2018YFC0808705);国家自然科学基金项目(51878037);安徽省博士后科研活动项目(2022B642)。

摘　　要：为解决软弱围岩暗挖隧道变形控制技术难题,满足高承载力和高稳定性的支护需求,研发出了一种新型装配式空间网架(SRG)支护结构。节点作为整环结构受力及变形的薄弱部位,其力学特性对准确评价整体承载性能至关重要,为了探明不同节点形式的性能差异,针对SRG拱架开展了螺栓端板节点、组合套筒节点和无节点构件的纯弯室内足尺试验和数值模拟,对比分析了各构件的变形过程和破坏形态,建立了弯矩-曲率函数方程,定量评价了节点抗弯刚度及承载力。系统分析了端板厚度、套筒长度、钢管壁厚等参数对螺栓端板节点、组合套筒节点及无节点试件力学性能的影响规律,明确了节点参数影响机制,提出了拱架节点参数合理取值及设计建议。此外,依托广州地铁暗挖隧道工程开展了SRG拱架的现场应用。结果表明:螺栓端板节点具有较高的韧性和承载能力,在加载过程中节点力系传递明确,受力变形稳定,可作为SRG拱架优选的节点类型;组合套筒节点具有较好的延展性和后期变形能力,在加载过程中组合套筒受力状态良好,未产生明显变形;端板厚度增加,试件的屈服承载力增幅明显,厚度由15 mm增至25 mm,承载力相应提高了14.6%;采用“上3下4”螺栓布置方式的节点构件,其屈服承载力与“上5下6”螺栓布置方式仅相差3.1%;相较于格栅拱架支护,SRG拱架的整体性有所增强,围岩控制效果得到明显改善,拱顶沉降值和周边收敛分别减少了31.6%和31.4%,研究结果可为今后类似工程的设计与施工提供借鉴。To solve the technical problems concerning deformation control of tunnels surrounded by soft and weak rock, as well as meet the support requirements of high bearing capacity and high stability, a new type of prefabricated spatial reticulated grid(SRG) support structure was developed. As the weak part of the whole ring structure, the mechanical properties of the joints are crucial to the accurate evaluation of the overall bearing performance. To determine the difference in performance of different joint types, indoor full-scale tests and numerical simulations of pure bending of bolted endplate joint, combined sleeve joint, and jointless components were carried out for SRG arches. The deformation process and failure modes of each component were compared and analyzed, the bending moment-curvature function equation was established, and the bending stiffness and bearing capacity of the joints were evaluated quantitatively. The influence of endplate thickness, sleeve length, steel tube wall thickness, and other parameters on the mechanical properties of bolted endplate joint, combined sleeve joint, and jointless components were comprehensively analyzed, the influence mechanism of joint parameters was clarified, and reasonable parameters and design suggestions for arch joints were proposed. In addition, the field application of SRG arches was investigated considering on the Guangzhou Metro underground excavation tunnel project. The results show that the bolted endplate joint has high toughness and bearing capacity, the clear transmission of the joint force system during the loading process, stable deformation, and can be used as the preferred joint type for SRG arches. The combined sleeve joint has good ductility and post-deformation capability, and the combined sleeve is in good condition without significant deformation. The yield load capacity of the bolted endplate joint component increases significantly when the thickness of the endplate increases from 15 to 25 mm, resulting in a corresponding increase of 14.6%. The

关 键 词：隧道工程 空间网架 模型试验 抗弯性能 螺栓端板节点 组合套筒节点 

分 类 号：U455[建筑科学—桥梁与隧道工程]