摘要
为解决城市软弱围岩浅埋暗挖隧道在施工过程中容易出现支护不及时、支护强度不足的问题,采用数值模拟和室内模型试验相结合的方法,对空间网架锚喷支护作用原理、承载力学特性展开研究,提出及时形成强力支护、实时承担围岩荷载的“及时高强支护”理念,创新性地设计出装配式空间网架支护结构及节点形式,建立高强度空间网架锚喷支护体系。结果表明:1)采用高强度的空间网架结构作为隧道初期支护,有利于改善应力应变状态,提高结构整体承载性能;2)在压弯荷载作用下,上主肢钢管受压率先进入屈服破坏,螺栓端板节点构件较无节点构件表现出更高的承载力及抗弯刚度;3)关于变形破坏模式,螺栓端板节点混凝土构件表现为跨中区域竖向裂纹发展破坏,无节点混凝土构件呈现出大范围的裂纹扩展规律;4)无节点混凝土构件具有较好的可变形能力,其极限承载力约为螺栓端板节点混凝土构件的1.2倍,而螺栓端板节点混凝土构件的抗弯刚度较高,对变形的控制效果更好。
To address the untimely and inadequate support strengths in shallowly-buried mined tunnels in soft surrounding rocks in urban settings,numerical simulation and indoor model tests are introduced to investigate the principle of a spatial reticulated grid bolt-shotcrete support and the mechanical characteristics of bearing capacity.Simultaneously,the concept of timely high-strength support is proposed to form a strong support in a timely manner that bears the load of surrounding rocks in real time.Moreover,the prefabricated spatial reticulated grid support structure and joint type are designed innovatively,and a high-strength spatial reticulated grid bolt-shotcrete support system is established.The results reveal the following:(1)The use of a high-strength spatial reticulated grid as the primary support of the tunnel is convenient for improving the stress state and the overall bearing capacity of the structure.(2)When subjected to compression and bending loads,the upper main leg steel tube first experiences yield failure,and the bolted endplate joint component demonstrates higher bearing capacity and bending stiffness than the jointless component.(3)In terms of failure modes,the concrete component with the bolted endplate joints shows a vertical crack development in the midspan region,whereas the concrete component without joints shows a larger range of crack development.(4)The concrete component without joints has good deformability,and its ultimate bearing capacity is 1.2 times that of the concrete component with the bolted endplate joints.However,the bending stiffness of the concrete components with the bolted endplate joints is higher,and the deformation control effect is better.
作者
宋远
黄明利
张旭东
李然
SONG Yuan;HUANG Mingli;ZHANG Xudong;LI Ran(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232001,Anhui,China;Key Laboratory for Urban Underground Engineering of the Ministry of Education,Beijing Jiaotong University,Beijing 100044,China;China Railway 11th Bureau Group Corporation Limited,Wuhan 430061,Hubei,China;China Tiesiju Civil Engineering Group Co.,Ltd.,Hefei 230023,Anhui,China)
出处
《隧道建设（中英文）》
CSCD
北大核心
2023年第2期273-284,共12页
Tunnel Construction
基金
安徽理工大学引进人才科研启动基金(2022yjrc85)
国家重点研发计划课题(2018YFC0808705)
安徽省博士后研究人员科研活动经费资助项目(2022B642)。
关键词
暗挖隧道
装配式空间网架
及时高强支护
数值模拟
室内足尺试验
mined tunnel
prefabricated spatial reticulated grid
timely high-strength support
numerical simulation
indoor full-scale test
作者简介
第一作者:宋远(1991-),男,安徽安庆人,2022年毕业于北京交通大学,土木工程专业,博士,讲师,主要从事隧道与地下工程方面的教学与科研工作。E-mail:18115036@bjtu.edu.cn。
