摘要
隧道斜井进正洞处相比正常掘进具有开挖断面渐变、跨度大、结构复杂等特点,且过程中初支结构需要多次的应力转化,施工难度大、安全风险高,易出现冒顶、掉块等问题。西渝高铁樊哙隧道斜井进正洞挑顶施工,对过渡段进行小导管注浆和异形钢拱架加强,先纵向、横向开挖导洞再纵向分三台阶开挖正洞,拱顶变形和围岩水平收敛符合控制要求。挑顶方案有效的控制了交叉段的变形,总体效益良好,施工方案科学合理。
Compared with conventional tunnel excavation,the intersection of an inclined shaft and the main tunnel is characterized by a gradually varying excavation cross-section,large spans,and complex structural configurations.In addition,the initial support undergoes multiple stress redistributions during construction,resulting in high difficulty and significant safety risks such as roof collapse and block failures.Focusing on the inclined shaft construction in the Fankuai Tunnel along the Xi'an-Chongqing High-Speed Railway,this study adopts roof-jacking construction methods.These include small-diameter pipe grouting and the reinforcement of irregular steel arches in the transition section,followed by pilot tunnel excavation in both longitudinal and transverse directions,and ultimately a three-step longitudinal excavation of the main tunnel.Monitoring data indicate that the vault deformation and the horizontal convergence of surrounding rock remain within acceptable limits.This roof-jacking approach effectively controls deformation in the intersection zone,yielding favorable overall performance and a scientifically sound construction scheme.
作者
王文昭
WANG Wenzhao(China Railway 20th Bureau Group 4th Engineering Co.,Ltd.,Qingdao 266000,China)
出处
《国防交通工程与技术》
2025年第1期57-60,共4页
Traffic Engineering and Technology for National Defence
关键词
斜井
正洞
挑顶施工
过渡段施工
异形钢拱架
inclined shaft
main tunnel
roof-jacking construction
transition section construction
irregular steel arch frame
