连拱隧道无导洞后扩挖法设计参数及其影响性分析
Design parameters and influencing analysis of post-expansion excavation method without pilot tunnel in continuous arch tunnel
刘晓 1张奎红 1周飞 2陈跃 1华成龙1
作者信息
- 1. 中交基础设施养护集团工程有限公司,北京 100102
- 2. 长安大学 公路学院,陕西 西安 710064
- 折叠
摘要
为了研究双连拱隧道采用无导洞后扩挖法施工时的设计参数取值及其对隧道稳定性的影响,采用数值模拟方法分析连拱隧道主洞错距、台阶长度、中隔墙厚度以及二衬施作时机4 个参数对隧道受力与变形的影响规律,并与现场监测结果进行对比验证.研究结果表明:主洞错距达到75m时,既能保证先行洞隧道的变形稳定,又能缩短工期;隧道先行洞台阶长度可以按单洞隧道取值,后行洞台阶长度建议控制在5～10m为宜;考虑施工扰动的影响,隧道中隔墙厚度在1.4～1.6 m范围内取值较为合理;先行洞二衬在后行洞掌子面前保持35m以上距离施工有利于隧道稳定性的控制.研究结果可为隧道工程施工提供参考.
Abstract
In order to study the design parameters and their influence on the stability of double-arch tunnel during the con-struction by the post-expansion excavation method without pilot tunnel,the numerical simulation method was used to analyze the influence of four parameters on the stress and deformation of the continuous arch tunnel,including the staggered distance of main tunnel,the length of steps,the thickness of middle partition wall,and the application time of second lining,and the re-sults were compared with the on-site monitoring results.The results show that when the staggered distance of main tunnel rea-ches 75 m,it can not only ensure the deformation stability of the first tunnel,but also shorten the construction period.The length of steps of the first tunnel can be taken according to the value of single tunnel,and the length of steps of the rear tunnel is recommended to be controlled as 5～10 m.Considering the influence of construction disturbance,the thickness of middle partition wall in the tunnel is more reasonable in the range of 1.4～1.6 m.The second lining of the first tunnel should be more than 35 m distance in front of the tunnel face of rear tunnel,which is conducive to the control of tunnel stability.The re-search results can provide a reference for the construction of tunnel projects.
关键词
双连拱隧道/无导洞法施工/设计参数Key words
double-arch tunnel/construction method without pilot tunnel/design parameter引用本文复制引用
出版年
2024
NETL
NSTL
万方数据