摘要
结合连拱隧道工程实践,对隧道施工中先行洞室支护体系应力进行相关监测,分析不同开挖工序下应力变化规律。研究结果表明:先行洞室上台阶及仰拱开挖引起了支护应力较大变化及重分布,为支护稳定的控制点;隧道开挖对支护应力的纵向影响距离大致为隧道跨度的2倍,约为20～25 m;开挖效应消失后,左右拱圈45°处应力的时间效应较其它位置要明显;封闭支护结构是改善结构受力的有效途径,应及时施作仰拱和形成封闭环。该研究结论可为类似条件下连拱隧道设计施工和现场监测提供借鉴与参考。
With a double-arch tunnel project as the background,stress monitoring of the support system was carried out and the stress variation during different excavation stages was analyzed in detail with some conclusions drawn.Since the excavation of upper-bench and invert of the headings caused great changes in support stresses,they were the main stages to control the support stability.The longitudinal influence of tunnel excavation was 20 to 25 m,about two times of the excavation span.After the excavation effect disappeared,time effect on the 45°position of the arch was more obvious than on other positions.Closing up the lining ring can improve its performance.Therefore,the invert and the lining ring should be closed up in time.The experience and conclusions presented herein can be referred to in the design,construction and monitoring of similar tunnels.
出处
《现代隧道技术》
EI
北大核心
2011年第1期33-41,共9页
Modern Tunnelling Technology
关键词
连拱隧道
支护体系
现场监测
力学性态
Double-arch tunnel
Support system
In-situ monitoring
Performance
