运营公路隧道局部换拱效果及其工程影响

Effect and Influence of Arch Exchange in Operating Highway Tunnel

通过对运营公路隧道换拱工程试验段衬砌荷载和温度的现场监测,并将之与新建隧道衬砌荷载分布规律进行对比,评价换拱工程中新施作衬砌的承载性能。通过采用数值计算分析的手段,对换拱过程临近结构附加影响进行研究。结果表明:换拱工程与新建隧道工程衬砌荷载分别在荷载曲线形态和达到峰值的时间这2个方面存在明显差异;结合衬砌温度变化规律,揭示了换拱工程的新施作衬砌基本不发挥承载作用,现场监测所得荷载主要是由温度应力引起的;分析换拱过程中,邻近结构在卸荷作用下产生一定的附加沉降和附加应力。综合换拱工程衬砌承载效果及对临近结构的影响,提出了在运营隧道衬砌病害处理过程中,宜优先采用非破坏性防护措施,慎用局部换拱方案的工程建议。

In this paper, the lining load and temperature of tunnel arch exchange test section of operating highway tunnelare monitored, and the monitoring results are compared with the load distribution law of newly-built tunnel lining, so asto evaluate the bearing capacity of newly-built tunnel lining during tunnel arch exchange. The additional load onadjacent structure induced by tunnel arch exchange is studied by using numerical calculation analysis method. Theanalytical results show that： 1） There are significant differences between tunnel arch exchange project and newly-builttunnel construction in terms of load curve form and peak time. 2） According to the lining temperature variation law, it isrevealed that the newly-built tunnel lining does not bear the basic rock load, and the load monitored is mainly inducedby temperature stress. 3） Through The analysis of tunnel arch exchange, additional deformation and stress induced byload effect can be measured on adjacent structure. The non-destructive protection measures should be adoptedpreferentially and the local tunnel arch exchange scheme should be seriously considered when carrying out tunnel diseasetreatment.