紫坪埔隧道小净距段施工方案模型试验研究

为节约工程造价,董家山隧道汶川端设计为渐变小净距隧道与整幅修建的泯江大桥相接。该端隧道洞口段左、右线间距较小,围岩较差。为保证隧道的安全施工,利用模型试验对洞口小净距段岩墙的加固措施、开挖方式及支护体系等施工方案进行了研究,提出了该段合理的施工方法和岩墙加固措施的建议,为董家山隧道小净距段的顺利施工提供指导。

Experimental study on the construction options for the section of Zipingpu twin - bored tunnels in close proximity

For the purpose of saving construction cost,Wenchuan portal section of Dongjiashan tunnel is so designed that twin tunnels in close proximity are connected with Minjiang bridge.On this portal section the spacing between right and left lines is small and the wall rock between them is weak.For the safety of tunnel construction,model test was applied to study the construction options such as rock-reinforcing measures,excavation methods and support systems for the section of tunoels in close proximity.The results of study helped the smooth completion of Dongjiashan tunnel.