盾构切割素混凝土过暗挖隧道下穿既有线施工技术

通过工程实践介绍了成都地铁4号线土压平衡盾构机切割二衬素混凝土过暗挖隧道下穿既有运营线的施工技术,明确了该技术的适用范围,详细介绍了过暗挖隧道的开挖及二衬施工、端头加固、盾构掘进、注浆的施工技术,保证了既有运营线路的安全,对今后盾构过暗挖隧道穿越既有线施工具有很好的参考和应用价值。暗挖隧道的结构形式不同于以往的盾构空推过暗挖隧道的结构形式,值得借鉴。

Construction Technology for Tunnels Under-crossing the Existing Tunnel Line by Cutting the Plain Concrete with Shield Machine

Based on the example of the construction technology of Chengdu metro line 4 under-crossing the existing operat-ing line by cutting the second lining concrete with earth pressure balance shield machine,the paper makes clear the appli-cation scope of the technology and introduces mined tunnel excavation and second lining construction technology,end rein-forcement technology,the construction of shield tunneling,and the grouting technology,which ensure the safety of the ex-isting operating line.It is of the application value to shield mined tunnels crossing the existing lines in the future which can be taken as reference.The structure of mined tunnel is different from the previous shield empty dug tunnels,which is worth considering.