盾构隧道近距离穿越既有线高架桥施工技术研究

Study on construction technology of shield tunnel crossing existing line viaduct in short distance

地铁隧道穿越既有运营线路高架桥已经是常态,地铁盾构隧道穿越既有运营高架桥梁时,确保新建地铁隧道工程自身结构安全,又能保证既有线结构的运营安全,是必须解决的问题。以某地铁盾构区间隧道下穿既有线区间高架桥为工程背景,论述了注浆隔离加固、桥梁支顶及盾构掘进施工的技术要点。监测数据表明该方法可行,能够有效保障穿越期间高架桥的整体稳定性,并为今后城市地铁下穿既有线高架桥施工提供经验参考。

It is normal for the subway tunnel to cross the viaduct of the existing operating line.When the subway shield tunnel crosses the existing operating viaduct,it is a problem that should be solved to ensure the structural safety of the new subway tunnel project and the operation safety of the existing line structure.In this paper,the technical points of grouting isolation reinforcement,bridge roof support and shield tunneling construction is discussed based on the background of a subway shield tunnel under the existing line section viaduct.The monitoring data show that this method is feasible and can effectively guarantee the overall stability of the viaduct,and provide experience reference for the construction of the viaduct under the existing line of urban subway in the future.