明挖法隧道上跨既有轨道交通区间隧道设计方案及保护措施研究

Design Scheme and Protection Measures for Cut & Cover Tunnel over Crossing Existing Rail Transit Running Tunnel

城市道路隧道采用明挖法上跨穿越已建轨道交通区间隧道,会使区间结构产生相应的变形和内力,影响轨道交通区间的正常运营甚至结构安全。结合苏州元和塘西隧道上跨轨道交通4号线盾构区间工程实例,基于基坑工程"时空效应"原理,采用分坑施工、加大净距、地基加固、设置桩基础等保护措施,并通过预制钢筋笼与非原位试验演练等方法加快施工速度。计算结果表明,设计方案及保护措施合理有效,可供类似工程参考。

The urban road tunnel over crossing the existing rail transit running tunnel by cut&cover method will result in the deformation and internal force of the running tunnel,which will influence the normal operation and even the structural safety of the running tunnel.In the construction of the West Yuanhe River Tunnel in Suzhou,which over crosses the shield running tunnel of Suzhou Rail Transit Line 4,the excavation design was based on the"space-time effect"principle and the protective measures such as pit division construction,increasing clear distance,ground improvement and pile foundation were adopted.Meanwhile,the construction speed was accelerated by the prefabricated reinforcement cage and non-in-situ test.The calculation results show that thei design scheme and protection measures are reasonable and effective,which can be used as a reference for similar projects.