A newly-built overpass crosses over repeatedly the adjacent shield-tunnel, and the bridge pile foundation is very close to the shield-tunnel, which falls into approaching construction. During the construction of the pile foundation, some factors like drilling disturbance and construction load result in the displacement and deformation of strata, causing displacement and deformation of the tunnel structure. By numerical simulation, the paper analyzes the internal force and displacement of the tunnel structure due to bridge pile construction, optimizes bridge design and construction plan and minimizes the influence and risks. The simulation results obtained by Midas/GTS show that the maximum settlement deformation of arch crown and radial convergent deformation are within the specified limits and comply with the field monitoring data.%某新建立交桥多次跨越地铁盾构区间隧道,其桩基基础工程离盾构隧道结构较近,属于近接施工.在新建立交桩基施工过程中,由于钻孔扰动、施工荷载等因素会引起地层产生移动和变形,导致附存于地层中的区间隧道结构随之发生移动和变形.通过数值模拟,分析桥梁桩基施工对隧道结构的内力及位移影响,进一步对桥梁设计及施工方案进行优化,以减小近接施工的影响,规避一定量风险.通过数值模拟软件Midas/GTS计算得出的管片位移、盾构隧道拱顶最大沉降变形与径向收敛变形均未超过控制标准,其模拟计算结果与现场监测数据基本相符.
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