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轨道交通11号线盾构隧道穿越苏州河将会对防汛墙的安全造成影响。为保证盾构顺利实施,拔高影响盾构穿越的桩基,采用双跨门洞式的结构型式对防汛墙结构加固改造。在保证防汛墙安全的前提下,为隧道穿越预留了足够空间。运用有限元数值模拟方法建立计算模型,对隧道穿越前后防汛墙结构的受力和变形形态进行分析。研究结果表明,隧道穿越前底板呈连续梁变形规律,长桩桩身中部和短桩桩端呈向外侧扩张的趋势,整个结构受力性状符合门洞式刚架结构的特性。隧道穿越后,底板的变形趋势与隧道穿越前变形规律相似,最大变形位于隧道上部跨中部位,而桩基变形形态则完全不同,隧道开挖引起长桩桩身中部和短桩桩端向隧道侧的变形,长桩呈挠曲变形,桩身最大变形位于隧道拱轴线附近,短桩呈刚体变形,最大变形位于桩端。经与实测沉降数据对比,盾构的穿越对防汛墙变形的影响处于可控状态,整体防汛墙计算沉降值与实测值较为接近。
Rail Transit Line 11 Shield Tunnel crossing the Suzhou River will have an impact on the flood control wall. In order to ensure the smooth implementation of the shield, the height of the shield through the pile, the use of double-door structure of the structure of the flood control wall reinforcement transformation. Under the premise of ensuring the safety of the flood control wall, enough space is reserved for the tunnel crossing. The finite element numerical simulation method is used to establish the calculation model to analyze the forces and deformations of the flood control wall structure before and after tunnel crossing. The results show that the deformation of the continuous girder of the tunnel through the front floor is continuous. The middle part of the long pile body and the short pile tip tend to expand outward, and the mechanical behavior of the whole structure conforms to the characteristics of the portal frame structure. After the tunnel passes through, the deformation trend of the bottom plate is similar to that of the tunnel before it passes through. The maximum deformation is located in the middle of the upper part of the tunnel, while the deformation of the pile foundation is completely different. The middle part of the long pile shaft and the end- Side of the deformation, bending deformation of long pile, pile deformation is located in the tunnel near the arch axis, the short pile was rigid body deformation, the maximum deformation at the pile end. Compared with the measured settlement data, the effect of shield crossing on the deformation of the flood control wall is under control, and the settlement value of the whole flood control wall is close to the measured value.