大直径盾构隧道下穿既有高铁线变形控制技术研究

Research on Deformation Control Technology of Large Diameter Shield Tunneling Under Existing High-Speed Railway Line

盾构隧道施工会不可避免地对周围土体产生扰动,当新建盾构穿越既有高铁线时,保证高铁运营的安全性是施工过程中的关键性问题之一。以苏州桐泾路北延工程盾构下穿沪宁城际高铁为例,通过建立三维数值模型分析大直径盾构隧道施工对高铁桩基变形的影响,结合现场监测数据实现快速预测施工变形,并对盾构下穿既有高铁线变形控制技术进行研究,提出洞内外复合隔离加固措施的同时,还应加强对盾构掘进、同步注浆与二次注浆参数的控制。

Shield tunnel construction will inevitably disturb the surrounding soil,and when a new shield crosses an existing high-speed railway line,ensuring the safety of high-speed railway operation is one of the key issues in the construction process.Taking the shield crossing of Shanghai-Nanjing intercity high-speed railway in Suzhou Tongjing Road North Extension Project as an example,we analyze the impact of large-diameter shield tunnel construction on the deformation of high-speed railway pile foundation by establishing a three-dimensional numerical model,and realize rapid prediction of construction deformation by combining with field monitoring data.In addition,we study the deformation control technology of shield crossing existing high-speed railway lines,and propose that the control of shield tunneling,synchronous grouting and secondary grouting parameters should be strengthened while taking composite isolation and reinforcement measures inside and outside the tunnel.