盾构隧道开挖对邻近被动桩基稳定性的影响研究  

Research on the Influence of Shield Tunnel Excavation on Stability of the Adjacent Passive Pile Foundations

作　　者：刘宇 王梦林 孙森 周亚东 Liu Yu;Wang Menglin;Sun Sen;Zhou Yadong(Eighth Engineering Co.,Ltd.,CCCC First Highway Engineering Co.,Ltd.,Tianjin 300170,China;School of Civil Engineering,Tianjin Chengjian University,Tianjin 300384,China)

机构地区：[1]中交一公局第八工程有限公司,天津300170 [2]天津城建大学土木工程学院,天津300384

出　　处：《市政技术》2025年第3期202-208,214,共8页Journal of Municipal Technology

基　　金：天津市自然科学基金重点资助项目(18JCZDJC10010)。

摘　　要：盾构隧道开挖对邻近既有建筑物的被动桩基稳定性具有显著影响,现有的桩基侧向变形计算方法通常忽略桩身轴力、土体分层及边界条件的影响。因此,综合考虑上述影响,采用桩身离散分段方法,建立了隧道开挖条件下被动桩基的应力应变分析模型。采用Loganathan公式计算隧道开挖引起的桩周土体自由水平位移,进而计算桩基的附加水平应力,并利用弹性地基梁方法实现了层状地基和不同边界条件组合情形下被动桩基桩身水平位移和内力的求解。采用既有研究的试验值和解析解验证了所提模型的准确性。通过算例分析,进一步探讨了桩身轴力、桩顶和桩端边界条件以及土体分层对被动桩基稳定性的影响。研究结果表明:桩身变形和内力的最大值通常出现在隧道轴线附近,被动桩基的桩身变形和内力随着桩顶荷载的增大而增大,桩顶及桩端边界条件是被动桩基稳定性的重要影响因素,将层状地基简化为均质土层会导致对桩基稳定性的评估产生明显误差。The excavation of shield tunnels has a significant impact on the passive pile foundation stability of adjacent existing buildings.Existing methods for calculating the lateral deformation of pile foundations often overlook critical factors such as the axial force of the pile body,foundation layering,and boundary conditions.Therefore,considering the above factors,a stress-strain analysis model for passive pile foundations under tunnel excavation conditions is established using the discrete segmentation method for the pile body.The Loganathan formula is used to calculate the free horizontal displacement of the soil around the pile caused by tunnel excavation,and the additional horizontal stress of the pile foundation is calculated.The elastic foundation beam method is used to solve the horizontal displacement and internal force of the passive pile foundation under layered foundation and different boundary condition combinations.The accuracy of the proposed model is validated using experimental values and analytical solutions from existing research.Through numerical analysis,the influence of axial force,boundary conditions at the pile top and end,and soil layering on the stability of passive pile foundations was further explored.The research results indicate that the maximum deformation and internal force of the pile body usually occur near the tunnel axis.Both the deformation and internal forces of the passive pile foundation increase with higher pile top load.Additionally,the boundary conditions at the pile end and top are identified as critical factors affecting the stability of the passive pile foundation.Simplifying the layered foundation to a homogeneous soil layer will lead to significant errors in the evaluation of the stability of the pile foundation.

关 键 词：盾构隧道 被动桩基 弹性地基梁 附加水平应力 层状地基 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]