隧道开挖对邻近桩基影响的两阶段分析方法

隧道开挖过程中必然引起周围土体的侧向移动，从而使邻近桩基产生水平变形和附加弯矩。目前有限元数值模拟法建模与计算过程较为繁琐，为了解决隧道开挖下桩土相互作用问题，基于Winkler地基模型，采用两阶段分析方法，建立了隧道开挖条件下被动桩受力分析模型，推导出桩土相互作用控制方程，并基于有限差分思想给出近似解的形式。最后结合工程实例表明，该近似解与现场监测数据较为吻合，能够有效地分析隧道开挖对邻近桩基的影响。

Two-stage Analysis Method for the Influence of Tunnel Excavation on Adjacent Pile Foundations

The excavation of the tunnel will inevitably cause the lateral movement of the surrounding soil, which will cause horizontal deformation and additional bending moments of adjacent pile foundations. At present, the modeling and calculation process of finite element numerical simulation is relatively tedious. In order to solve the problem of pile-soil interaction under tunnel excavation, based on Winkler foundation model, a two-stage analysis method was used to establish a passive pile stress analysis under tunnel excavation conditions. The governing equation of pile-soil interaction was derived and the approximate solution is given based on the finite difference idea. Finally, the results combined with the engineering example shows that the approximate solution is in good agreement with the field monitoring data and can effectively analyze the influence of tunnel excavation on adjacent pile foundations.