基于边界元法的隧道掘进对邻近基础影响研究

Influence of Tunneling on Adjacent Foundations Based on Boundary Element Method

建立边界元法研究隧道掘进施工对邻近桩基础的影响。边界元计算过程中使用圆柱单元、环形尖单元和环形不连续单元模拟桩。桩-土相互作用行为通过桩-土交界面的变形协调方程、桩受力平衡方程、桩头和承台变形协调方程以及桩头和承台的受力平衡方程进行描述。针对某隧道下穿既有桩基础工程,采用边界元和3D有限元软件Midas GTS模拟,对比分析隧道掘进引起上方桩基础的沉降,并研究了地层损失率对桩沉降的影响。研究结果为工程设计以及施工过程中隧道周边建筑保护提供参考。

A boundary element method(BEM)was established to study the influence of tunnel excavation on adjacent pile foundations.Cylindrical element,annular tip element and annular discontinuous element were used to simulate piles in the process of BEM calculation.The behavior of pile-soil interaction was described by the deformation compatibility equation of pile-soil interface,the force balance equation of pile,the deformation compatibility equation of pile head and cap,and the force balance equation of pile head and cap.Aiming at the existing pile foundation project under a tunnel,the settlement of pile foundation caused by tunnel excavation was simulated,compared and analyzed by boundary element method and 3 Dfinite element software Midas GTS.The influence of stratum loss rate on pile settlement was also studied.The research results can provide references for engineering design and protection of surrounding buildings during construction.