土工基础

›› 2016, Vol. 30 ›› Issue (4): 476-480.

• 工程实录 • 上一篇    下一篇

基坑开挖中群桩受力及变形性状的三维有限元分析

赵 歆1，3，路明月2，3，段贤明3   

  1. （1.天津市市政工程设计研究院，天津 300051； 2.天津港航工程有限公司，天津 300457； 3.天津大学 土木工程系，天津 300072）
  • 收稿日期:2015-10-19 出版日期:2016-08-20 发布日期:2016-08-26
  • 作者简介:赵 歆（1988-），男，助理工程师，研究方向为地下工程。

3D Finite Element Analysis of the Deep Excavation on the Stress and Strain in Pile Groups

ZHAO Xin1,3, LU Mingyue2,3， DUAN Xianming3   

  1. (1.Tianjin Municipal Engineering Design and Research Institute, Tianjin 300051；
    2.Tianjin Port & Channel Engineering Company, Tianjin 300457；
    3.Department of Civil Engineering, Tianjin University, Tianjin 300072)
  • Received:2015-10-19 Online:2016-08-20 Published:2016-08-26

摘要： 通过有限元计算，研究了大面积深基坑开挖对群桩的受力和变形特性的影响。群桩基础的受力及变形性状明显不同于单桩。对于坑底群桩，随着基坑开挖深度增加，桩身轴力随之增加，桩身轴力最大值位置由桩身中上部转移到中部，与单桩的轴力最大值位置（桩身中下部）有一定程度的差别。在同一开挖深度中，距离地下连续墙近的桩身轴力较小，距离基坑中心近的桩身轴力较大。其主要原因是基坑中心处的土体回弹大于基坑边部，相应的桩土位移及桩侧摩阻力发挥程度也较大。由于基坑开挖造成支护结构发生侧向变形，使得靠近支护结构的桩产生弯曲，整体表现为桩身上部变形较大，中下部变形较小。

关键词: 基坑开挖, 群桩, 有限元

Abstract: The large deep excavation of the stress and strain in pile groups was analyzed with three dimensional finite elements analyses. The stress strain characteristics in the pile group are significantly different from those of in the single pile. For pile groups under the bottom of the excavation, the axial stress in the pile increases in the depth of the excavation. The location of the maximum force in the pile changes from the top to the middle part of the pile. Whereas, in the single pile (without pile cap), the maximum axial force is located at the lower portion of the pile. At the same excavation depth, the smaller axial force could be found in piles near the slurry wall; large axial force can be found in piles that are close to the center of the excavation with a larger pile deformation and mobilized side resistance in piles. Due to the lateral deformation of the supporting structures, piles that are closed to the supporting structures have large bending moments. As a result, these piles have large deformation in the upper portion of the pile.

Key words: Deep Excavations, Pile Groups, Finite Element Methods