力学与实践 ›› 2014, Vol. 36 ›› Issue (1): 59-63.DOI: 10.6052/1000-0879-13-277

• 应用研究 • 上一篇    下一篇

砂土地基中开挖过程对立柱桩的影响分析

陈明, 李镜培   

  1. 同济大学地下建筑与工程系, 岩土及地下工程教育部重点试验室, 上海200092
  • 收稿日期:2013-06-28 修回日期:2013-09-11 出版日期:2014-02-08 发布日期:2013-12-25
  • 通讯作者: 陈明,1979年生,男,博士生,主要研究方向为地基处理、桩基础和基坑工程.E-mail:andychen79@126.com;李镜培,1963年生,男,教授,博士生导师,主要研究方向为土的工程性质、桩基础与深基础.E-mail:lijp2773@tongji.edu.cn
  • 基金资助:

    国家自然科学基金资助项目(41272288).

INFLUENCE OF EXCAVATION PROCESS IN SAND ON ERECT COLUMN PILES

CHEN Ming, LI Jingpei   

  1. Department of Geotechnical Engineering, Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China
  • Received:2013-06-28 Revised:2013-09-11 Online:2014-02-08 Published:2013-12-25

摘要:

立柱桩对基坑工程的稳定性有重要影响. 基于快速拉格朗日法(fast Lagrangian analysis of continua-3D, FLAC3D),考虑桩土之间的相对滑移作用,深入分析了砂土地基中开挖条件下不同布桩方式对立柱桩桩身拉力、最大拉力位置及桩顶回弹量等的影响. 结果表明:开挖对立柱桩的影响有明显的空间效应,开挖对中心桩的影响最大,角桩最小;开挖使立柱桩桩身内产生了拉力,群桩基础内的中心桩最大拉力值大于 单桩的最大拉力值,且最大拉力值位置随桩数的增加而上移,并最终稳定在0.5倍的有效桩长;中心桩桩顶回弹量先随着桩数的增加而增大,然后当桩数增加到一定的数量后减小.

关键词:

深开挖|空间效应|桩身拉力|桩顶回弹

Abstract:

The erect column piles have an important effect on the stability of the foundation pit. Based on the three-dimensional explicit finite-difference program, this paper analyzes the impact of the tension force, the location of the maximum tension force and the heave of piles on the column piles with consideration of the interaction between soil and piles. It is shown that the influence of the excavation on the erect column piles has an obvious spatial characteristic, with the maximum influence on the center pile and the minimum on the corner pile. The tension force is induced by excavation, the location of the maximum value moves upward of the column pile, and finally stops at half of the effective insertion depth of pile foundation, the maximum tension force of the center pile in pile group is larger than that of a single pile; the heave of the pile top increases with the numbers of piles, and then decreases when the pile number is increased to a certain value.

Key words:

deep excavation|spatial effect|tension force of pile|heave of pile top

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