土工基础

土工基础 ›› 2020, Vol. 34 ›› Issue (2): 171-175.

• 专题论述 • 上一篇    下一篇

新建桥梁桩基对既有桥梁桩基影响的数值分析

李发达1，凌贤长1,2，苏 雷1，杨忠年1   

  1. （1.青岛理工大学土木工程学院，山东青岛 266033；2.哈尔滨工业大学土木工程学院，哈尔滨 150090）
  • 收稿日期:2019-06-17 修回日期:2019-07-01 出版日期:2020-05-20 发布日期:2020-05-20
  • 作者简介:李发达（1990-），男，硕士研究生，研究方向为桩基数值模拟及室内模型试验。
  • 基金资助:
    泰山学者工程专项经费(2015-212)；山东省自然科学基金资助项目(ZR2017QEE007)；中国博士后科学基金项目(2017M622158)

Numerical Analysis of the Influence on the Proposed Pile Adjacent to the Existing Piled Bridge Foundations

LI Fada1, LING Xianzhang1,2, SU Lei1, YANG Zhongnian1   

  1. (1.School of Civil Engineering, Qingdao University of Technology, Qingdao 266033;
    2.School of Civil Engineering, Harbin Institute of Technology, Harbin 150090)
  • Received:2019-06-17 Revised:2019-07-01 Online:2020-05-20 Published:2020-05-20

摘要： 随着我国高速铁路的快速发展，新建铁路与既有铁路交叉跨越已是不可避免的现象。桩基作为铁路桥梁工程中最常用的基础型式，在实际工程中新建桥梁桩基对既有桥梁桩基的影响已成为桩基工程中研究的热点之一。如何评价新建桥梁桩基对既有桥梁桩基影响是一个不可忽视的工程问题。在本文中，根据实际工程背景，基于OpenSees开源有限元数值计算平台，土体采用多屈服面弹塑性本构模型，群桩采用弹性梁柱单元模拟，建立相应的三维数值计算模型。通过轴力和位移响应，探讨新建桥梁桩基对既有桥梁桩基的影响。数值计算结果表明：①新建桥梁桩基距既有桥梁桩基9.71 m处，新建桥梁桩基对既有桥梁桩基轴力有明显的影响，使既有桩基轴力增大25%；②新建桥梁桩基对既有桥梁桩基的位移有一定影响，对靠近新建桥梁桩基竖向位移影响最大，使其既有桩基竖向位移增加45%。上述研究可为类似工程实例的模拟提供借鉴和参考。

关键词: 铁路桥梁, 桥梁桩基, 群桩, 三维有限元, 数值模拟

Abstract: With the rapid development of China's high-speed railway, it is common that the proposed railway bridges cross the existing railway alignments. As the piled foundations are extensively used in the railway projects, the influence of the proposed piled bridge foundations on the existing pile supported footings has become one of the concerned topics in the pile foundation engineering practice. How to evaluate the impact of the proposed piled foundations on the existing footings is a critical engineering issue. In this paper, using a practical engineering background, a threedimensional numerical model is established by using software OpenSees, which is an open source finite element analysis platform. The multiyield surface elastoplastic constitutive model was used for soils and the pile foundation was simulated by the elastic beamcolumn element. Through the response of the axial force and displacement, the influence of the proposed piled foundation on the existing footing structure was evaluated. The numerical results show that: (1) when the distance between the proposed piled foundation and the existing footing is 9.71 m, the proposed piled foundation has an obvious influence on the axial force of the existing piles, which increases the axial force in the existing pile foundation by 25%; (2) The proposed piled foundation has a certain influence on the displacement of the existing deep foundations, and has the greatest influence on the vertical displacement of the existing footings, among other factors. This influence increases the vertical displacement at the existing pile foundation by up to 45%. The numerical analysis results provide could a guide and reference for the study of the similar engineering projects.

Key words: railway bridges, piled foundations for bridges, pile groups, three-dimensional finite element analysis, numerical simulation

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