›› 2017, Vol. 38 ›› Issue (S2): 330-336.doi: 10.16285/j.rsm.2017.S2.046

• 基础理论与实验研究 • 上一篇    下一篇

易破碎砂土地基中“平底桩”贯入数值模拟分析

吴则祥1,2,金银富2,季 慧1,尹振宇1,2,3,4   

  1. 1. 上海交通大学 土木工程系,上海 200240;2. 南特中央理工大学 土木工程系,法国 南特 44300; 3. 同济大学 岩土及地下工程教育部重点实验室,上海 200092;4. 同济大学 地下建筑与工程系,上海 200092
  • 收稿日期:2017-04-25 出版日期:2017-11-23 发布日期:2018-06-05
  • 基金资助:

    吴则祥,男,1987年生,博士研究生,主要从事岩土大变形计算等方面的研究。

Numerical simulation analysis of flat bottom pile drived into foundation of easily crushable sand

WU Ze-xiang1,2, JIN Yin-fu2, JI Hui1, YIN Zhen-yu1,2,3,4   

  1. 1. Department of Civil Engineering, Shanghai Jiaotong University, Shanghai 200240, China; 2. Department of Civil Engineering, Ecole Centrale de Nantes, Nantes 44300, France; 3. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China; 4. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China
  • Received:2017-04-25 Online:2017-11-23 Published:2018-06-05
  • Supported by:

    季慧,女,1976年生,博士,主要从事岩土实验及数值等方面的研究。

摘要: 桩在贯入砂土地基时所产生的高应力会引起桩周砂土的破碎,在易破碎砂土地基中更为严重。砂土破碎会引起桩基承载力的降低,严重地会导致基础结构物失稳甚至倒塌破坏。针对平底桩贯入易破碎砂土地基所产生的上述问题,引入新近提出的砂土颗粒破碎本构模型,结合耦合欧拉–拉格朗日(CEL)方法在处理大变形计算上的优势,对平底桩贯入过程进行了数值模拟研究。首先,根据Dog’s bay钙质砂的三轴剪切试验结果,确定了砂土破碎模型的模型参数。然后,采用CEL方法对平底桩贯入Dog’s bay钙质砂的离心机试验进行了模拟,模拟结果与试验测量结果吻合,表明所提出的平底桩贯入易破碎砂土地基的模拟方法的有效性和可行性,砂土破碎可明显降低桩基的承载能力。研究结果可为桩基贯入易破碎砂土地基提供设计和施工依据。

关键词: 桩;颗粒破碎;本构模型;耦合欧拉&ndash, 拉格朗日法(CEL);承载力;砂土

Abstract: The high-stress level caused by the pile driving can result in grain breakage of sand around the pile, which is more serious for the very easily crushable sand. The grain breakage will lead to the reduction of pile bearing capacity, which can result in the instability of foundation structures even collapse. In this paper, a numerical simulation analysis to investigate the problem of the pile driving into the foundation of very easily crushable sand is performed by adopting a newly developed sand breakage model combining with the Coupled Eulerian-Lagrangian(CEL) method. The model parameters are first calibrated and validated through simulating a series of triaxial tests of Dog’s bay carbonate sand. Then, the centrifuge pile driving tests performed on Dog’s bay carbonate sand are simulated by using the CEL technique. The simulated results have a good agreement with the experimental measurements, which demonstrates that the adopted breakage model associating with the CEL for solving the pile driving is effective and feasible. All the comparisons indicate that the bearing capacity of the pile is significantly decreased due to the grain breakage. The results are helpful for the design and construction of the pile driving into the foundation of very easily crushable sand.

Key words: pile, grain breakage, constitutive model, Coupled Eulerian Lagrangian(CEL), bearing capacity, sand

中图分类号: 

  • TU473

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