长江科学院院报 ›› 2019, Vol. 36 ›› Issue (9): 110-114,120.DOI: 10.11988/ckyyb.20180936

• 岩土工程 • 上一篇    下一篇

桩长对桩与桩相互作用影响的试验研究

张帅1,肖昭然2,赵宪强3,4,蒋敏敏2   

  1. 1.郑州市轨道交通有限公司,郑州 450002;
    2.河南工业大学 土木建筑学院,郑州 450001;
    3.南京水利科学研究院 岩土工程研究所,南京 210029; 4.河海大学 土木与交通学院,南京 210098
  • 收稿日期:2018-08-28 修回日期:2018-09-16 出版日期:2019-09-01 发布日期:2019-09-12
  • 通讯作者: 赵宪强(1990-),男,河南开封人,助理工程师,博士研究生,主要从事地下结构等方面的研究。E-mail: 280846242@qq.com
  • 作者简介:张 帅(1982-),男,辽宁锦州人,高级工程师,主要从事地下结构等方面的研究。E-mail: 2522632545@qq.com
  • 基金资助:
    国家自然科学基金项目(51178165,51408197);河南省科技厅自然科学项目(162102210188,15A560020)

Influence of Pile Length on the Interaction Between Piles

ZHANG Shuai1, XIAO Zhao-ran2, ZHAO Xian-qiang3,4, JIANG Min-min2   

  1. 1.Zhengzhou City Rail Transit Co., Ltd., Zhengzhou 450002, China;
    2.College of Civil Engineering and Architecture, Henan University of Technology, Zhengzhou 450001, China;
    3.Department of Geotechnical Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China;
    4.College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, China
  • Received:2018-08-28 Revised:2018-09-16 Online:2019-09-01 Published:2019-09-12

摘要: 为明确桩长对静压沉桩全过程中桩与桩之间相互作用产生影响的机理,通过室内模型试验,在中密实砂土中以2倍桩径为间距沉入双桩,研究了桩长对端阻力、卸除顶压后的桩周土压力以及双桩承载力特性的影响。结果表明:沉入过程中先沉桩和后沉桩的压入端阻力均随沉桩深度的增加而近似线性增大,当桩长(沉桩完成后沉入的总长度)为600 mm时,后沉桩仅比先沉桩的端阻力高0.2%左右,即此深度处2根桩的压桩端阻力基本达到极值;后压桩沉入前先沉桩的桩周土压力为后沉桩的90%左右,而后沉桩卸除顶压后先沉桩的桩周土压力总体为后沉桩的2~3倍,且随土压力盒埋深的增加而增大;相同深度桩周土压力均随桩长增大而降低;单桩试验时桩体极限承载力略高于先沉桩极限承载力2%~5%,提高的幅度随桩长增加而降低;不考虑桩间土作用双桩系统极限承载力约为单桩试验时极限承载力的2倍。研究成果对于进一步明确桩与桩相互作用机理和改善双桩承载力特性等均具有重要的工程意义。

关键词: 桩基础, 静压桩, 端阻力, 桩周土压力, 承载力, 桩与桩相互作用, 模型试验

Abstract: The impacts of pile length on end resistance of jacking pile, surrounding earth pressure after unloading, and bearing capacity of double piles were investigated through indoor model test of jacking double piles in modera-tely dense sand. Pile length in this paper is defined as the total length buried in sand when pile jacking is finished.Results demonstrated that the pressed end’s resistance of both piles increased approximately linearly with the deepening of pile jacking; at depth 600 mm at the finish of pile jacking, the end resistance of pile 1# (which is pressed firstly) was larger than that of pile 2# (referring to the pile pressed later) by about 0.2%, indicating that the end resistance of two piles reached the extreme value at this depth. Given the same pile length, the surrounding earth pressure of pile 1# before the sinking of pile 2# was about 90% of that of pile 2#; after the unloading of pile 2#, the surrounding earth pressure of pile 2# was about 2~3 times of that of pile 1#, and in the meantime increased with the increasing of embedded depth of pressure gauge. However, at the same buried depth, the surrounding earth pressure of the two piles both decreased with the increase of pile length. The ultimate bearing capacity of pile in single pile test was higher than that of pile 1# in double pile test by about 2%~5%, but such increment attenuated with the increasing of pile length. The ultimate bearing capacity of double pile system in no consideration of pile interaction was about twice times of single pile. The research findings are of engineering significance in further clarifying the interaction mechanism between piles and improving the bearing capacity of double piles.

Key words: pile foundation, jacked pile, end resistance, surrounding earth pressure, bearing capacity, interaction between pile and pile, model test

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