上海交通大学学报 ›› 2022, Vol. 56 ›› Issue (6): 754-763.doi: 10.16183/j.cnki.jsjtu.2021.077

• 船舶海洋与建筑工程 • 上一篇    下一篇

基于统一强度理论的螺纹桩承载力计算方法

马甲宽a, 罗丽娟a,b(), 任翔a, 时航a, 尹怡墨a   

  1. a.长安大学 建筑工程学院,西安 710064
    b.长安大学 地下结构与工程研究所,西安 710064
  • 收稿日期:2021-03-10 出版日期:2022-06-28 发布日期:2022-07-04
  • 通讯作者: 罗丽娟 E-mail:luojuan@chd.edu.cn
  • 作者简介:马甲宽(1993-),男,河南省濮阳市人,博士生,主要从事桩基础工程方面研究.
  • 基金资助:
    国家自然科学基金(42077248);国家自然科学基金(41877285);中央高校基本科研业务费(300102289201)

Calculation Method of Bearing Capacity of Screw Pile Based on Unified Strength Theory

MA Jiakuana, LUO Lijuana,b(), REN Xianga, SHI Hanga, YIN Yimoa   

  1. a. School of Civil Engineering, Chang’an University, Xi’an 710064, China
    b. Institute of Underground Structure and Engineering, Chang’an University, Xi’an 710064, China
  • Received:2021-03-10 Online:2022-06-28 Published:2022-07-04
  • Contact: LUO Lijuan E-mail:luojuan@chd.edu.cn

摘要:

基于统一强度理论及太沙基极限平衡原理推导了螺纹桩极限承载力,提出了螺纹桩螺牙单独承载破坏与圆柱形剪切破坏两种模式下临界螺距的确定方法和极限承载力计算方法,讨论了统一强度理论参数b与螺纹桩关键参数对极限承载力的影响.结果表明:螺纹桩的极限承载力是同外径圆桩的1.5~2倍,螺牙提供的极限承载力主要由土体黏聚力、内摩擦角及埋深决定.当b从0增加到1时,螺纹桩极限承载力理论计算值增幅约48%,考虑中主应力对土体强度的影响会使得螺纹桩承载力理论计算结果更加准确.螺纹桩的参数中,螺牙高度bh对其极限承载力影响最大,而螺牙厚度t对承载力基本无影响.设计螺纹桩时可适当增加螺牙高度,以提高螺纹桩极限承载力.

关键词: 螺纹桩, 统一强度理论, 现场监测, 太沙基极限平衡原理, 临界螺距

Abstract:

Based on the unified strength theory and the Terzaghi limit equilibrium theory, the ultimate bearing capacity of screw pile has been deduced. The method to determine the critical pitch and calculate the ultimate bearing capacity of the screw pile in two failure modes including the independent bearing failure mode and the cylinder shear failure mode has been proposed. The influence of the unified strength theoretical parameter b and the key parameters of concrete screw pile on the ultimate bearing capacity has been analyzed. The results show that the ultimate bearing capacity of the screw pile is 1.5—2 times that of the round pile with the same outer diameter. The ultimate bearing capacity of the screw teeth is mainly determined by the cohesion, the internal friction angle, and the buried depth of the soil. As b increases from 0 to 1, the theoretical value of the ultimate bearing capacity of the screw pile increases by nearly 48%. As the influence of the medium principal stress on the soil strength is considered, the theoretical calculation results of the bearing capacity of the concrete screw pile will be more accurate. Of the parameters of the concrete screw pile, the screw height bh has the greatest influence on the ultimate bearing capacity, while the screw thickness t has little influence on the bearing capacity. When designing threaded pile, the height of screw can be increased to some extent to improve the ultimate bearing capacity of the screw pile.

Key words: screw pile, unified strength theory, field monitoring, Terzaghi limit equilibrium principle, critical screw pitch

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