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冰川冻土 ›› 2014, Vol. 36 ›› Issue (6): 1471-1478.doi: 10.7522/j.issn.1000-0240.2014.0175

• 寒区科学与技术 • 上一篇    下一篇

基于水-热-力耦合模型的钻孔灌注桩承载力影响因素分析

刘乃飞1, 李宁1, 何敏1, 徐栓海1   

  1. 1. 西安理工大学 岩土工程研究所, 陕西 西安 710048;
    2. 中国科学院 寒区旱区环境与工程研究所 冻土工程国家重点实验室, 甘肃 兰州 730000;
    3. 中国电建集团 西北勘测设计研究院有限公司, 陕西 西安 710065;
    4. 中煤科工集团 西安研究院有限公司, 陕西 西安 710077
  • 收稿日期:2014-01-20 修回日期:2014-11-22 出版日期:2014-12-25 发布日期:2015-01-20
  • 作者简介:刘乃飞(1985-),男,陕西榆林人,2012年在西安理工大学获硕士学位,现为在读博士研究生,主要从事寒区岩土工程水-热-力三场耦合方面的研究工作.E-mail:liunaifei1985@126.com
  • 基金资助:
    西安理工大学博士学位论文创新基金项目(207-002J1306); 国家自然科学基金创新群体项目(40821001)资助

Analyzing the factors controlling the bearing capacity of cast-in-place piles based on a thermo-hydro-mechanical coupling model

LIU Naifei1, LI Ning1, HE Min1, XU Shuanhai1   

  1. 1. Institute of Geotechnical Engineering, Xi'an University of Technology, Xi'an 710048, China;
    2. State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;
    3. Xibei Engineering Corporation Limited of the Power Construction Corporation of China, Xi'an 710048, China;
    4. Xi'an Research Institute of China Coal Technology & Engineering Group Corp, Xi'an 710077, China
  • Received:2014-01-20 Revised:2014-11-22 Online:2014-12-25 Published:2015-01-20

摘要: 针对广大寒区普遍存在的冻胀-融沉影响桩基承载力问题, 以清水河大桥灌注桩为例, 基于建立的饱和冻土水-热-力三场耦合模型及研发的3G2012软件系统, 深入研究了温度变幅、桩和地基土的传导系数、导水系数、回冻时间等因素对其承载力的影响, 揭示了其承载的内在热力学机理. 结果表明: 钻孔灌注桩承载力随温度发生波动变化, 冬季桩基的极限承载力近似为夏季的1.2倍; 地基的导水系数提高一个数量级, 加剧了地基土中的水分迁移及冻胀融沉变形, 进而影响桩基承载力; 冻土回冻时间对桩基承载力也有较大影响. 以上结论为寒区岩土工程的设计与施工提供量化的科学依据.

关键词: 水-热-力耦合模型, 钻孔灌注桩, 承载力, 含冰量

Abstract: The bearing capacity of pile foundation is severely affected by the changes in seasonally freezing and thawing processes. By using a thermo-hydro-mechanical coupling model for saturation frozen soil and its analysis software 3G2012, the influences of temperature fluctuation, conductivity coefficient, transmissibility coefficient and refreezing time on the bearing capacity of cast-in-place pile in cold regions are studied in this paper, in which the cast-in-place piles in Qingshuihe Bridge are taken as an example. The study achievements reveal the thermo-dynamics mechanism of the bearing capacity of cast-in-place pile. It is found that 1) bearing capacity shows a fluctuate change with temperature and the ultimate bearing capacity of the pile foundation in winter is about 120% as it in summer; 2) when the transmissibility coefficient within subsoil has one order enhanced, the water migration will be more active and the frost heaving and thawing settlement processes will significantly intensify, affecting the pile's bearing capacity; 3) also, the process of refrozen has some influence on the bearing capacity of the pile. Further study may provide scientific basis for design and construction of projects in cold regions.

Key words: thermo-hydro-mechanical (THM) coupling model, cast-in-place pile, bearing capacity, ice content

中图分类号: 

  • P642.14