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冰川冻土 ›› 2022, Vol. 44 ›› Issue (2): 524-534.doi: 10.7522/j.issn.1000-0240.2022.0012

• 寒区工程与灾害 • 上一篇    

冻融循环作用下冻结掺和土料动力特性研究

王丹1,3(), 刘恩龙1,2(), 杨成松1   

  1. 1.中国科学院 西北生态环境资源研究院 冻土工程国家重点实验室, 甘肃 兰州 730000
    2.四川大学 水利水电学院, 四川 成都 610065
    3.中国科学院大学, 北京 100049
  • 收稿日期:2021-09-13 修回日期:2021-11-26 出版日期:2022-04-30 发布日期:2022-06-10
  • 通讯作者: 刘恩龙 E-mail:dwang1922@lzb.ac.cn;liuenlong@scu.edu.cn
  • 作者简介:王丹,博士研究生,主要从事冻土动力学及动力本构关系研究. E-mail: dwang1922@lzb.ac.cn
  • 基金资助:
    国家自然科学基金项目(41771066)

Influence of the freeze-thaw cycles on dynamic mechanical properties of frozen mixed soil

Dan WANG1,3(), Enlong LIU1,2(), Chengsong YANG1   

  1. 1.State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China
    2.College of Water Resources and Hydropower,Sichuan University,Chengdu 610065,China
    3.University of Chinese Academy of Sciences,Beijing 100049,China
  • Received:2021-09-13 Revised:2021-11-26 Online:2022-04-30 Published:2022-06-10
  • Contact: Enlong LIU E-mail:dwang1922@lzb.ac.cn;liuenlong@scu.edu.cn

摘要:

冻融循环作用是寒区土体力学性质改变的主要影响因素之一。为研究冻融循环作用下寒区冻结掺和土料的动力特性(包括动变形和动强度),以寒区高土石坝砾石掺和土坝料为研究对象,采用低温振动三轴材料试验机,对不同冻融循环次数(0、5、20次)下的冻结掺和土试样进行不同围压和不同动应力幅值比条件下的低温动力循环三轴试验,探讨冻融循环作用对冻结掺和土料的动应力-动应变关系,体变、滞回曲线,轴向累积应变,动回弹模量,残余应变以及动强度的影响。结果表明:随着冻融循环作用的增加,冻结掺和土料的动应力-动应变曲线和体变曲线逐渐稀疏,且试样达到破坏应变的振动次数呈线性减小。通过对不同冻融循环次数下冻结试样的滞回曲线、轴向累积应变、残余变形的研究,发现冻融循环作用使得试样抵抗变形的能力下降。随冻融循环次数的增加,试样的动回弹模量减小,动强度逐渐降低,试样更容易发生破坏。研究结果较好地解释了冻结掺和土料在冻融循环作用下动力变形的机制,可为基于动力变形控制的寒区工程基础设计提供科学参考。

关键词: 冻结掺和土料, 冻融循环, 动力循环三轴试验, 动力特征

Abstract:

To investigate the dynamic properties (including the dynamic deformation and dynamic strength) of frozen mixed soils subjected to the freeze-thaw cycles, a series of cyclic dynamic experiments were conducted through a cryogenic triaxial apparatus. With the variation of freeze-thaw cycles, a conspicuous influence on the dynamic stress-strain behaviors, volumetric strain curves, hysteresis loop, accumulative axial strain, dynamic resilient modulus, residual deformation, and dynamic strength of frozen mixed soil was analyzed. The results show that: (1) With the increase of the freeze-thaw cycles, the dynamic stress-strain curves and dynamic volumetric strain curves of frozen mixed soil gradually become looser, and the number of failures decreases linearly; (2) The action of freeze-thaw influences the variation of the hysteresis loop, the accumulative axial strain, the dynamic resilient modulus, and the residual deformation of frozen mixed soil, leading an unacceptable deformation; (3) The dynamic resilience modulus and the dynamic strength of frozen mixed soil are reduced with the number of freeze-thaw cycles increased.

Key words: frozen mixed soil, freeze-thaw cycle, dynamic triaxial test, dynamic mechanical properties

中图分类号: 

  • P642.14