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冰川冻土 ›› 2018, Vol. 40 ›› Issue (2): 346-354.doi: 10.7522/j.issn.1000-0240.2018.0039

• 寒区科学与技术 • 上一篇    下一篇

冻结砂土体积变形影响因素的敏感性分析

高娟1,2, 廖孟柯3, 常丹1,4, 白瑞强1,2   

  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. 中国科学院大学, 北京 100049;
    3. 国网新疆电力公司 经济技术研究院, 新疆 乌鲁木齐 830002;
    4. 北京交通大学, 北京 100044
  • 收稿日期:2018-01-01 修回日期:2018-03-02 出版日期:2018-04-25 发布日期:2018-07-02
  • 作者简介:高娟(1988-),女,甘肃静宁人,2014年在中国矿业大学(徐州)获硕士学位,现为中国科学院西北生态环境资源研究院在读博士研究生,从事冻土力学研究.E-mail:gaojuan2611261@lzb.ac.cn
  • 基金资助:
    国家自然科学基金项目(41230630;41701068);中国科学院前沿科学重点研究计划项目(QYZDY-SSW-DQC015)资助

Sensitivity analysis of the factors affecting the volumetric deformation of frozen sandy soil

GAO Juan1,2, LIAO Mengke3, CHANG Dan1,4, BAI Ruiqiang1,2   

  1. 1. State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. Economic and Technological Research Institute, State Grid Electric Power of Xingjiang, Vrümqi 830002, China;
    4. Beijing Jiaotong University, Beijing 100044, China
  • Received:2018-01-01 Revised:2018-03-02 Online:2018-04-25 Published:2018-07-02

摘要: 为了分析三轴试验中冻土体积变形影响因素的敏感性,选定包括内因和外因在内的6种影响因素,选用青海省德令哈的砂土按照正交试验方案进行常规三轴试验,并采用灰色关联分析法对试验结果进行分析,给出各影响因素的敏感性排序。结果表明,在选定的6种影响因素中,含水率、加载速率及温度的敏感性超过70%,需重点考虑。在较小含水率条件下,冻结砂土先体缩再体胀,且应力峰值点和应变峰值点所对应的轴向应变基本一致,而在饱和条件下仅发生体积膨胀。加载速率对冻土的影响主要表现为对其力学特性和破坏形态的改变,随着加载速率的增加冻土的体缩量、切线模量和峰值强度增加,但峰值应变却表现为减小趋势,冻结砂土性质趋近脆性。土样温度降低,土颗粒间的黏结力增加,孔隙压力转变为有效应力,从而导致冻结砂土的强度增加、体积膨胀量增加。分析结果可为相关试验及工程优化设计提供一定的参考。

关键词: 冻结砂土, 体积变形, 灰色关联分析, 敏感性分析

Abstract: In order to analyze the sensitivity of the factors affecting volumetric strain of frozen sandy soil, six internal and external affecting factors have been selected in this paper. According to the method of orthogonal experiment design, using the sandy soil from Delingha of Qinghai Province, a number of triaxial compression tests were conducted. The results were analyzed by using the grey relational analysis (GRA), the magnitude of the sensitivity of all the selected influencing factors and the sequence of them was given. The results showed that the sensitivity of water content, loading rate and temperature are more than 70%, so these factors need to be considered during the later experiments. With small water content, the volumetric strain of frozen sandy soil shows contraction first and then expansion; the axial strains corresponding to the peak stress and the peak strain are basically the same, while in saturated condition, the volumetric strain only shows volume expansion; the major influence of loading rate on frozen sandy soil was the change of the mechanical properties and failure forms. With the increase of loading rate, the amount of volumetric strain decreases, tangent modulus and peak strength increase, while the peak strain shows a decreasing tendency, the properties of frozen sandy soil approach brittleness. When temperature decreases, the cohesive force between particles increases and the pore pressure transforms into effective stress, which will increase strength and volume expansion. The results of this paper will be useful for optimal design of laboratory test and engineering application.

Key words: frozen sandy soil, volumetric deformation, grey relational analysis (GRA), sensitivity analysis

中图分类号: 

  • TU411.3