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冰川冻土 ›› 2019, Vol. 41 ›› Issue (3): 595-605.doi: 10.7522/j.issn.1000-0240.2019.0515

• 寒区科学与技术 • 上一篇    下一篇

高温冻结粉土力学特性试验研究

宋丙堂1,2, 刘恩龙1,3, 张德1,2, 刘星炎1,2, 张革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. 四川大学 水利水电学院, 四川 成都 610065
  • 收稿日期:2018-09-14 修回日期:2018-12-29 出版日期:2019-06-25 发布日期:2019-09-10
  • 通讯作者: 刘恩龙,E-mail:liuenlong@lzb.ac.cn. E-mail:liuenlong@lzb.ac.cn
  • 作者简介:宋丙堂(1991-),男,甘肃白银人,2016年在兰州交通大学获学士学位,现为中国科学院西北生态环境资源研究院在读硕士研究生,从事冻土本构模型研究.E-mail:1061208525@qq.com
  • 基金资助:
    国家自然科学基金项目(41771066);中国科学院"百人计划"(刘恩龙)资助

Experimental study on the mechanical properties of warm frozen silt soils

SONG Bingtang1,2, LIU Enlong1,3, ZHANG De1,2, LIU Xingyan1,2, ZHANG Ge1,2   

  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. College of Water Resources and Hydropower, Sichuan University, Chengdu 610065, China
  • Received:2018-09-14 Revised:2018-12-29 Online:2019-06-25 Published:2019-09-10

摘要: 为了探讨高温冻结粉土的力学特性,进行了一系列常规三轴压缩和三轴压缩加卸载试验。结果表明:(1)随着围压的增大,应力应变曲线先表现为应变软化,后应变硬化,最后又应变软化。(2)体积应变曲线均表现为先体缩后体胀,且围压越大,体胀越弱。(3)通过引入改进的双曲线模型,能较好地模拟应变软化和硬化特性。在q-p平面内建立了一个新的强度准则,并利用修正Mohr-Coulomb屈服准则,探讨了黏聚力c和内摩擦角φ的变化规律。根据试验结果,确定了不同围压及不同加卸载循环次数下高温冻结粉土的回弹模量及其损伤变化规律。最后,建立了塑性体积变形和塑性剪切变形之间的关系式和表达式,进一步探讨了高温冻结粉土的剪胀特性。

关键词: 高温冻结粉土, Mohr-Coulomb屈服准则, 强度特性, 损伤特性, 剪胀特性

Abstract: In order to investigate the mechanical properties of warm frozen silt soils, a series of triaxial compression tests and repeated shear loading-unloading tests were conducted. Experimental results indicated that:(1) with the increasing of the confining pressures, the stress-strain changing from strain softening to strain hardening, then strain softening occurred again; (2) the volumetric curves presented a compressive tendency at first, followed by a dilation; the higher the confining pressures were, the smaller the dilation phenomenon would become; (3) the stress-strain curves, which presented strain softening and hardening phenomenon, were well simulated by an improved hyperbolic model. A new strength criterion was proposed in q-p plane, which could well describe the evolution of increasing first and then decreasing with increasing of mean effective stress. The regularities of cohesion c and internal frictional angle φ for warm frozen silt soils were investigated on the basis of the modified Mohr-Coulomb yield criterion. According to the repeated triaxial shear loading-unloading tests, the resilient modulus of warm frozen silt soils were determined with different loading-unloading cycles under different confining pressures. At the same time, the damage evolution was explored. Finally, the relationship between plastic volumetric strain and plastic shear strain was established and expressed by an empirical mathematical formulation. Later, the characteristics of dilatancy were investigated under different confining pressures as well.

Key words: warm frozen silt soils, Mohr-Coulomb yield criterion, strength properties, damage behaviors, dilation characteristics

中图分类号: 

  • TU445