| 循环与单调加载作用下冻结黄土的变形与损伤特性 |
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| 引用本文： | 徐湘田,赖远明,周志伟,谢胜波.循环与单调加载作用下冻结黄土的变形与损伤特性[J].冰川冻土,2014,36(5):1184-1191. |
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| 作者姓名： | 徐湘田 赖远明 周志伟 谢胜波 |
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| 作者单位： | 1. 内蒙古大学 交通学院, 内蒙古 呼和浩特 010070;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 |
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| 基金项目： | 国家自然科学基金;国家自然科学基金;国家自然科学基金;国家重点基础研究发展计划（973计划）;新疆维吾尔自治区自然科学基金;冻土工程国家重点实验室开放基金;内蒙古大学高层次人才引进科研项目 |
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| 摘 要： | 针对冻土工程中地基冻土体受力形式复杂、常处于变应力路径、反复加卸载作用问题, 开展了冻结黄土静力条件下的三轴加卸载试验与单调加载对比试验, 研究了两种应力路径下冻结黄土的变形和损伤特性. 通过对比发现, 加载方式对冻结黄土变形特性随围压的变化规律影响不大. 循环加卸载作用下, 冻结黄土的压密变硬增强了其抵抗变形的能力. 卸载阶段, 冻结黄土表现出卸载体胀的弹性现象, 呈现出与融土不同的体变特征. 基于弹性模量的劣化定义了冻结黄土的损伤变量, 并根据试验结果得出了冻结黄土的损伤演化规律可用双曲线函数来描述. 在较低的围压下, 围压增加对冻土损伤的发展有抑制作用; 而当围压足够大时, 由于冰的压碎和压融的出现, 围压增大加剧了损伤的发展.
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| 关 键 词： | 冻结黄土 加卸载 变形 损伤变量 |
| 收稿时间： | 2014-02-04 |
| 修稿时间： | 2014-06-26 |
Laboratory investigation on the deformation and damage characteristics of frozen loess under triaxial cyclic and monotonic loading conditions |
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| XU Xiangtian,LAI Yuanming,ZHOU Zhiwei,XIE Shengbo.Laboratory investigation on the deformation and damage characteristics of frozen loess under triaxial cyclic and monotonic loading conditions[J].Journal of Glaciology and Geocryology,2014,36(5):1184-1191. |
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| Authors: | XU Xiangtian LAI Yuanming ZHOU Zhiwei XIE Shengbo |
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| Institution: | 1. Institute of Transportation, Inner Mongolia University, Hohhot 010070, 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 |
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| Abstract: | The stress path, stress level and loading and unloading model of frozen soils are very complicated in permafrost engineering project. Thus, uniaxial and triaxial cyclic loading and unloading tests of artificially frozen loess were performed in order to understand the deformation and damage properties under two stress paths. Testing results showed that the loading method has slightly effects on deformation characteristics of frozen loess under different confining pressure conditions. The compaction and harden of frozen loess result in enhancing of capability in resist deformation under cyclic loading conditions. The elastic recovery of volumetric expansion can be observed in unloading stages, which is different to volumetric deformation characteristics of unfrozen soils. The damage variable is defined by the degradation of elasticity modulus. The damage-evolvement process of frozen loess can be described with hyperbolic functions. The damage of frozen loess is inhibited by the increase of confining pressure under low confining pressure condition. Also, the damage can be promoted by the increase of confining pressure along with crush and pressure melting under high confining pressure conditions. |
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| Keywords: | frozen loess loading-unloading deformation damage variable |
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