| 动荷载作用下冻结兰州黄土的动应变幅变化特征研究 |
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| 引用本文： | 罗飞,赵淑萍,马巍,焦贵德.动荷载作用下冻结兰州黄土的动应变幅变化特征研究[J].冰川冻土,2012,34(4):884-890. |
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| 作者姓名： | 罗飞 赵淑萍 马巍 焦贵德 |
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| 作者单位： | 1. 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;2. 四川农业大学 城乡建设学院, 四川 都江堰 611830;3. 兰州大学 西部灾害与环境力学教育部重点实验室, 甘肃 兰州 730000 |
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| 基金项目： | 中国科学院“西部之光”重点项目“列车荷载作用下青藏铁路冻土路基的动力响应特性研究”，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自主课题，国家自然科学基金项目 |
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| 摘 要： | 采用分级循环正弦荷载模拟车辆振动, 通过动三轴试验对冻土的动应变幅进行了研究. 结果表明: 对于频率为0.1 Hz的前5级加载和频率≥0.5 Hz的各级加载作用下的动应变幅, 可以采用等价应变幅描述每一级动荷载作用下的动应变幅. 存在一个临界频率(约为7 Hz), 当加载频率小于该临界频率时, 等价应变幅变化复杂; 当加载频率大于该临界频率时, 等价应变幅随加载级数基本保持不变. 当加载频率≥0.5 Hz时,不同加载级数下等价应变幅随加载频率的增大而减小. 围压对等价应变幅影响较小; 当频率≤0.5 Hz时, -0.5 ℃条件下的等价应变幅略大于-1.0 ℃条件下的等价应变幅; 当频率>0.5 Hz时, 不同温度下的等价应变幅近似相等.
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| 关 键 词： | 分级动荷载 冻土 动应变幅 等价应变幅 临界频率 |
| 收稿时间： | 2011-11-12 |
| 修稿时间： | 2012-01-22 |
Characteristics of Dynamic Strain Amplitude of Frozen Lanzhou Loess under Dynamic Loading |
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| LUO Fei,ZHAO Shu-ping,MA Wei,JIAO Gui-de.Characteristics of Dynamic Strain Amplitude of Frozen Lanzhou Loess under Dynamic Loading[J].Journal of Glaciology and Geocryology,2012,34(4):884-890. |
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| Authors: | LUO Fei ZHAO Shu-ping MA Wei JIAO Gui-de |
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| Institution: | 1. State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering ResecorchInstitate, Chinese Academy of Sciences, Lanzhou Gansu 730000, China;2. Urban and Rural Construction College, Sichuan Agricultural University,Dujiangyan Sichuan 611830, China;3. School of Civil Engineering and Mechanics, Lanzhou University, Lanzhou Gansu 730070, China |
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| Abstract: | Based on dynamic tri-axial tests at low temperature,dynamic strain amplitude of frozen soil was studied under vehicle vibration load,which was simplified as staged and cyclic sinusoidal load.The research results show that the equivalent dynamic strain amplitude can be used to describe the dynamic strain amplitude under each stage load when the vibration frequency is greater than or equal to 0.5 Hz for each stage load and is equal to 0.1 Hz for the initial five stage loads.The equivalent dynamic strain amplitude is very complicated with the increasing load when the vibration frequency is less than the critical vibration frequency,approximately equal to 7 Hz,and basically remains constant when the vibration frequency is greater than the critical vibration frequency.The equivalent dynamic strain amplitude decreases with increasing vibration frequency when the vibration frequency is greater than or equal to 0.5 Hz.Confining pressure has nearly no impact on the equivalence dynamic strain amplitude.The equivalent dynamic strain amplitude under-0.5 ℃ is slightly greater than that under-1 ℃ when the vibration frequency is less than or equal to 0.5 Hz.The value of the equivalent dynamic strain amplitude is approximately unanimous when the vibration frequency is greater than 0.5 Hz. |
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| Keywords: | staged dynamic loading frozen soil dynamic strain amplitude equivalent dynamic strain amplitude critical frequency |
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