| 水汽补给下砂土冻胀量与微观结构参数关联研究 |
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| 引用本文： | 雷华阳,张文振,霍海峰,冯双喜,李其昂,刘汉磊.水汽补给下砂土冻胀量与微观结构参数关联研究[J].岩土力学,2022,43(9):2337-2346. |
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| 作者姓名： | 雷华阳 张文振 霍海峰 冯双喜 李其昂 刘汉磊 |
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| 作者单位： | 1. 天津大学 建筑工程学院，天津 300354；2. 天津大学 滨海土木工程结构与安全教育部重点实验室，天津 300354；
3. 中国地震局 地震工程综合模拟与城乡抗震韧性重点实验室，天津 300354；4. 中国民航大学 交通科学与工程学院，天津 300300 |
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| 基金项目： | 国家自然科学基金（No.52078334）；国家重点研发计划项目（No.2017YFC0805402）；土木工程防灾国家重点实验室开放基金项目（SLDRCE17-01）。 |
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| 摘 要： | 水汽补给可诱发砂土填料的冻胀。基于自主研发的水汽迁移和冻胀试验仪，研究了气态水补给下砂土含水率、温度和冻胀量变化规律；利用体视显微镜对冻结过程中砂土微观结构变化特征进行了研究，结合灰色关联理论分析了宏观指标冻胀量与微观参数之间的关联关系。结果表明：在水汽补给下砂土会发生明显冻胀，冻结 7 d 时冻胀量达到 3.45 mm。砂土经历冻胀后，大孔隙面积占比增加、中小微孔隙面积占比降低，孔隙数量占比变化趋势与面积占比相反，孔隙丰度值变化不大，孔隙定向角在各区间分布趋于更加均匀，孔隙定向概率熵整体呈震荡上升趋势，孔隙分形维数呈下降趋势。此外，利用灰色关联理论，建立了宏观参数冻胀量与平均孔径等微观参数之间的关联关系式，进一步揭示了水汽补给下砂土冻胀的微观机制。
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| 关 键 词： | 砂土 水汽补给 冻胀量 微观结构 微观参数 |
| 收稿时间： | 2021-11-26 |
| 修稿时间： | 2022-05-06 |
Correlation between frost heave and microscopic parameters of sand under water vapor recharge |
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| LEI Hua-yang,ZHANG Wen-zhen,HUO Hai-feng,FENG Shuang-xi,LI Qi-ang,LIU Han-lei.Correlation between frost heave and microscopic parameters of sand under water vapor recharge[J].Rock and Soil Mechanics,2022,43(9):2337-2346. |
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| Authors: | LEI Hua-yang ZHANG Wen-zhen HUO Hai-feng FENG Shuang-xi LI Qi-ang LIU Han-lei |
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| Institution: | 1. Department of Civil Engineering, Tianjin University, Tianjin 300354, China;
2. Key Laboratory of Coast Civil Structure Safety of Education Ministry, Tianjin University, Tianjin 300354, China;
3. Key Laboratory of Comprehensive Simulation of Engineering Earthquake and Urban-Rural Seismic Resilience, China Earthquake Administration, Tianjin 300350, China; 4. School of Transportation Science and Engineering, Civil Aviation University of China, Tianjin 300300, China |
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| Abstract: | Water
vapor supply can induce frost heave of sand filler. Based on the self-developed
moisture migration and frost heaving tester, the variations of sand moisture
content, temperature and frost heave with freezing time under gaseous water
recharge were studied. The change characteristics of sand microstructure during
freezing were examined by stereomicroscope. By combining with the grey
correlation theory, the correlation between the macroscopic index, i.e., frost
heave and the microscopic parameters was analyzed. Notable frost heaving was
observed under water vapor supply, and the frost heave reached 3.45 mm after 7
days of freezing. After sandy soil frost heaving, the proportion of large pore
area increased and the proportions of small and medium micropore area decreased,
and the change trend of pore number proportion was opposite to that of area
proportion, while pore abundance value changed little, pore orientation angle distribution
in each interval tended to be more uniform, the probability entropy of pore
orientation present an overall upward trend of oscillation, and the pore
fractal dimension showed a trend of decrease. In addition, the grey correlation
theory is used to establish the correlation between the frost heave and the
average pore size and other microscopic parameters, which provides an insight
into the microscopic mechanism of sand frost heaving under water vapor supply. |
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| Keywords: | sandy soil water vapor supply frost heave microstructure characteristics microstructure parameter |
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