青藏粉质黏土冻融过程水热特征研究

发布时间：2018-03-26 05:43

本文选题：冻融　切入点：未冻水含量　出处：《冰川冻土》2017年04期

【摘要】：土体在冻融过程中的水热特征对于冻胀及工程稳定性具有决定性作用。以青藏粉质黏土为例,采用时域反射法(TDR),测量并分析了不同初始含水率条件下的土样在冻融过程中的水热变化特征,对比了冻融过程中的水热变化及其差异性,采用Anderson等、徐ei祖等和Michalowski提出的以温度为变量的未冻水计算公式,分别计算了不同初始含水率土样在不同温度条件下的未冻水含量。结果表明:冻融过程的土样水分和土样中心温度随时间的变化均可分为三个比较明显的变化阶段,冻结过程和融化过程的变化特征略有不同,除了环境影响和探头自身因素外,我们将其归因于冻融过程的未冻水"滞后效应"。在快速冻融过程中,未冻水含量随温度的变化则表现出渐变的特征。通过对比三种典型未冻水含量的计算方法发现,通过拟合得到的方程计算结果的正确性较高。
[Abstract]:The characteristics of water and heat in the process of freezing and thawing play a decisive role in frost heaving and engineering stability. Taking Qinghai-Xizang silty clay as an example, In this paper, time-domain reflection method is used to measure and analyze the characteristics of water and heat changes of soil samples under different initial moisture content during freezing and thawing, and to compare the water and heat changes and their differences during freezing and thawing. Anderson et al. The calculation formula of unfrozen water with temperature as variable was put forward by Xu Eisu et al. And Michalowski. The unfrozen water content of soil samples with different initial moisture content at different temperatures was calculated respectively. The results show that the variation of soil moisture and soil central temperature during freezing and thawing process can be divided into three distinct stages. The variation characteristics of freezing and thawing processes are slightly different. In addition to the environmental effects and the probe's own factors, we attribute them to the "lag effect" of unfrozen water in the freeze-thaw process. By comparing the three typical calculation methods of unfrozen water content, it is found that the results obtained by fitting the equation are correct.
【作者单位】：长安大学公路学院;甘肃长达路业有限责任公司;甘肃海威公路勘察设计有限公司;
【基金】：国家自然科学基金(41272285)资助
【分类号】：P642.14

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