刘鹏, 阎长虹, 徐杨, et al. Laboratory Research on Influence Factors of Thermal Conductivity for Xiashu Loess in the Area of Nanjing[J]. 2016, 36(5): 847-852. DOI: 10.13409/j.cnki.jdpme.2016.05.023.
Laboratory Research on Influence Factors of Thermal Conductivity for Xiashu Loess in the Area of Nanjing
摘要
岩土体热物理性质是当前岩土工程领域的一个重要研究课题
其关键在于岩土体导热系数的测试。使用日本EKO公司HC-110型热导仪
应用稳态法对南京地区典型下蜀土的击实重塑样进行导热系数测试
分析含水率、密度及试验温度对土体导热系数的影响
从土颗粒间、土颗粒与水分子间的接触方式对不同物理指标下土的导热系数的影响机制进行机理分析
结果表明:含水量一定
试样密度越大
土颗粒之间接触面积越大
土体热交换能力越强
导热系数越大;试样密度一定
温度升高时水分子活动能力加剧
导热系数随温度升高而增大
含水量大于16.6%时
导热系数随温度变化趋于平缓
温度大于50℃时导热系数有变小的趋势;试验温度一定
含水量小于20%时导热系数增大明显
含水量超过20%时试验值变化范围较小且有曲线重合现象。
Abstract
Thermal physical properties of the soil and rock mass have become an important research branch in the field of geotechnical engineering.The key measuring method is laboratory thermal conductivity test.Applying the principles of steady method
this paper measures the thermal conductivities of the compact remolded samples of Xiashu loess in Nanjing
with the instrument of HC-110 thermal conductivity meter(EKO Inc.
Japan).The factors that have influences on thermal conductivity are analyzed
including soil density
water content and temperature.The analysis of the mechanism of the experimental results and the influence of different physical parameters are made on the basis of the contact modes among soil matrix
and among soil particles and water molecules.It is concluded that under a certain water content
the higher the sample density
the bigger the contact area between soil and the stronger soil heat exchange capacity is
and an increasing value of thermal conductivity will be caused.In contrast
under a constant sample density
the reactivity of water molecules rises and the thermal conductivity improves as the temperature increases.When the water content is higher than 16.6%
the thermal conductivity has a plateau-like variation with the temperature change.When the temperature is higher than 50℃
the thermal conductivity has a smaller tendency.Under a certain temperature
the thermal conductivity increases significantly when the water content is less than 20%
and the variation of the thermal conductivity has a less range and presents a curve coincidence phenomenon when the water content is higher than 20%.
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