非饱和黄土物理力学参数与导热系数关系的研究

Study on the relationship between physical and mechanical parameters and thermal conductivity of unsaturated loess

为了研究黄土导热性能与其物理力学参数之间的关系,文章对宁东黄土进行了导热系数、标准贯入试验及含水率、密度等参数的测试,对测得的数据进行了拟合及相关性分析,讨论了不同参数与导热系数的关系。试验结果表明,非饱和黄土中的气体和孔径是影响导热系数的关键。土越密实,含水率越高,土中气体的体积越小,导热系数越大;孔径越小,导热系数越大。非饱和黄土强度越高,其导热性能不一定越好。含水率、密度、干密度、饱和自重压力、液性指数、粘聚力、压缩系数和标准贯入等指标与导热系数有显著的相关性,可以很好的评价黄土的导热性能。

In order to study the relationship between the thermal conductivity of loess and its physical mechanical parameters,we test the thermal conductivity,standard penetration test and density of loess in Ningdong area,and the measured data is simulated. The correlation analysis of relationship between different parameters and thermal conductivity are discussed. The experimental results show that moisture content,density,dry density,saturated self-weight pressure,liquid index, cohesion, and standard penetration have significant correlation with thermal conductivity, which can evaluate the thermal conductivity of loess approximately. The gas and pore size in unsaturated loess are the critical factors to the thermal conductivity. The denser soil,the higher moisture content,the smaller volume of gas in the soil,and there is the greater thermal conductivity. The smaller aperture,and there is the greater thermal conductivity. With the increasing of soil strength,its thermal conductivity is not necessarily good.