Abstract: The thermal parameters of loess are the important indexes in the study of loess disaster and thermal calculation, while the water content and dry density have a certain influence on the parameters. Thermal parameters of loess samples with different dry densities and different moisture contents are tested in normal temperature by using thermal constant analyzer Test Protocol Hot Disk TPS 2500S to explore the variations of thermal parameters of loess which are influenced by moisture contents and dry densities. The study reveals that: with a constant moisture content of the loess samples, the higher the dry density is, the greater the thermal conductivity, the specific heat capacity and the thermal diffusivity are. The thermal conductivity and specific heat capacity of loess samples increase linearly with the increase of moisture contents. When the moisture content is low, the thermal diffusivity increases with the increase of moisture content. When a certain moisture content is reached, the thermal diffusivity decreases with the increase of the moisture content. The thermal diffusivity tends to be stabilized with the continual increase of the moisture content of loess samples. The impact on the thermal parameters by the moisture content of loess is greater than that by the dry density of loess. In thermal engineering calculation, thermal parameters can be dynamically selected in accordance with soil moisture.

Key words: loess, thermal parameter, moisture content, dry density, thermal conductivity, specific heat capacity, thermal diffusivity