YE Wan-jun, DONG Xi-hao, YANG Geng-she, et al. Effect of moisture content and dry density on thermal parameters of loess[J]. 2017, 38(3): 656-662.
DOI:
YE Wan-jun, DONG Xi-hao, YANG Geng-she, et al. Effect of moisture content and dry density on thermal parameters of loess[J]. 2017, 38(3): 656-662.DOI: 10.16285/j.rsm.2017.03.006.
Effect of moisture content and dry density on thermal parameters of loess
黄土的热参数是黄土灾害成因机制研究及热工计算中的重要指标,而含水率和干密度对黄土的热参数具有一定的影响。对不同含水率、不同干密度黄土试样,采用Test Protocol Hot Disk TPS 2500S型热常数分析仪,在常温下开展热参数试验,探讨黄土热参数随含水率及干密度的变化规律。研究结果表明:黄土试样含水率一定时,干密度越大,其导热系数、比热容及热扩散系数也越大;黄土试样的导热系数和比热容随含水率的增大基本呈线性规律增大;当含水率较低时,热扩散系数随含水率的增大而增大;当达到一定含水率时,热扩散系数随含水率的增大而减小;继续增大含水率,热扩散系数趋于稳定。含水率对黄土热参数的影响程度大于干密度对其热参数的影响程度。在热工计算中,可根据土体含水率和干密度动态地选择热参数。
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.