粉土热导率与含水量关系的实验研究

LABORATORY TESTS FOR PRECISE RELATIONSHIP BETWEEN THERMAL CONDUCTIVITY AND MOISTURE CONTENT OF SILT SOIL

目前报道的不少实验成果,在得出粉土热物性指标和某一因素的关系时,并未保持其他影响因素固定不变,因而只能说明粉土热物性指标随影响因素的定性变化趋势。要建立热物性指标与影响因素间的确定性关系和推算公式,需要更为严格的实验,即研究某一影响因素时保持其他因素不变。通过一系列实验,对粉土试样的热导率进行研究,在排除孔隙比、干密度、土样成分等影响因素的情况下,独立分析了粉土的热导率与含水量间的关系。实验结果表明粉土的热导率随含水量的增大而增大,其变化规律与砂土一致,都符合对数变化规律,且整个变化过程可分为两个阶段。同时还分析了粉土的内在传热机制,有效描述和解释粉土热导率随含水量的变化规律。分析结果表明用对数形式来描述粉土热导率与含水量之间的关系是正确的。

Currently, a lot of tests have been done to study the change of thermal properties ot silt sods with a tactor. However, in the studies on the effect of a factor, other influencing parameters have not been kept unchanged. In order to build the precise relationship between thermal properties and the influencing factors of silt soils, more strict experiments are required. In addition, few tests on silt＇s thermal properties have been reported yet. In the present studies, a series of laboratory tests have been carried out to examine the relation between thermal conductivity and moisture content of the silt soils. In these tests, the effects of moisture content were examined individually, while the other factors（such as dry density and void ratio） are kept constant. It is indicated that the thermal conductivity increases with the increase in moisture content, and follows the logarithmic law which is consistent with sand. Subsequently, comparisons between present studies and other resuhs conducted. Finally, the heat transfer mechanism of the silt soil is studied to reported in the previous studies were explain the present results.