土壤热导率的影响因素实验研究

EXPERIMENTAL STUDY OF INFLUENCE FACTORS OF SOIL THERMAL CONDUCTIVITY

采用热针法测定室内不同条件下红粘土、粉土和细砂的热导率，着重分析含水率、干密度和土壤质地对土壤热导率的影响规律及机理。研究结果表明：1）相同干密度情况下，粉土和细砂两者的热导率均随含水率的增加而单调线性递增，红粘土的热导率则随含水率的增加而呈现出分段递增的趋势；2）含水率对热导率的影响主要归结为土样中液相（水）热导率、结合水膜（“液桥”效应）2个主要因素，而“液桥”效应对红粘土的热导率影响显著；3）相同含水率情况下，3种土样的热导率均随干密度的增加而递增，具有较好的线性关系；4）土壤质地（细颗粒和石英含量）对土样热导率具有显著影响。

The thermal conductivities of red the heat probe method. Then the influence clay, silt and fine sand under different indoor conditions were measured by law and mechanism of water content, dry density and soil texture on soil thermal conductivity were analyzed emphatically. The research results showed that 1）Under the same dry density, the thermal conductivities of both silt and fine sand increase monotonically and linearly with the increase of water content, the thermal conductivity of red clay shows piecewise increase trend with the increase of water content. 2）The influence of water content on thermal conductivity is mainly attributed to the two main factors of liquid phase （water） thermal conductivity and absorbed water film （＂liquid bridge＂ effect） in soil samples, and the effect of ＂liquid bridge＂ effect on the thermal conductivity of red clay is significant. 3） It is also found that under same water content, the thermal conductivities of three kinds of soil samples increase with the increase of dry density, and have a good linear relationship. 4） the soil texture （the contents of fine particle and quartz） has a significant influence on the soil thermal conductivity.