【摘要】 利用线热源热探针法对导土的导水率进行了测定。冻土中的传热过程中,除了由于水分迁移而引起热流发生外,还由于气、液、固三相的转变也将产生潜热。应用水热共轭输运理论分析这个过程,从而可以推算出冻土导水率。显然,在冰点附近时,潜热将对传热过程产生影响,从而使所得到的视导热率变得出奇地大。利用这种实测结果与冻土的实际导热率之间的差别,可以推算出冻土的导水率。所得结果与以往文献资料的结果相吻合。更多还原

【Abstract】 Present authors conducted experimental studies to estimate the hydraulic conductivity of partially frozen soils by means of needle probe method. The transport of heat in partially frozen soils occurs by conduction and by the convective transport of sensible and latent heat arising from the flow of water in gaseous, liquid and solid states. Theory describing the coupled flow of heat and water is used to determine an apparent thermal conductivity. Calculations suggerst that, at temperature close to melting point of ice in a frozen soil, the transport of latent heat may exceed the contribution of heat flux by conduction. Under these conditions, the apparent thermal conductivity becomes much greater than the bulk thermal conductivity. The differences between measured and bulk thermal conductivity of partially frozen soils derive the hydraulic conductivity of frozen soils. Estimated values of the hydraulic conductivity are consistent with previously reported ones.更多还原