氯化钠的掺入对冻土基本热学性质的影响

Study on the General Thermal Parameters of the Frozen NaCl Soil

应用稳定态的比较法，测定了不同总含水量、不同土中溶液浓度的冻结兰州砂土、兰州黄土的导热系数，同时应用量热法测定了土骨架和纯氯化钠在同一负温下的比热，并据此计算了土的导温系数。结果显示，在同一负温下各种土质的比热均随含盐量的增加而增大，兰州砂土的导热系数和导温系数随含盐量的增大而降低，而兰州黄土的这两个参数随含盐量从零开始增加，首先增大，在土中溶液初始浓度约为５％时，达到最大值，接着逐渐减小。

Using the steady comparing method，we measured the thermal conductivity of the frozen Lanzhou sand and Lanzhou loess with various salt content and water con-tent．We also measured the values of speciflc heat of the soil grain and pure sodium chloride and calculated the thermal diffusivities．The data show that the speciflc heat of soils increases with the increasing of salt content．The thermal conductivity and thermal diffusivity of Lanzhou sand go down with the increasing of salt content atthe same temperature. For Lanzhou loess hOwever，the two parameters go up at firstand then go down with the increasing of saIt content，there is a maximum of theparameters corresponding to the concentration about 5％ of NaCl solution in soil.