冻土电阻率与其温度的关系研究

为研究冻土电阻率与温度的关系,采用自制电阻测量装置,对不同温度的砂土和黏土试样进行了电阻测试。结果表明,当温度大于0 ℃时,土的电阻率变化不大;当温度小于0 ℃时,土的电阻率随温度的下降而明显上升。出现这种现象的原因在于,当温度降低至0 ℃以下时,土中水分随温度的降低将逐渐部分或全部冻结为冰,而冰的电阻率大于液态水的电阻率。此外,冻土的电阻率还与土的类型有关,在干密度、含水量、温度均相同的条件下,砂土的电阻率大于黏土的电阻率。

Study on the Relationship Between Resistivity and Temperature of Frozen Soil

In order to study the relationship between resistivity and temperature of frozen soil, the resistance tests of sand and clay samples at different temperatures were carried out by self-made resistance measuring device. The results show that when the temperature is greater than 0 ℃, the resistivity of the soil changes little. However, when the temperature is less than 0 ℃, the resistivity of the soil will increase obviously with the decrease of temperature. The reason for this phenomenon is that when the temperature is reduced to 0 ℃, the water in the pore will gradually be frozen partially or completely. And the resistivity of the ice is greater than that of the liquid water. In addition, the electrical resistivity of frozen soil is related to its type. For example, the resistivity of frozen sand is greater than that of frozen clay at same dry density, water content and temperature.