饱和水土壤电阻率温度特性及对直流接地极温升的影响

针对土壤含水量较高的区域直流接地极温升特性不明的问题，对不同类型的土壤进行了水饱和温升电阻率测量。并在此基础上建立了饱和水土壤接地极的电热耦合有限元模型。通过算例与未考虑含水饱和土壤电阻率温升效应的仿真结果进行对比，发现其温升结果明显偏低，随着电流注入时间的增加，电极温升曲线的饱和度变得更加明显。最后进行了饱和水土壤垂直电极的温升试验，验证了耦合模型的可靠性。实验和仿真结果表明，考虑饱和水土壤温度特性可使计算误差降低31.84%。因此，结合饱和水土壤电阻率温度特性对接地极进行温升计算，能更大程度的保证计算的准确性。

Temperature Characteristics of Water-saturated Soil Resistivity and its Influence on DC Grounding Electrode Temperature Rise

Aiming at the problem that the temperature rise characteristics of DC grounding electrodes in areas with high soil water content are unknown， this paper measures the water saturation temperature rise resistivity of different types of soils. On this basis， an electro-thermal coupled finite element model of the grounding electrode in water-saturated soil is established. A numerical example is used to compare the simulation results without considering the temperature rise effect of water-saturated soil resistivity， it is found that the temperature rise result is obviously low. With the increase of current injection time， the saturation of the electrode temperature rise curve becomes more obvious. Finally， the temperature rise test of the vertical electrode in the water-saturated soil is carried out to verify the reliability of the coupled model. The experiment and simulation results show that the calculation error can be reduced by 31.84% by considering the soil temperature characteristics of the saturated water. Therefore， calculating the temperature rise of the grounding electrode in combination with the temperature characteristics of the soil resistivity of the saturated water can ensure the accuracy of the calculation to a greater extent.