击实膨胀土的电阻率特性试验研究

Electrical Resistivity Characteristics of Compacted Expansive Soil

针对电阻率与膨胀土特征的关系研究较少的现状,研究了击实膨胀土的电阻率特性与利用电阻率法评价膨胀土胀缩变形的可行性及评价方法。在不同的击实条件下制备膨胀土击实试样,利用ESEU-1型土的电阻率测试仪,采用二相电极在低频交流电作用下测试土的电阻率。具体研究了含水量、孔隙液电阻率、孔隙率、温度以及击实功等对击实膨胀土电阻率的影响特征,以及击实膨胀土的膨胀量、膨胀力以及线缩率与电阻率的关系,探讨了利用土的电阻率法评价膨胀土胀缩特性的方法。结果表明:击实膨胀土的电阻率随含水量、温度、孔隙率的增加而减小,而击实土的膨胀率、膨胀力及线缩率随电阻率的增大而增大。因此,该方法可有效预测现场膨胀土特性及其他工程性质。

The electrical resistivity properlies of compacted soils have been presented by many literatures, but the relationships between electrical resistivity and swell-shrinkage properlies of compacted expansive soils have not been received sufficient attention.The electrical resistivity characteristics of compacted expansive soils and the methods to evaluate the swelling-shrinkage properlies of compaeted expansive soils using electrical resistivity measurements are studied. Soil electrical resistivity was measured with the ESEU-I resistivity equipment and a two electrode cell applying 50 Hz alternation current （AC） .The effects of water content, the resistivity of pore fluid, temperature, porosity and compaction on the electrical resistivity and the relationship between the swell- shrinkage properlies and electrical resistivity of compacted expansive soils are, discussed. The test results show that the electrical resistivity decreased with the increase of water content, temperature or porosity of compacted expansive soils, but its swelling ratio, swelling pressure and linear shrinkage rate increased with the increase of the electrical resistivity.