掺石灰黏土电阻率试验研究

利用4电极电阻率测量装置,在室内对各种灰土样的电阻率进行测试对比研究,揭示了不同因素如灰土比、含水率、饱和度、土的结构和土粒粒径等对灰土样电阻率的影响。在不同含水率(15%、20%、25%和30%)条件下,素土及其与不同石灰掺量(1:10、1:15和1:30)的混合,通过轻型击实试验后,测量其横向及竖向断面上的电阻率,研究电阻率与不同石灰配比击实土样的物理力学性质之间的关系。实验结果表明,当含水率在15%～20%之间时,较小的含水率增量引起混合土样电阻率的大幅度下降;当含水率约达到20%后,其电阻率随含水率的继续增加而减小的幅度很小;在15%含水率时,掺灰土电阻率比素土样高;在30%含水率时,其电阻率低于素土样,而且掺量越大,电阻率越低;由于击实导致土体颗粒的结构重新排列,电阻率在横向上大于竖向;电阻率随着无侧限抗压强度的增加而增加,在电阻率大于50Ω·m时,电阻率随无侧限抗压强度的增加而减小;饱和度、干密度与电阻率呈负指数变化规律,孔隙率、孔隙比与电阻率呈指数变化规律;含水率对于电阻率的影响较为敏感。

Electrical resistivity measurement for lime-stabilized silt soil

The electrical resistivity of various lime-soil samples are studied indoor with four electrode resistivity measurement, the effects of different factors such as lime-soil ratio, water content, water saturation, soil structure and particle size on lime-soil samples were revealed. Under different water contents (about 15 %, 20 %, 25 % and 30 %), soil were mixed with lime at different lime-soil ratios (about pure soil, 1:10, 1:15 and 1:30). With light compaction test, the traverse and vertical resistivity of mixed soil samples were measured and the relationships between resistivity and physical properties of mixed soil samples with different lime-soil ratios are studied too. The electrical resistivity of mixed soil samples drops greatly with 15 %-20 % water contents, increases with about 20 % water content; and the resistivity reduces as the water content increased continuously. The electrical resistivity of lime-mixed soil sample larger than electrical resistivity of pure soil with 15 % water content, but the resistivity of lime-mixed soil samples is smaller than pure soil samples with 30 % water content. The resistivity is more lower as the lime mixing amount is larger. The electrical resistivity at transverse section is larger than at vertical section. The electrical resistivity increases from 0 to 50 ??m as the unconfined compression strength increases. When the electrical resistivity larger than 50 ??m, the resistivity decreases as unconfined compression strength increases. The relationship between water saturation and dry density is negative exponent; the relationship between porosity and void ratio is exponent reverse to the dry density. The resistivity is sensitive to the water content.