机油污染膨胀土基本工程特性的室内试验

Fundamental engineering properties of expansive soil polluted by oil in laboratory

在室内人工制备了4种不同机油含量的污染膨胀土,对其液限、塑限、膨胀特性、抗剪强度等基本物理性质进行了试验研究。结果表明:适量的机油会增加膨胀土的液限,但机油含量达到一定值后,土样的液限先减小,后趋于稳定值;污染膨胀土的塑限都小于原状土,且随机油含量的增加而减小,而塑限指数均大于原状土,且随机油含量变化不大;机油含量较少时,机油对膨胀土的膨胀起促进作用,膨胀土的自由膨胀率和无荷膨胀率均增加,机油含量为8%时达到峰值;随着机油含量的增加,机油对膨胀土的破坏作用加强,膨胀土的膨胀作用减小;机油对膨胀土的结构有破坏作用,机油污染导致膨胀土的黏聚力、内摩擦角及强度均会变小。

The expansive soils contaminated by 4 different concentrations of oil in laboratory are used to study the basic properties of liquid limit, plastic limit, expansion characteristics and shear strength. The results show that： for the expansive soils contaminated by oil, the appropriate amount of oil will increase the liquid limit of the expansive soil but the liquid limit of the oil content of the oil can be reduced to a stable value; the plastic limit is less than the original soil and the increase of the random oil content decreases, while the plastic limit index is larger than the original soil and the random oil content changes little; when the concentration of oil is low, the oil can promote the expansion of the expansive soil, and the oil concentration peaked at 8%; with the increase of the oil concentration, the damage of the oil to the expansive soil is strengthened, and the expansion of the expansive soil decreases; the prediction model of the change relationship between load-free swelling of polluted soils and time is established; the addition of oil causes the mineral composition and composition of the expansive soil to be destroyed, the cohesion, the internal friction angle and intensity of the expansive soil and are reduced.