Effect of Crude Oil Pollution on Some Geotechnical Properties of Disturbed Sandy Soil

Abstract

Recently, the effects of soil pollution with crude oil have received much attention from many researchers. Most of the results showed contradictions in their results because of adding crude oil to the soil. Some of the results showed an increase in the maximum dry density while other results indicated a decrease as well as for the shear resistance. The present study seeks further research to evaluate the physical and mechanical properties of loose sandy soils contaminated with crude oil obtained from the Nalut region in southwestern Libya. The soil samples used in this research were classified according to the Unified Soil Classification System (USCS) as poor graded sandy soil (SP.) And were classified (A-3) according to the American Association of Highway and Transportation Officials for Classifying Soil System (AASHTO). The contaminated material is crude oil from Abu Al-Tifl field located in Gallo city. The soil was polluted in a laboratory by manually mixing the soil with the pollutant material in percentages (10, 7, 4) of the dry soil weight after the soil was well mixed with the pollutant and after confirming the uniformity of the distribution The pollutant was in the soil and left for three days in closed containers to study the effect of crude oil on the physical and mechanical properties of the soil by conducting conventional tests to measure these properties and through the results of laboratory tests showed that crude oil has a great effect on some properties and little effect on other properties. As the increase in the pollutant percentage in the soil led to a slight effect on the specific gravity, while there is a significant effect on the permeability coefficient as it decreased with the increase in the percentage of pollutant, the optimum water content also decreased and the maximum dry density increased with the increase in the percentage of pollutant, while the value of the California Bearing Ratio (CBR) increased at 4% and then starts to decrease as the crude oil increases.