Effect of crude oil spillage on engineering properties of tropical residual soil

Oil exploration in Nigeria causes serious environmental degradation. Little is known about the effects of crude oil spillage on soils found in northern Nigeria where oil exploration started less than two years ago (2018). This research is a comparative analysis of the effect of crude oil on contaminated and uncontaminated soil typically found in northern Nigeria. Five Trial pits were dug at Bayero University Kano, two of the trial pits were filled with 20 litres of crude oil while the remaining three trial pits were left uncontaminated and used as control. The crude oil was allowed to infiltrate into the soil for about six (6) weeks before samples of soil were obtained for laboratory analysis. Maximum dry density (MDD), natural moisture content, California Bearing Ratio CBR value, cohesion, and Atterberg limits test were used to analyse the soils. Average natural moisture content was found to be 21 % for uncontaminated soil and 8% for contaminated soil, the MDD value was 1.80 g/cm³ for uncontaminated soil and 1.67g/cm³ for contaminated soil, the CBR changes from 25 % to 6 % while cohesion decreased by 48 % for the contaminated soil respectively. The results show negative consequences for road and building constructions in the simulated crude oil contaminated area.