Long Term Ageing Effect on Physical and Shear Strength Characteristics of Oil Contaminated Sandy Soils of Al-Ahmadi Field in Kuwait

Abstract

Serious environmental damage was caused to Kuwait when more than 600 oil wells were set alight following the 1991 Gulf War, leading to hydrocarbon contamination and a series of ‘oil lakes’ being created in the desert. The effects of these highly damaging actions are still detectable today, 27 years later. The main contribution of this paper is that the effects on the behavior of physical and shear strength properties of the Al-Ahmadi field sand brought about via the long-term ageing influence of hydrocarbon contamination will be explored, using the methodology of comparing contaminated and non-contaminated soil samples. For the purpose of this paper, nine samples, from more than 28 years’ oil contaminated site, were subject to both physical and shear strength tests alongside hydrocarbon analysis using Gas Chromatograph Mass Spectrometer (GC-MS) testing. The results of these tests showed a notable increase in both the mean values of fines particles (from 7.8% to 11.8%) and of gravel particles (from 5.8% to 27.8%). These results clearly illustrate that the overall effect of the change in soil gradation was a poorer one. A reduction in strength was also observed in these tests, which possibly related to accumulation of particles within the soil layer leading to poorer grain size and to ageing effect that increase asphalting lead to weak bonding between particles.