Briefing: Liquefaction potential of oil-contaminated silty sands

Oil spills may occur during exploitation and transportation or can result from accidents in oil pipelines or tanks. Such spills may cause environmental and ecological problems than can lead to changes in the mechanical properties of the affected soil. A series of cyclic triaxial tests was conducted to evaluate the effects of oil contamination on the liquefaction potential of sands and silty sands. The specimens were prepared by adding silt to Firouzkooh sand at ratios of 15, 30, 35 and 40%, mixed with crude oil (contents of 4, 8 and 12%). The results indicated that the liquefaction potential increases with an increase in silt content until a silt content of 35%, when the liquefaction potential starts to decrease. It was also found that, up to 30% silt content, the silt controls the liquefaction behaviour. Furthermore, when oil contamination exceeds 8%, the liquefaction resistance starts to decline.