Uplift Behavior of Vertical Piles Embedded in Oil-Contaminated Sand

Abstract

There are several problems when dealing with oil-contaminated soil that affect environmental quality and alter the geotechnical properties of the soil. The influence of oil contamination on the uplift performance of model concrete piles embedded in sand at various densities is investigated. In this study, the model parameters are varied, namely, the thickness and diameter of the contaminated layer, type of oil contamination, pile surface roughness, and pile installation method. Contaminated-sand layers were prepared by mixing the sand with an oil content of 0–3% with respect to dry soil to match the field conditions. The results were then analyzed to study the effect of each parameter. To evaluate the scale effects, two sizes of model piles were tested, and the results were compared. This paper also discussed the effect of oil contamination on the relative ground movement around the pile surface. The results indicated that the uplift resistance was drastically reduced by oil contamination. The maximum reduction in uplift resistance and skin friction factor occurred at low contamination (oil content = 1%). The initial sand density and method of pile installation are significant factors affecting uplift capacity of piles embedded in oil-contaminated sand. The experimental results were used for the development of linear regression equations. These equations relate the uplift capacity ratio for piles embedded in contaminated sand to the aforementioned parameters.