Behaviour of strip footing on oil-contaminated sand slope

This paper presents an experimental and theoretical programme aimed at promoting a greater understanding of the behaviour of strip footing on oil-contaminated sand slope. Contaminated sand layers were prepared by mixing sand with an oil content of 0–3% by weight of dried sand. A broad series of conditions, including uncontaminated cases, was tested by varying parameters such as the thickness of the contaminated sand layer, the type of oil contamination, the slope angle and the edge distance of the footing relative to the slope crest. A plane-strain elastoplastic theoretical model using finite-element analyses was additionally performed to supplement the results of the model tests. The results indicate that the ultimate bearing capacity of strip footings on the contaminated sloping ground can be drastically decreased with increasing the thickness of the contaminated sand layer and the slope angle. To design a footing on oil-contaminated sand slope, it would be necessary to reduce the value of the bearing capacity factor N_γ according to the type and percentage of the contaminated oil. The investigation also provides knowledge to revise the foundation design of the existing structures subjected to contamination.