Bearing capacity of unsaturated oil-contaminated sand

Onshore and offshore oil spills contaminate soil. In addition to environmen tal concerns about ground water pollution and other possible effects, the g eotechnical properties of the contaminated soil such as the shear strength and the hydraulic conductivity are also altered. This paper presents the re sults of research to evaluate the variation of the shear strength of a sand contaminated by 3 different types of oil with varying kinematic viscositie s and thus the ultimate bearing capacity of shallow foundations. The result s of the tests reported here relate to only I type of sand and 3 types of o il. The oil contents varied from zero to 6%. Results of direct shear tests for determining the soil friction angles are given. Additionally presented are laboratory model test results to determine the ultimate bearing capacit y of a surface strip foundation supported by oil-contaminated sand. Based o n these test results, the effect of oil contamination in drastically reduci ng the bearing capacity is discussed.