عنوان مقاله [English]
The presence of oil in the soil media, by changing the interaction between soil particles, reduces the shear strength of the soil compared with clean soil. Finally, oil pollution, reduces permeability, internal friction angle and bearing capacity and increases volumetric strain and the resulting settlement of the structure. On the other hand, most of the foundation analysis methods require the use of subgrade reaction modules as a basic parameter to assess elastic situation of the subgrade and determination of the stiffness and load-deformation behavior of the soil. It should be noted that, subgrade reaction modulus is obtained mainly through field plate loading testing. In this study, using physical modeling with plate loading, deformation behavior and stiffness of oil-contaminated sand and reaction modulus for the different percentages of oil contamination will be reviewed. The results can present a more appropriate estimate of the amount of elastic settlement of the structures rested on the contaminated soils, also refine the amount of footing's flexibility on this group of soils. The most effective parameters on the soils stiffness in this field include the soil classification, relative density, type of contamination and the amount of contamination in the soil. These variables can be effective in the process of the possible changes of stiffness and soil reaction modulus. Gas oil, crude oil and kerosene have been used as contamination materials. These liquids have been added into the sand in three different percent rates, 2, 4 and 6. The sand has been compacted in three different situations; loose, medium and dense. Based on this research, oil contamination causes substantial decrease in soil stiffness and more greasy oil contamination is even more effective in reducing the soil subgrade reaction. In addition, dense soils stiffness is less sensitive to oil contamination effects. These results can be used for investigating the sites in which there is a possibility of oil leakage to layers of the land. Results have been presented in the form of empirical equations.