Document Type : Research Article
Authors
1
Department of Civil Engineering, Faculty of Engineering, Razi University of Kermanshah
2
West Hemat highway,Kabiri Tame Chamran street,Aghaghia, P.4
Abstract
The issue of soil contamination with petroleum compounds in Iran, a country renowned for its abundant oil reservoirs, presents a formidable challenge. The infiltration of oil pollutants in oil exploration sites results in soil contamination with hydrocarbons. The development of construction projects in oil-rich areas and the leakage of oil pollutants, the implementation of such projects requires sufficient knowledge of the geotechnical characteristics of oil contaminated soils. The estimation of soil dynamic parameters has a decisive role in the analysis of the structures and stress-strain behavior of soils. In this research, clay soil with highly plastic properties and different amounts (0, 2, 4, 6, 8, 10, 12, 14%) of Kermanshah refinery crude oil were used as hydrocarbon pollutants. The analysis of XRD, FESEM, EDAX and BET were used to characterize the mineral and morphology of the soil, and the results showed that the clay soil mineral was of kaolinite type. The results of the Atterberg limit test on clean and contaminated soil samples showed that with increasing pollution, the plastic limit and liquid limit decrease, and the plastic index decreases up to 10% of pollution and then increases. According on the compaction test, porosity ratio and the optimum moisture content of clean and contaminated samples obtained. The results showed that the maximum dry density of soil is equal to 1.61 gr/cm3, which is created in the clay sample with 12% contamination. Shear wave velocity and maximum shear modulus (Gmax) of clean and contaminated clay samples prepared with maximum dry density, in the range of 100 to 400 KPa confining pressure and frequency of 5 to 20 kHz, were measured by a bender element device. The graph of changes in shear wave velocity according to the porosity ratio for clay with different percentages of oil contamination showed that, with the increase of porosity, the shear wave velocity has decreasing trend. The results showed that the highest shear wave velocity and maximum shear modulus were observed in clay with 12% contamination in condition of 300 KPa confining pressure and 20 kHz frequency obtained 320 m/s and 512 MPa, respectively, Also with the increase of confining pressure and frequency, the shear wave velocity increases.
Keywords
Main Subjects
)