| With the rapid development of the world economy, the utilization of energy hasbecome a necessity for the demands of economic development. As an importantenergy and industrial raw material, petroleum is a very important material basis andlink for economic development. But with the development and utilization of oil, it notonly brings economic benefits but also serious environmental problems. There areseveral potential sources of oil leakage to surrounding ecosystem are through damagepipeline, tanker accidents, discharges from coastal facilities and natural seepage. Oilpollution’ scope not only involves the range of soil, groundwater, ocean, and even theair. The present study for oil-contaminated soil is relatively less, and it did not form asystem research. Based on the effective treatment and rational utilization of theoil-contaminated soil, it is imminent to take a systemic study for the polluted soil,which has great significance for the engineering construction.Oil pollution has become a world problem, in order to deal with the polluted soilreasonably and make full use of the resources, it can be considered to use the pollutedsoil in many geotechnical works e.g., embankment, backfill, parking lot. Thisapproach not only reduces the cost but also makes full use the resources. While thereare more factors need to be considered for contaminated soil is quite different fromuncontaminated. Firstly, it is necessary to study the physical and mechanicalproperties of the contaminated soil, and then the properties of the solidified soil, thusimproving the quality of polluted soil in construction.The soil used in this paper is silty clay, derived from Changchun area. Choose thediesel oil as the present petroleum. The preparation of soil samples with differentpollution degree is through artificial method (oil content were0%，4%,8%,12%and16%). The study aimed at the engineering properties of the diesel contaminated soil, in order to take advantage of the polluted soil after solidification to recycle theresources. The hydrocarbon contamination will greatly change the geotechnicalproperties of the diesel-contaminated soil. This paper mainly focuses on the indoorexperimental study of the engineering properties of the soils from two aspects. Thephysical properties mainly include soil particle size distribution, specific gravity,Atterberg limits; while the mechanical properties include soil compaction,compressibility, shear performance and so on. In view of the influence of diesel oil onthe engineering properties of the soil, propose a method to solidify the soil by cement,and then carried out the strength test to verify the feasibility. Finally, the scanningelectron microscopy (SEM) and X ray diffraction (XRD) were took to test the soildisposed with different methods. This paper from the view of microstructure andmineral composition to explain the weaken role of the diesel for the soil and thereinforcement effect of the cement.The study finds that the mineral compositions of the silty clay in Changchun areachanged under the action of diesel oil, such as the reducing of the alkali feldspar. Theconnection between the soil particles is weakened by the dissolution of the minerals,thus large particles change into small ones, which can be observed from the SEMmicrograph. This explains the mechanism of the effect on the soil’s engineeringproperties of the diesel oil from a microscopic view. The contaminated soil can beconsidered to be used for engineering construction after solidification for its strengthcan be enhanced obviously. The hydration reaction will immediately occurs whencement mixed with the contaminated soil, thus the fine particles can be wrapped bythe hydration products, finally get together into larger clumps. From the SEM imagescan clearly see that the solidified soil basically does not exist single particlescompared with the undisturbed soil, but all condenses into blocks to improve the soilstrength. This paper also carries out the quantitative evaluation for the properties ofthe diesel-contaminated soil in Changchun area and the cement solidification of thepolluted soil; all these will provide a theoretical basis for the mechanism and thereasonable utilization of the contaminated soil. |
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