Main Article Content
Today, the key role of soil in maintaining the foundations of structures and their stability (from structures such as residential buildings to earthen dams and huge concrete dams) is not hidden from any of the specialists and experts. This issue has caused attention and investigation in recent years by knowing the polluting factors and then eliminating or minimizing their reactions with soil compounds. The most important pollutants of urban soils are heavy metals and petroleum substances, which reduce the quality of the soil and, as a result, reduce its desired geotechnical function. These materials gradually accumulate in the soil due to their low mobility, and this accumulation leads to the disintegration of the soil granulation, reducing the bearing capacity and stability in the soil. The main purpose of this study, which was carried out by laboratory method, was to evaluate the geotechnical properties of soil contaminated with different percentages of petroleum substances and mixed with different percentages of cement and lime at the ages of 7 and 28 days. The results of the FESEM test for the S39 sample at the age of 28 days showed that this sample has a connected layered (sheet) structure and has assumed a more coherent and homogeneous state than other samples. Also, according to the images, the free space of the sample has been greatly reduced and thus the friction between the plates has increased. The small string compounds formed in this sample have caused the depth of the holes to be reduced favorably.