Numerical analysis of the effect of crude oil pollution on the slope stability of clay

The presence of petroleum products (crude oil pollutions) in clay with low limit liquid (CL) due to physical and chemical processes causes changes in the stress-strain curve, wedge rupture, plastic zone and, strain energy compared to unpolluted soil. These changes often reduce the safety factor against failure, increase the plastic zone, and Decreased soil slope stability. So far, the effect of crude oil pollution on soil shear strength parameters has been tested by direct shear test and the modulus of subgrade reaction has been tested by plate loading test for different types of clay and sandy soils. In this study, the effect of changes in crude oil pollution in the range of 0 to 16% (0-4%-8%-12%-16%) on clay soil slope stability has been done by numerical modeling of finite element method in ABAQUS software. The height of the clay slopes is 10 m, 13 m and, 16 m and, the slope angle of the slope is 53 degrees. The results of this study show that increasing crude oil pollution reduces slope stability. It is predicted that with the increase of crude oil pollution in the range of 0 to 16%, the safety factor of clay slope stability will decrease by 72%. Also, increasing only 4% of crude oil pollution in clay soil slope (12% to 16% of crude oil pollution), causes a 2 to 3 times increase in horizontal displacement and a 3 to 4 times increase in vertical displacement.