Effects of Lead and Gasoline Contamination on Geotechnical Properties of Clayey Soils

Various laboratory tests were carried out to study the effects of lead and gasoline on the geotechnical properties of three kinds of contaminated soil. This paper addresses soils contaminated with lead, gasoline, and lead-gasoline. This work aimed to investigate the critical alterations in geotechnical properties of an artificial soil (MDD: 17.6 kN/m(3)) due to these contaminants ' simultaneous application. For this purpose, soil samples were prepared with several lead contents (1000, 2000, 5000, 10000, 20000 ppm) and different gasoline contamination percentages (the 3%, 6% and 9% weight of dried soil) with the 4 days contamination duration. The tests conducted were: compaction, permeability, direct shear test, unconfined compressive strength, X-ray diffraction, and SEM analysis. The results indicated increment in maximum dry density and internal friction angle with the increase in the amount of lead and gasoline in all types of samples. The growth in maximum dry density was higher with gasoline than lead contamination. Also, by increasing lead content in contaminated samples the values of cohesion and hydraulic conductivity increase while a reverse trend was observed with the climb in gasoline content. Furthermore, Lead-gasoline contaminated samples show a peak behavior for both unconfined compressive strength and failure strain by an increase in pollution content.