Triaxial shear behaviour of oil contaminated clays

Abstract

This study is focused on investigating the geotechnical behaviour of oil-contaminated clays through a series of laboratory experiments including standard compaction, uniaxial and triaxial compression tests. The contaminated samples were prepared with addition of gasoil and kerosene in the amount of 3, 6 and 9% in two different series. The first series includes kerosene contaminated kaolinite which is compacted at optimum moisture content of the clean soil, whereas the second series contains kaolinite and bentonite soils with optimum moisture content of already contaminated batches. The results show an improvement in compaction characteristics of kaolinite and bentonite specimens upon the addition of contamination. Furthermore, the triaxial shear strength of the first set of samples undergoes a decrease in parallel with the addition of kerosene which is more significant at higher confinement levels. On the other hand, the uniaxial and shear strength values of second series increases when mixed with contamination which is more notable in presence of gasoil compared to kerosene. Finally, the 9% contaminated kaolinite specimens do not follow the same pattern of changes in strength similar to 3 and 6% contamination due to the different structure of 9% contaminated clay observed in scanning electron micrograph photos.

Keywords:

• contaminated clay
• shear strength
• triaxial test
• uniaxial test
• SEM