Analyzing Physical-Mechanical and Hydrophysical Properties of Sandy Soils Exposed to Long-Term Hydrocarbon Contamination

This paper aims to investigate the issue of sandy soil contamination by oil hydrocarbons. Laboratory procedures used to study conditionally pure and contaminated sands include grain-size measurements and evaluation of physical-mechanical and hydrophysical properties. The results of the analysis of sand samples using visual and microscopic studies and sieve analysis show that, unlike in conditionally pure sands, in contaminated samples, the surface of mineral particles is covered by hydrocarbon film. The presence of the latter enables micro- and macroaggregates to be formed. Studies of the physical and hydrophysical properties of sands using a technique with pre-weighed glass containers, as well as a filtering device, SPETSGEO pipes, showed that, in comparison with conditionally pure samples, contaminated specimens of sandy soils have lower densities and higher permeabilities and water yields. Testing the mechanical properties of contaminated sands on the GPP-30 direct shear apparatus using the consolidated dried shear strength method revealed an increase in the angle of internal friction with a decrease in specific adhesion compared to conditionally clean sands.

Automated summary

This paper investigates the issue of sandy soil contamination by oil hydrocarbons. The laboratory procedures used involve grain-size measurements and evaluation of physical-mechanical and hydrophysical properties. The results show that contaminated sand samples have a hydrocarbon film covering the surface of mineral particles, leading to the formation of micro- and macroaggregates. Additionally, contaminated sandy soils exhibit lower densities, higher permeabilities, and water yields compared to conditionally pure samples. Mechanical testing indicates an increase in the angle of internal friction and a decrease in specific adhesion for contaminated sands.