Effects of contamination with gasoline on engineering properties of fine-grained silty soils with an emphasis on the duration of exposure

Abstract

Leaking tanks may lead to severe contamination of their surrounding soil. The geotechnical behavior of the soil varies with the physicochemical processes that occur between the contaminant and the soil. In this respect, studying the geochemical properties of gasoline-contaminated soils and sediments seems to be important for engineering and especially environmental purposes. In this paper, laboratory tests were carried out to examine the effects of crude gasoline contamination on some of the geotechnical properties of a silty soil sampled from the Mashhad plain, located in the northeast of Iran. Tests consisted of basic properties, Atterberg limits, compaction, direct shear, and uniaxial compression tests, which were carried out on clean and contaminated soil samples at the same densities. The contaminated samples were prepared by mixing the soils with crude gasoline in the amounts of 3%, 6%, 9%, and 12% of dry weight and curing periods of 0, 7, 15, and 30 days. Results indicated a decrease in the friction angle and an increase in the cohesion of the soil by increasing gasoline content. Besides, a reduction in the maximum dry density and optimum moisture content was observed in the compaction test. The increase in gasoline percentage up to 6% also showed a direct effect on increasing the liquid limit and plastic limit of silty soil, which decreased thereafter. Moreover, any increase in gasoline percentage had a reverse effect on the modulus of elasticity of the soil. The increase in gasoline percentage up to 3% also had a direct impact on the uniaxial compressive strength of the soil, exceeding which it started to decline. Finally, the effects of contamination duration were examined by testing contaminated samples in periods of 7, 15, and 30 days under natural conditions. The results showed a reverse relationship with all geotechnical properties due to aging and a reduction in the gasoline content due to the evaporation of volatile compounds. Also, the numerical analysis of the laboratory results indicated an increase in settling and the percentage of shear strain beneath the foundation with increasing the contamination level, confirming the laboratory results.

Impacts of petroleum spills on geotechnical properties of soils: A review

“…Fine grained size soil do not show plasticity with non-polar fluids (Kaya and Fang, 2000;Ratnaweera and Meegoda, 2006;Rajabi and Sharifipour, 2018). Puri (2000) and Yazdi and Teshnizi (2021) reported that petroleum impaction caused meaningful alteration in soil compaction and permeability. Likewise, Yazdi and Teshnizi (2021) stated that petroleum caused significant changes in the soils' internal friction angle and constrained modulus; as these parameters decrease non-linearly as the petroleum quantity increases (from 0 to 12%).…”

“…Puri (2000) and Yazdi and Teshnizi (2021) reported that petroleum impaction caused meaningful alteration in soil compaction and permeability. Likewise, Yazdi and Teshnizi (2021) stated that petroleum caused significant changes in the soils' internal friction angle and constrained modulus; as these parameters decrease non-linearly as the petroleum quantity increases (from 0 to 12%). According to Nazir (2011) oil pollution generally reduced granular soils' permeability; but the effect of oil pollution on the permeability of clayey soils was not noticeable, which can be attributed to the poor dielectric constant value, initiated in the fines in the soil by the contaminant.…”

Petrology of lamprophyric in northern Jirandeh, Iran

“…According to Stoecklin's zoning (in which Alborz Mountains are divided into six formation zones from north to south), the study area is positioned in the southern central Alborz zone. In this zone, pre-Cenozoic shallow sedimentary deposits are covered by very thick volcanic rocks belonging to the Cenozoic era, especially Eocene (Stoecklin, 1974;Baratian et al 2020;Yazdi and Sharifi Teshnizi 2021;). According to the zoning of Engalence (1986), the study area is located in the central tertiary zone.…”

3D Inversion of Airborne Magnetic Data and Validation of it by Using Sourk Mine Drilling Data

“…These magnetic field changes would be related to local anomalies which can be interpreted concerning the local geological structures. Magnetic methods are used to map changes in susceptibility differences, exploration of ore deposits, the origin of mineral deposits, estimation of rock depth, identification of boundaries of rock units, detection of cracked zones, and finding faults and discontinuities (Oldenburg, & Pratt, 2007;Yazdi and Sharifi Teshnizi 2021). In this paper accuracy of airborne magnetic data geomodeling is validated by three-dimensional modeling of boreholes data of Sourk mine located in Yazd province.…”