Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 53 11 2022 01 21 Evaluation of the Effect of Anionic Surfactant of Sodium Dodecyl Sulfate on Undrained Shear Strength Parameters of Crude Oil Contaminated Loose Sand Evaluation of the Effect of Anionic Surfactant of Sodium Dodecyl Sulfate on Undrained Shear Strength Parameters of Crude Oil Contaminated Loose Sand 4931 4950 4212 10.22060/ceej.2020.18637.6914 FA Naeem Gholampoor Department of geotechnical engineering, faculty of engineering, Imam khomeini international university, Qazvin, Iran Seyed Abolhasan Naeini Department of geotechnical engineering, engineering faculty, Imam khomeini international university, Qazvin, Iran 0000-0001-7711-3087 Reza Ziaie Moayed Department of geotechnical engineering, Engineering faculty, Imam khomeini international university, Qazvin, Iran Journal Article 2020 06 25 <span style="letter-spacing: .05pt;">Contamination of soil with petroleum products due to leakage from oil tanks and pipelines causes damages to the environment and human life and in addition to severe environmental damages, depended on soil type, causes changes in its strength characteristics. One of the most important methods for crude oil remediation is the soil washing technique which can affect on strength of contaminated and also natural soil in addition to their effects on the degradation process. This study aims to investigate the effect of using soil washing technique using anionic surfactant of sodium dodecyl sulfate (SDS) at different concentrations on the degradation process of crude oil contamination and also, undrained shear strength parameters of loose sand contaminated by various concentrations of light crude oil. The results indicate that, under all confining pressures, by an increase of crude oil content up to around 5%, the shear strength of sandy soil decreases and then increases for crude oil content more than 5%. Also, reduction in internal friction angle and increase of cohesion by an increase of crude oil concentration are the results of this study. Soil washing by using different concentrations of SDS solution increases the shear strength of crude oil contaminated sandy soil, but the rate of this increase is lower at crude oil contents greater than 5% and high confining pressures. As a general remark, it can be said that the shear strength of both crude oil-contaminated sand and contaminated sand washed by a surfactant is less than the same for clean sand</span>. <span style="letter-spacing: .05pt;">Contamination of soil with petroleum products due to leakage from oil tanks and pipelines causes damages to the environment and human life and in addition to severe environmental damages, depended on soil type, causes changes in its strength characteristics. One of the most important methods for crude oil remediation is the soil washing technique which can affect on strength of contaminated and also natural soil in addition to their effects on the degradation process. This study aims to investigate the effect of using soil washing technique using anionic surfactant of sodium dodecyl sulfate (SDS) at different concentrations on the degradation process of crude oil contamination and also, undrained shear strength parameters of loose sand contaminated by various concentrations of light crude oil. The results indicate that, under all confining pressures, by an increase of crude oil content up to around 5%, the shear strength of sandy soil decreases and then increases for crude oil content more than 5%. Also, reduction in internal friction angle and increase of cohesion by an increase of crude oil concentration are the results of this study. Soil washing by using different concentrations of SDS solution increases the shear strength of crude oil contaminated sandy soil, but the rate of this increase is lower at crude oil contents greater than 5% and high confining pressures. As a general remark, it can be said that the shear strength of both crude oil-contaminated sand and contaminated sand washed by a surfactant is less than the same for clean sand</span>. https://ceej.aut.ac.ir/article_4212_44b422a6d1df1d47db5d50a8d0aaca5d.pdf