This study investigates the effects diesel, on soil mixtures of kaolinite and bentonite and explores the potential improvement of these soils using biochar produced from almond shells. Additionally, the impact of wet-dry cycles on the strength and durability of stabilized soils is eva‎luated. The primary goal of this research is to provide environmentally sustainable and effective solutions for the remediation of contaminated soils. in this research, Soil samples with varying percentages of bentonite, diesel contamination, and biochar were prepared and eva‎luated under laboratory conditions. Results indicated that biochar can significantly enhance the mechanical properties of contaminated soils. The tests showed that the addition of biochar increased the compressive strength and reduced the swelling of diesel-contaminated soils. The results demonstrate that biochar, by reducing permeability and improving the bearing capacity of the soil, can serve as an effective stabilizer for remediating contaminated soils. Furthermore, the effects of wet-dry cycles on stabilized samples were investigated. These cycles led to a reduction in soil strength and durability, but the application of biochar significantly mitigated the negative impacts of these cycles. Specifically, the parameters of biochar content and contamination level were identified as the most influential variables on soil strength. Statistical analysis using the Design Expert software showed that the proposed model has a good ability to estimate and predict the mechanical behavior of the samples. Based on the F-value and P-value, biochar content and contamination had the greatest impact on the cohesion and internal friction angle of the samples. These findings highlight the high potential of biochar in improving the physical and mechanical properties of contaminated soils and emphasize that biochar stabilization could be a sustainable and effective solution for reducing the adverse effects of oil contamination.

محمدرضا خان محمدي

محمدعلي روشن ضمير , امين ازهري