Evaluation of the effect of nano-illite on compressibility and Atterberg limits of loess soil (silty clay), Gonbad Kavous Kavous city (Golestan province)

Loose soils (CL-ML silty clays) are one of the most important problematic soils that have caused various geological hazards in the world, especially in Iran. Therefore, in order to reduce the geological hazards of such soils, it is necessary to make changes in their geotechnical properties. The aim of the present study is to investigate the effect of nano-illite on the geotechnical properties of loess soil including Atterberg limits and compressibility. For this purpose, a loose soil sample was prepared from Gonbad Kavous city of Golestan province and geotechnical tests including Atterberg limits and compaction were performed on it. Tests were performed on soil samples with percentages of 0.5, 1, 1.5, 2, 3, 4, 5 and 8 nano-ilite. The results show that in the Atterberg limits test, the plastic limit is from 19% (without nano-illite) to 36% (in 8% nano-illite) and the liquid limit is from 26% (without nano-illite) to 40% (with 8% nano-illite) have increased. Also, in the compaction test, the maximum dry unit weight increased from 1.97 g /cm3 (without nano-illite) to 1.99 g /cm3 (in 2% nano-illite) and then decrease to 1.96 g /cm3 (in 4% nano-illite), while the optimum moisture has continuously increased from 12 to 12.9% in 0 to 4% nano-illite, respectively.