The use of dispersive soils, which are common in many parts of the world, in engineering applications such as water structures, earthen dams and road embankments is possible with their improvement. Recently, the effects of different chemicals on the stabilization of dispersive soils have been investigated. The use of waste materials in stabilization is preferred both because of the more sustainable environment and the economic advantages it provides. The use of silica fume (SF) as a waste material in different engineering applications provides an important advantage in environmentally and economically sustainable ways. Many studies have been carried out regarding silica fume, especially in the construction industry. Although SF is used in many industries, there is no study about its potential impact on the stabilization and dynamic properties of dispersive soils. In this study, first, Atterberg limits and standard Proctor compaction tests were performed on the mixtures prepared by adding different SF percentages (0, 5, 10, 15, 20, 25 and 30%). Afterward, pinhole tests and resonant column tests were performed to determine dispersibility and dynamic properties on the samples prepared by compaction characteristics for each SF percentage reached. In general, it was determined that SF contributed to a change in soil class, and improvement in dispersibility and dynamic properties of the soil sample, depending on SF content; positive effects of SF were observed in terms of shallow soil improvement.

Dispersive soils are one of the problematic soils such as swelling and collapsible soils and they are common in many countries of the world. Due to dispersive soils, significant problems arise in road embankments and earth dams. Therefore, the use of such soils is possible with treatment. Silica fume (SF) as a waste material has been used in concrete production instead of partially cement, in the stabilization of expansive soils and in many civil engineering applications for different purposes. Within the scope of this study, to determine the dispersibility behavior of the soil sample, crumb test was performed. SF additive was used to improve the soil sample, which was determined to have high dispersibility. The compaction properties of the soil specimens mixed with SF in different proportions (0, 5, 10, 15, 20, 25 and 30%) were determined by the standard Proctor test. Crumb tests were performed to assess the dispersibility potential of the prepared specimens, and also unconsolidated and undrained (UU) triaxial tests were carried out to evaluate the strength parameters. UU experiments were performed under 20 kPa, 40 kPa and 60 kPa effective cell pressures on specimens cured for 1, 7 and 28 days because stabilization occurred at shallow depths in field applications. As a result, it was determined that the dispersibility feature of the soil sample was treated and the strength properties were improved depending on the SF content.