Department of Civil Engineering, Amirkabir University of Technology, Tehran, Iran
Department of Civil Engineering, Central Teharn Branch, Islamic Azad University, Tehran, Iran
In this study laboratory testing of eectiveness of cement treatment has been made on geotechnical parameters of problematic soils encountered in southern coast line of Caspian Sea, Iran. Gorgan loess, Rasht clay, and Anzali sand were selected in this research. Addition of cement was found to improve workability and increased unconned compressive strength, and elastic modulus of soils signicantly. Triaxial test results indicated that cement treatment not only improved shear strength remarkably, but also it changed the type of failure greatly from ductile to brittle behavior. The large scale direct shear test results showed signicant improvement in shear strength and shear modulus. Besides, the brittle behavior of cement treated samples was observed. Eventually, it was found that the trend of failure envelope of cement treated samples was non-linear, and some failure criteria such as modied Grith theory, Hoek-Brown theory, and the Johnston criterion can describe the soil cement behavior satisfactorily.