Study on the failure behavior of three di erent stabilized problematic soils

In this study laboratory testing of eectiveness of cement treatment has beenmade on geotechnical parameters of problematic soils encountered in southern coast line ofcaspian 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 compressivestrength, and elastic modulus of soils signicantly. triaxial test results indicated thatcement treatment not only improved shear strength remarkably, but also it changed thetype of failure greatly from ductile to brittle behavior. the large scale direct shear testresults showed signicant improvement in shear strength and shear modulus. besides, thebrittle behavior of cement treated samples was observed. eventually, it was found thatthe trend of failure envelope of cement treated samples was non-linear, and some failurecriteria such as modied grith theory, hoek-brown theory, and the johnston criterioncan describe the soil cement behavior satisfactorily.