The investigation of sheer strenght's low plasticity sand-clay mixtures

Key Words: clay, shear strength, shear strength angle, cohesion, shearbox, triaxial, pressure Shear strength parameters of soils are main interest in geotechnical investigations. Main determinative parameters of shear strength are shear strength angle (?) and cohesion (c). These parameters can be defined by insity and laboratuary experiments on undistrubutes soil samples. There are many reasons have effects on shear strength of soils. Soils can be find in different types such as clay, silt, sand and gravel in the nature. The efeects of sand grains on shear strengrh in small grained soil, is investigated in this thesis. This research has been carried out to observe the changing of shear strength in the silt and clay samples of soils which contains in different percentage and grain of sand. In the study, above the diameter of 0,074mm and 0,2mm,and below the 0,2mm and 0,6mm grain sites of sanda remixed by 10%, 25%, 50%, 75% in the size of below the 0,074mm clay samples and the chainging of shear parameters has been observed by shear box and triaxial pressure tests, additionally the findings of the shear box and triaxial pressure tests results have been compared. According to the test results; sand was saving, it is own features when the clay samples has 50% of sand. Although cohesion stays in the some level, shear strength angle gives different values in shearbox and triaxial pressure tests.