Abstract
A series of undrained shear triaxial tests were performed in this study on sand and sandy-gravel materials with different fines content and different relative density. According to the undrainened cyclic and monotonic loading triaxial tests, liquefaction strength and maximum deviatoric strength considerably reduce as the fine increases from about 10% to 20% having the same relative density. It clarified in this research that, when non-plastic fines are mixed in sand and sandy-gravel, undrained shear characteristics in cyclic loading and monotonic loading for virgin or post-liquefaction soils largely change. Hence, it is important to evaluate the influence of fines fraction on the undrained strength properties appropriately.
