Abstract
Three kind of marine clays with various plasticity and silica sand were mixed at different proportions, and specimens were prepared either by water sedimentation or by pre-consolidation. Then, a series of consolidation and undrained shear tests were performed on the specimens. Thus, soil samples with broad grain size distribution, i.e. ranging from sand to clay, were formed and, based on the test results, a unified method to evaluate the undrained shear strength of sand-clay mixtures was proposed. When the fines content is low, a soil mixture is formed such that the sand particles form the soil matrix while the finer particles occupy the void spaces in between. The strength of the soil mixture is dependent on the void ratio formed by the sand matrix. On the other hand, when the fines content is increased up to a certain point, the fines dominate the matrix structure of the soil, with the coarse sand particles scattered around, resulting in the strength of the mixture being controlled by the characteristics of the finer particles.
