Abstract: The effect of clay contents on the dynamic pore pressure in the saturated sands were studied with dynamic triaxial tests. Samples with clay contents of 0%, 10%, 20%, 30%, 40% and 50% were prepared for the tests. The failure criterion of the triaxial tested samples was set to have an axial strain of 5%. After the sample was failed, the peak pore pressure values that correspondent to each cycle were recorded. The results indicate that, when the clay content is less than 20%, the ratio of peak pore pressure increase in the saturated sand increases with the clay contents. Therefore, the clay content helps the peak pore pressure increase. When the clay content is more than 20%, the peak pore pressure increase ratio is reduced by the increase of clay content. When the clay content is greater than 40%, the increase of pore water pressure is completely blocked by the clay content, an approximately constant peak pore pressure was observed after the failure. The regression analyses were also performed on the curve fitting of the current parameters.

Key words: Clay Particle Content, Silty Fine Sand from Li-Jiang River, Isotropic Consolidation, Pore Water Pressure