Influence of Lateral Stress Ratio on N-Value and Cyclic Strength of Sands Containing Fines

Abstract

The compaction method, such as the sand compaction pile (SCP) method, is a method to increase the strength of the ground by installing the material into the ground to be improved. However, in the standard penetration test (SPT) and cone penetration test (CPT) of the in-situ sounding test to confirm the improvement effect, the effect of density increase has been sufficiently evaluated, but the effect of lateral stress has not been evaluated. The authors investigated the effect of the lateral stress ratio, Kc-value and presented a relationship between the normalized N-value, N₁ of the standard penetration test and cyclic strength based on the results of soil chamber tests and hollow torsional shear tests under anisotropic condition of clean sand. This relationship was analyzed using the same method that led to this relationship against sands containing fines. As a result, a design chart of the ground (recommended chart), which is the relationship between the two considering the fine content, was presented.