CYCLIC UNDRAINED TRIAXIAL STRENGTH OF SAMPLED SAND AFFECTED BY CONFINING PRESSURE

Abstract

The effects of confining pressure on the cyclic undrained triaxial strengths of intact sandy specimens obtained by sand sampling methods were investigated. It was found that the ratio of cyclic deviator stress amplitude to initial confining pressure required to cause a certain value of cyclic axial strain amplitude at a certain number of loading cycle in an intact triaxial specimen increased significantly with the decrease in confining stress when the laboratory confining pressure was less than the in situ confining pressure. However, it was also found that cyclic undrained triaxial strength expressed by stress ratio decreased only slightly with the increase in confining pressure when the laboratory confining pressure was larger than the in situ confining stress.