The goals of this project are to develop a rod shear device to study shaft friction, to develop experimental techniques to measure changes in tangential stress in soil near a pile, and to measure how the state of stress near the surface of a pile changes due to axial loading on the pile. A granular soil will be confined in a rod shear device that can apply anisotropic confinement to the soil specimen. The tangential stresses in the soil will be measured by the velocity of compression waves in the tangential direction near the surface of the rod using miniature geophones and piezoelectric crystals embedded in the soil specimen.
