Rotation of Principal Stress Axes in Direct Shear Tests of sahds and its Applications.

摘要

In direct shear tests, principal stress axes gradually rotate during the increase of shear stress τ under the constant normal stress σN. Besides, the strain increment in the horizontal direction is confined the condition of zero, wheares, it is not zero in the vertical direction. In this paper, by modifying the relationship between the stress ratio on the horizontal plane τ/σN and the inclination angle ψ of the major principal stress axis to the vertical direction, τ/σN=K, tan ψ, the principal stresses σ1, σ3 in the direct shear tests are determined and the behaviors of sands, which satisfy the plane strain condition, are quantitatively explained.