The Fully Automatic Static-dynamic Tri-axial Shear Apparatus is used to perform three-axis dynamic shear tests for Fujian Standard sand under isotropic and anisotropic consolidation

and the dynamic characters of the saturated sand under different vibration modes are compared

such as axial vibration

radial vibration

axial-radial coupled vibration with phase angles 0°and 180°.It is shown that

on condition that dynamic deviator stress levels on the maximal shear stress surface are same

the influence of any of the four shearing modes on the dynamic stress-strain relationship and the dynamic strength is not significant no matter it is isotropic or anisotropic consolidation.Because the deviator stress level of the maximal shear stress is the combined action of axial and radial vibrations

the aseismic design without considering the cyclic axial stress is biased unsafe.