The behavior of loose sand-structure interface under the high frequency cycle shearing is analyzed by using Particle Discrete Element Method (DEM).The changes of sand box porosities of DEM model and sand volume strains are examined in detail.The results show that sand volumetric shrinkage due to shearing is not obvious in spite of the larger loose sand particle friction coefficients and particle stiffness.The particle stiffness ratio has a little effect on the mechanical properties of sands.In addition

the decrease in volume of sand under shearing is more obvious with the increase of the confining pressures.Moreover

the decrease in volume of loose sand under shearing is greater with the increase of the high frequency cycle shear amplitude and the shear frequency.