Abstract: Based on secondary development of abaqus with the application of Fortran language，the Duncan E-υ model and the equivalent viscoelastic Umat subroutine are prepared. The 3D dynamic response and liquefaction analysis of tailings dam are made by the effective stress method. The acceleration，dynamic shear stress，the trend of the dynamic pore pressure and liquefaction zone of the Beipiao tailings dam in Liaoning province under normal conditions are calculated. The result of the dynamic computation shows that the magnification factor of along dam axis direction acceleration is 1.82 and the maximum values is on the slope surface of the embankment of 3/4 height of the dam; the maximum dynamic shear stress，which shows layered distribution，decreases gradually from the inside slope to the outside slope; dynamic pore pressure increases as irregular curve patterns，in the 2～6 s meizoseismal area undulated greatly，then leveled off. The liquefaction zone is mainly concentrated in the deposited beach shallow area and following the top of the dam infiltration，and not through the dam.

Key words: Tailings dam, ABAQUS, Dynamic pore pressure, Liquefaction analysis