Through the dynamic triaxial tests and the resonant column apparatus tests of the tailings material taken from a copper mine

the dynamic deformation properties are studied. From the experiment results

a practical strain pore-water pressure model is given and a formula to forecast the dynamic pore-water pressure is presented. Compared with Seed’s forecast formula

the formula can forecast the dynamic pore-water pressure of saturated tailings material more precisely. Based on the effect of different relative density on liquefaction property of tailings material

a conclusion is drawn that the liquefaction strength will obviously increase with the increase of relative density before the relative density is less than 70%. From the dynamic triaxial tests with different confining pressures

it is found that the dynamic shear stress ratio is less while the confining pressure is more in the condition of the same vibration times. Through the resonant column apparatus tests

it can be found that the damping ratio will increase with the dynamic shear strain increases

while dynamic shear modulus will decrease at the same time. And another conclusion that the relationship between dynamic shear modulus and damping ratio with dynamic shear strain is not sensitive to the confining pressure can be drawn.