Abstract: The dynamic modulus damping ratio of the tailings silt damming material of a tailings dam was tested using the GDS dynamic triaxial apparatus. The dynamic stress-strain characteristics of tailings silt were examined, and the effect of confining pressure and consolidation ratio on the maximum dynamic shear modulus as well as dynamic shear modulus ratio and damping ratio were analyzed. Moreover, the modified formulae for the maximum dynamic shear model and modulus attenuation which could normalize the influence of consolidation ratio was proposed based on Zhujiang Shen’s dynamic constitutive model. Test results demonstrated that with the rising of confining pressure and consolidation ratio, the dynamic elastic modulus of tailings silt increased while damping ratio decreased. With the augment of dynamic strain, the dynamic shear modulus ratio reduced while damping ratio increased. The modified formulae could normalize the effects of consolidation ratio and confining pressure on the maximum dynamic shear modulus and modulus attenuation, and thus accurately reflecting the dynamic deformation characteristics of tailings silt.

Key words: tailings silt, dynamic triaxial test, dynamic modulus, damping ratio, dynamic shear modulus ratio, dynamic constitutive model, consolidation ratio