Abstract:(Purpose)A three-dimensional finite element model of the tailings dam at its final elevation was established to validate the feasibility of the design scheme for increasing the height and expanding the capacity of a dry tailings dam on an overburden layer. (Method)The dynamic time-history analysis method was used to analyze the displacement, stress, acceleration, permanent deformation, and dam slope stability of the tailings dam under the heightening and expansion design scheme. Then, the influence of dynamic characteristic parameters and seismic peak acceleration on the dynamic response of the tailings dam was investigated. (Results)The results indicate that the tailings dam meets the seismic design requirements under the heightening and expansion scheme. And, there is a negative correlation between the dynamic shear modulus coefficient and the dynamic displacement response and a positive correlation with the acceleration response. The peak ground acceleration is positively correlated with both the dynamic displacement and acceleration response. (Significance)The research findings can provide a reference for decision-making by regulatory authorities.