The 3D multi-mechanism model based on the Hardin-Drnevich model and generalized Masing rule can take into account the nonlinearity and stress-induced anisotropy in stress-strain relationship for granular materials.Based on the platform of the finite element software ABAQUS

the subroutine of the 3D multi-mechanism model is implemented and then the seismic response analysis of a rockfill dam is possible by using this model.The seismic response analyses of the asphalt-concrete-faced rockfill dam are carried out by using the 3D multi-mechanism model and the equivalent viscoelastic model under a strong earthquake.The dynamic response characteristics of the dam and the effect of constitutive models on its response are investigated.The result shows that there exist some differences in the dynamic responses of the dam computed by using the two constitutive models.The 3D multi-mechanism model can accurately simulate the complex stress-strain relationships of rockfill materials under earthquake loading and the result obtained by it can reasonably reveal the nonlinear seismic response characteristics of the dam.