Aiming at the complicated characteristics of embankment fillings such as over-consolidation

dilatancy

and time-dependent deformation under hierarchical compaction

a high-filled embankment with multilevel retaining walls was took as an example to study the mechanical properties of backfill soil by means of site survey

indoor test and deformation monitoring.The Mohrcoulomb model

Modified Cam-clay model and an elastic-viscoplastic constitutive model based on sub-loading yield surface were used in turn to reproduce the over-consolidation

diatancy and time-dependent behaviors of embankment backfill.The parameters of the above three constitutive models were comprehensively determined by data inversion of unit test and field settlement monitoring.Settlement during and after embankment construction obtained from the three models was compared analyzed

and the stability of the embankment was investigated through the finite element strength reduction method.The results show that since the pre-consolidation pressure was taken into account

the settlement calculated through the elastic-viscoplastic constitutive model and the modified Cam-clay model is smaller than that through the Mohr-Coulomb model during the initial stages of construction（21 days）.The predicted settlements obtained by the three models are close to each other when the consolidation stress exceeds the pre-consolidation pressure during the process of construction（100 days）.However

only the elastic-viscoplastic constitutive model based on sub-loading yield surface can predict the long-term settlement of the embankment

and the simulated post-construction settlement at the embankment surface is 17 cm at the end of the 10 th year after construction

which satisfies the post-construction settlement requirement.A′S′shape is observed in the horizontal displacement curve of the embankment.Both the factor of safety and the critical sliding surface obtained through strength reduction method can well meet the requirements of slope stability.The warning displacement for ensuring the stability of the embankment slope is 4.6 cm.