Method     After verifying the centrifuge model,a three-dimensional numerical model of the widened embankment and the original embankment was established using Abaqus. Based on the comparative analysis, the influence of gravity, deformation modulus, strength parameters of widened embankment on the mechanical characteristics, deformation behavior and failure mode were carried out.

      Result     The numerical simulation results show that the piles under the embankment had different contributions to anti-sliding. The piles close to the slope are mainly subjected to bending and shearing, and the piles far away from the slope are mainly affected by the axial force. The weight of the widened embankment affects the mechanical characteristics of the pile in the original embankment: the main performance is that the bending moment and shearing for piles in the original embankment reduced, and the axial force increased; the displacement of piles in the original embankment increased, in which the vertical displacement increment near the original slope foot is the largest and the largest lateral one is located in the middle of the original embankment. The soil weight of the widened embankment significantly affects the vertical displacement of the original embankment, but its deformation modulus and strength parameters almost have no obvious effect. After the embankment is widened, the mechanical characteristics of the pile in the original embankment change under the load. The potential failure mode is changed from bending-shear zone, bending zone and compression zone to bending zone and compression zone.

      Conclusion     The model can verify the centrifuge test results, and the results can provide guidance for the stability analysis of embankment widening.