Comparison between the Discrete Element Method and the Finite Element Method to the cyclic response of a semi-integral bridge abutment backfill
Discrete element method (DEM); Semi-integral bridge; Earth pressure; Cyclic behavior.
Integral and semi-integral bridges are alternatives for conventional bridges, which routinely present problems associated with expansion joints and bearings. However, the cyclic lateral displacements of the superstructure, induced by temperature variations, lead to a complex interaction between the backfill and the abutment of an integral or semi-integral bridge, which requires in-depth assessment of the behavior of these bridges. In this research, ISSS’s Rocky software was used to build a computational model based on the discrete element method (DEM) for investigating the response of a granular backfill to the cyclic displacements a semi-integral bridge abutment located in Texas, USA. In order to limit the number of particles and computational time, the model was limited to a portion of the backfill at the top of the abutment only. The cyclic sequence of imposed lateral displacements was chosen to simulate the completion of the bridge in the autumn. The prescribed lateral displacement magnitude of ± 2.5 mm was selected to represent the annual cyclic response of the bridge. Results indicated an increase in the lateral earth pressure coefficient on the abutment face and an increase in the settlements on the backfill surface after each cycle of movement of the abutment. A good agreement was found between the results obtained in the present work and results obtained from simulations performed for the same bridge using the finite element method (MEF).