Probabilistic assessment of abutment-embankment stiffness and implications in the predicted performance of short bridges

This article investigates the bi-directional stiffness of abutment-embankment systems in highway overpasses, considering the contribution of the abutment foundation in the force-transfer mechanism and soil material uncertainty. Stiffness is probabilistically assessed through refined, three-dimensional nonlinear static analyses, after validation with large-scale experimental results. The force-displacement relationships as well as the corresponding variance are derived separately for different abutment configurations along the transverse and longitudinal direction. Application of the above expressions for the case of a well-studied highway overpass leads to distinctly different probability of failure at the system level compared to the prediction made based on conventional code-prescribed procedures.