Efficient 1D model for blind assessment of existing bridges: simulation of a full- scale loading test and comparison with higher order continuum models

Assessing the structural performance of existing concrete bridges is nowadays a major task. Nonlinear finite element (FE) analysis can quantify their capacity, evaluate strengthening interventions and prevent premature dismantle. However, this technique, mainly performed with 2D/3D FE, is seldom used at true scale due to the great complexity and computational costs involved. In this paper, the loading test of a strengthened concrete bridge in Sweden (ornskoldsvik) is simulated using a 1D model. The bridge failed in combination of shear-bending-torsion triggered by fibre-reinforced polymer bond failure. Consecutive levels of refinement of the 1D model are presented and available results from higher order models are compared. The study of the structural response involved comparing displacements, strains, cracking patterns and failure mechanisms. The demonstrated robustness and efficiency of the proposed model makes it adequate for blind assessments of existing bridges.