Assessment of prestressed concrete bridge girders with low shear reinforcement by means of a non-linear filament frame model

Abstract

The safety of existing bridges and the efficiency of strengthening measures can be accurately studied through non-linear numerical models, assisting decisions of dismantle, repair or change of use and avoiding unnecessary or inappropriate interventions. In this ambit, filament beam models due to their inherent simplicity and low computational demand are adequate for the engineering practice. Accordingly, in this paper, the structural assessment of a prestressed concrete bridge presenting low shear reinforcement, the Wassnerwald Viaduct in Switzerland, is presented. The bridge was dismantled due to, among other reasons, not complying with the safety standards related to shear. The girders of the bridge, which were submitted to full-scale in situ load tests, were numerically simulated by means of a non-linear filament beam model considering axial force (N)–shear (V)–bending (M) interaction. Hypothetical strengthening solutions for this bridge were also numerically studied: a shear strengthening through vertical prestressing and a bending strengthening through external longitudinal prestressing.

Keywords::

• prestressed concrete bridge
• structural assessment
• strengthening
• shear
• non-linear analysis
• fibre beam model

Acknowledgements

The present research has been carried out with the support of the projects: ‘Assessment of deteriorated, repaired and strengthened structures’ (BIA2009-11764), funded by the Spanish Ministry of Science and Innovation and ‘Performance-based-design of partially prestressed concrete structures. Proposal of new design methodology, experimental verification and design criteria’ (BIA2012-36848), financed by the Spanish Ministry of Economics and Competitiveness. Funding provided to the first author by the Portuguese Foundation for Science and Technology (FCT) and the European Social Found through the PhD grant no. SFRH/BD/43232/2008 is also gratefully acknowledged.

Notes

^1. Email: [email protected]

^2. Email: [email protected]