Non-Linear Evaluation of Strengthening Techniques for the Champlain Bridge

摘要

The existing Champlain Bridge is a major structure in Montreal. It contains 50 concrete spans. The 10 ft (3.1 m) deep 1-girders span 172 ft (52.4 m) and are post-tensioned. Because the prestressing steel has suffered from corrosion, it was necessary to use advanced techniques to evaluate the performance of these I-girders. Detailed two-dimensional non-linear finite element modelling was used to determine the responses at service load and at ultimate. Three-dimensional finite element modelling was carried out to determine the loading for the two-dimensional modelling. The serviceability checks examined if cracking would occur and the strength requirements were evaluated using predicted demand-to-capacity ratios (D/C). These analysis tools also enabled the influence of a number of strengthening techniques to be assessed. The influence of different strengthening techniques on the predicted responses of the diaphragms was also studied. The combinations of strengthening measures were found to be effective in achieving the desired serviceability and strength requirements.