ABSTRACT
Evaluating the structural health of a bridge is a complex activity. Small and medium bridges constructed in urban areas often undergo to many changes during their service life. Partial reconstruction, increased traffic loads, a new structural schema are some of the changes occurred in the Tannery Bridge (Switzerland) over time. These changes were only partially documented. Therefore it was necessary to understand the structure and its behavior prior to assessing its load carrying capacity and the pathologies, before proposing a refurbishment strategy. Furthermore, some important elements were documented but not constructed as stated in the plans. No transition slabs were ever planned and the ramps constructed to access the bridge were rapidly deforming due to the low quality of the foundation soil. Although the concrete deck is not in critical conditions, some degradation is visible and rapidly progressing. The curbs and barrier types obliged the engineers to plan the demolition and to change these important details. This article presents the analyses and the design process for the rehabilitation of the Tannery Bridge, an urban bridge that, in about 5 decades, was completely changed and resisted to unexpected loads such a number of heavy military tanks. Furthermore it will be shown how, sometimes, minor problems may become the real challenge, at least from the financial point of view
