OA 498 and 499 bridges in Luxembourg
The two bridges across the Esch-sur-Sûre lake at Insenborn and Lultzhausen were built in the 1960s of pre-stressed concrete girders.
Following the detection of damage to these structures, the Luxembourg Public Works Department decided to replace them.
These bridges provide tourist access to the various beaches of the lake, and the main planning constraint was that the works should not disrupt traffic during the summer period.
Bureau Greisch was approached by the contractors to develop a phasing plan for the works in order to reduce construction cost and time.
The chosen solution was to erect the new bridge in successive launching phases, having first built the deck on an assembly platform, and using this new structure as a route for removing the existing bridge sections.
In contrast to the basic solution consisting of the complete demolition of the bridge as a first phase, followed by the construction of a new bridge, Greisch’s proposal meant that demolition and rebuilding could take place simultaneously, thus ensuring the works could be completed with the timeframe.
Development of the assembly method, assembly studies and checks on the bridges in service