Development of a methodology for the optimized planning of retrofitting and/or replacement of important bridges

  • Many of the federal highways built before 1985 have a load-bearing capacity that is not sufficient to withstand the present or predicted freight traffic loads.


    The project focused on the planning of necessary retrofitting and/or replacement measures for the bridges concerned. The project carries forward the work of a preceding project where a prototypical procedure was developed which, by means of an optimised retrofitting program, minimises the overall economic impact due to unavailability or limited usability of the bridges in a sub-network.

    The methodology was applied to selected Rhine crossings in North Rhine-Westphalia between Bonn and Duisburg.

    In the ongoing project the method is being further developed with the aim of applicability for larger sub-networks. The aim of the project is then to develop a software prototype for the calculation of optimized retrofitting programs.


    Method for preselecting structures

    The procedure for the pre-selection of structures under structural and macroeconomic aspects intends to identify particularly critical structures at an early stage in order to include them in a procedure for planning measures on sub-network level.

    Methodology for the analysis of retrofitting options

    The aim of the methodology is to appraise the structural effects achievable with the retrofitting options and to assess the overall economic and traffic effects.

    Methodology for the establishment of retrofitting programs for sub-networks

    The aim of the retrofitting program is to generate the highest possible overall economic benefit for the selected sub-network or to keep the user costs caused by the maintenance or measures as low as possible.