3. Recalculation of structures

In what follows, only the recalculation of road bridges is dealt with. In view of the obvious safety issues, both structural and operational, the recalculation of rail bridges can only be the responsibility of a specialized authority.

When a bridge shows signs of damage, it means that the reversibility stage of certain service limit states has been more or less largely exceeded. In the case of steel bridges, local fatigue damage means that the structure is inexorably moving towards an ultimate limit state that could put it out of service. As mentioned above, the aim of recalculation is to develop a model of the structure in question, to provide a reference state characterizing its probable behavior, and to define the principles of repair or reinforcement. This reference condition will facilitate any subsequent investigations. The recalculation should make it possible...