The direct use of the experimental modal data of a bridge for the apposite calculation of the response of this bridge under dynamic even static load is described in this paper.

The experimental modal analysis is one of diagnostic methods. The experimentally - estimated modal parameters (frequencies, modes of natural vibration and corresponding damping values) realise the actual immediate state of the observed structure. These results of the experimental modal analysis can be used such as for an identification, an optimalization or a verification of a bridge design model. In addition the experimentally - estimated modal parameters of a bridge can be used for the creation of the modal model of this bridge. This modal model is suitable for execution of the apposite calculation of the response of the bridge under dynamic even static load. This paper presents that the described method is possible to use for the study of the vehicle/bridge interaction problem.