Investigations on dynamic proberties of a railway bridge at different stages of construction

Dynamic properties of a two-track railway bridge, constructed as a concrete frame structure, are measured using forced excitation at different stages of construction. Goal of the experimental investigations is a quantitative assessment of the individual changes in stiffness and damping. The dynamic properties measured at different stages of construction are compared and discussed with results from a numerical calculation prior to the measurements. The results of the investigations show, that addition of elements during the construction in a short time period has a minor influence on the first eigenfrequency. The damping of the fist eigenfrequency according to Lehr rises with a higher degree of completion.