Influence of spatial variability of ground motion on response of large concrete arch bridges

Effects of the seismic wave passage and the loss of coherence of ground motion on response of large reinforced concrete arch bridges are analyzed. Numerical models are constructed on the basis of “as built” bridges on the Adriatic Coast, calibrated with the results of extensive static and dynamic test loadings. Seismic analyses are performed by piecewise exact step by step method.

Asynchronous seismic records are generated by the conditional simulation method where a set of ground motions at different bridge supports is produced from a natural record at one location. Real ground motion time-history recorded on the Adriatic Coast is used in the analysis. In order to compare results of the analyses, bridges are also subjected to identical ground motion at supports. Effects of wave passage and incoherence are evaluated separately and the case of both effects acting simultaneously is additionally considered.