Selection of time-histories for bridge design in Eurocode 8

Eurocode 8 (EC8) allows the use of real earthquake records as an input for time-history analysis of structures. In its Part 2, the code discusses the preparation of seismic input for bridge structures; although referring to the same design spectral shapes of Part 1, the prescriptions for bridges are somewhat differently specified in respect to those for buildings. The main requirement the chosen record set should satisfy, is the compatibility of the horizontal average SRSS spectrum with the design spectrum in a broad range of periods. The set has to be made of at least three recordings, but seven is the minimum set size to consider the mean structural response as the design value. The code seems to indicate real records as the principal source of ground motions the practitioner should rely on, however the selection of real records is not straightforward and requires searching of large databases to find sets compliant with the code spectrum. In another study, the authors discussed the record selection prescriptions in EC8 Part 1, herein these issues are reviewed in respect to the specific requirements given in EC8 Part 2, and the European Strong-motion Database is searched to identify real record sets matching the design spectral shapes for several site conditions.