Seismic analysis and retrofitting of an existing R.C. highway bridge: investigation through pseudo-dynamic tests

The “Retro” TA project funded by the European commission within the Series-project aims at studying numerically and experimentally the seismic behaviour of an old existing reinforced concrete bridge with portal frame piers and the effectiveness of different isolation systems. In particular, an experimental test campaign will be performed at ELSA Laboratory of JRC (Ispra, Italy). Two piers (scale 1:2.5) will be built and tested using the PsD technique with sub-structuring; the modelling of the entire viaduct is considered along with the non-linear behaviour of each pier, due to bending, shear on the transverse beams and strain penetration effect at the column bases. The comprehensive numerical investigations have shown the high vulnerability of the sample bridge. Consequently two isolation systems (yielding-based and friction-based bearings) have been currently designed and characterized. Because the test will start after the summer 2012, in this paper the relevant issues will be here addressed and discussed.