Seismic response of repaired bridges by pseudodynamic tests

Eight bridge circular pier specimens (1:6 model of the most stressed piers) severely damaged after previous pseudodynamic and cyclic tests until failure, were repaired and/or upgraded by means of epoxy adhesive, stainless steel rebars, self compacting concrete and C-FRP wrapping and tested by pseudodynamic, under the seismic action used for first tests on undamaged specimen. The undamaged pier specimens were representative of tall and squat circular r.c. piers designed according to Eurocode 8 or Italian Code before 1986. In the pseudodynamic test, the repaired and/or retrofitted piers specimens (one column per bridge) are physically tested in the lab, while the rest of the bridge is numerically simulated. Damage states after the previous tests are assessed and description of the repairing and retrofitting of the piers as well as the description of the In-House pseudodynamic apparatus and dedicated software implemented using LabVIEW and MATLAB are given. Finally a comparison between the seismic behavior of the original and the retrofitted bridge piers are shown in terms of seismic response. Tests results are compared to nonlinear analyses using the computer program OpenSees. Results are discussed. © 2010 Taylor & Francis Group, London.