Seismic design of deck isolation systems for continuous girder bridges

The paper deals with the seismic design of deck isolation systems for continuous girder bridges. The discussion is focused on the seismic retrofitting of existing reinforced concrete (RC) girder bridges by means of friction pendulum (FP) isolators. Notwithstanding, the design framework is general purpose and can be employed for various seismic isolation systems. The design method is firstly described and subsequently the results of its application to a case study are illustrated. The sample structure is a typical RC highway bridge designed and constructed during the 1970s without seismic detailing. The case study is part of an ongoing comprehensive numerical and experimental research program funded by the European Commission. The design assumptions are illustrated and checked through non linear dynamic analyses of the case study bridge models with different levels of refinement; two sets of acceleration records are utilized in the performed analyses. The outcomes of the present work demonstrates the efficiency of the proposed displacement-based design method