A proposal for the improvement of the earthquake resistance of multi-span precast I-beam bridges

Abstract

This study proposes an innovative restraining system for the improvement of the earthquake resistance of precast concrete I-beam bridges mainly in the longitudinal direction. The proposed method is based on the connection of the continuous deck slab of the bridge through the sidewalks with both abutments and the elimination of the end expansion joints. In this way, the bridge obtains four restraints (one per wing-wall), which behave as tension ties during the deck contraction and have the ability to reduce the seismic movements of the deck. The resultant in-service requirements due to creep, shrinkage and thermal effects are properly accommodated. Each sidewalk is divided to zones that are anchored to the deck and zones that have the ability to slip on the deck. The efficiency of the proposed method is investigated by utilizing a precast I-beam bridge of Egnatia Odos Motorway in Greece. This bridge has been converted to a ductile bridge system by using active seismic stoppers at the head of the piers.