Seismic reliability assessment of typical road bridges in areas of moderate seismicity

Prior to modern seismic codes, several road bridges were not designed for earthquakes in many moderate seismic regions. The seismic performance of these bridges is questionable. A portfolio of 30 non- seismically designed bridges is compiled for seismic reliability assessment. Fragility analysis is conducted, the reliability of each structure is determined considering typical moderate seismic areas. The study shows that slab and multi-girder bridges with elastomeric bearings perform worse; girder bridges with conventional bearings and multi-girder bridges with monolithic joints have better behavior. It is also shown that seismic design per Eurocode 8 leads to a reliability index of ~2.