STUDY ON DESIGN OF EARTHQUAKE-RESISTANT BRIDGES AGAINST TSUNAMI AND FLOOD

Abstract

 Although earthquake damage to bridges has been decreasing, countermeasures against multi-hazards, such as tsunamis after earthquakes and flood damage before and after earthquakes, are insufficient. In recent years, many bridges have been washed away or destroyed by floods in Japan. This study conducted numerical analyses of several types of flows to investigate the effect of using inspection platform as fairing for maintenance of bridges. By comparing the results with the bearing capacity specified in the seismic design specification for highway bridges, the conditions necessary to prevent girder washout in the event of flood damage are discussed. The results show that covering the lower half of the girder with a fairing, even if the fairing does not cover the entire girder, can reduce the hydrodynamic forces.