JAPANESE PRACTICE IN SEISMIC DESIGN OF PRESTRESSED BRIDGES

DAMAGE TO AND RESISTANCE OF PRESTRESSED BRIDGES ARE RELATED TO DESIGN PRACTICE, WHICH IN TURN IS COMPARED WITH THE JAPANESE CODE. VARIOUS TYPES OF PRACTICAL EARTHQUAKE- RESISTANT MEASURES ARE DESCRIBED. DYNAMIC ANALYSES ON CONTINUOUS BRIDGES EQUIPPED WITH DAMPERS DEMONSTRATED THEIR EFFECTIVENESS IN AVOIDING EXCESSIVE AMPLIFICATION OF DYNAMIC RESPONSE IN THE LONGITUDINAL DIRECTION. VISCOUS DAMPERS ARE EFFECTIVE ONLY IN THE LONGITUDINAL; DYNAMIC RESPONSE IN THE TRANSVERSE DIRECTION COULD BE 2--3 TIMES GREATER THAN THE JAPANESE CODE RESPONSE.