VERIFICATION OF EARTHQUAKE RESISTANCE OF AKASHI-KAIKYO BRIDGE

The Hyogoken-Nambu Earthquake, which struck Japan on January 17, 1995, had an epicenter very close to the Akashi-Kaikyo Bridge. The earthquake caused seabed ground movements in the vicinity of the bridge, which was under construction at that time. As a result of relative displacement of the bridge foundations, the central span of the bridge was extended by about 80 cm. A number of investigations into the effects of the earthquake on the bridge were carried out immediately after the event. These checks led to some remedial steps, such as a change in stiffening girder length, but almost no damage to the main structure was found. The bridge was completed successfully with safety and its function ensured. Since this earthquake occurred directly beneath the bridge, and such an occurrence had not been considered in the original earthquake-resistant design of the bridge, the Honshu-Shikoku Bridge Authority decided to check the bridge in its completed state for resistance to an earthquake of the same scale as the Hyogoken-Nambu Earthquake. This paper describes the study used to verify the earthquake resistance of the bridge and summarizes the results of the work. (a) For the covering entry of this conference, please see ITRD abstract no. E204151.