The world's first swing and floating arch bridge is going to appear in the Port of Osaka in the year of 2000. It is a highway double-rib arch bridge accommodated with 6 traffic lanes connecting two reclaimed islands and rests on two hollow steel floating foundations. It is supported horizontally by dolphins and rubber fenders and once in a while can swing around a pivot near an end of the girder after the pivot is inserted and a part of transitional side bridges is jacked up. Comprehensive research works have been conducted including large-scale experiments, simulations and numerical analysis.
The Port of Osaka exists as the mainstay of the physical distribution system and is located in the western end of the delta formed by the River Yodo. Now, an arch movable floating roadway bridge (Fig.l) is under construction to connect two man-made islands of Yumeshima and Maishima across the North Waterway (Fig.2). The floating part has the length of 410 m with the main span length of 280 m as shown by Fig.3. Many engineering problems have been solved for its regular service and the safety, particularly, the dynamic response to the waves, winds and strong earthquakes (Maruyama et al., 1998a). Once in a while the dolphin wall will be rotated and unlock or release the floating part to make it free to move as shown in Fig. 1. At both ends of the floating bridge, it is held still through the clamping walls and fenders at the dolphins as shown in Fig. 4; while the dolphins are fixed to the seabed by piles.
