The Akashi Kaikyō Bridge is a suspension bridge, which links the city of Kobe on the Japanese mainland of Honshu to Iwaya on Awaji Island. It crosses the busy Akashi Strait (Akashi Kaikyō in Japanese) as part of the Honshu-Shikoku Highway.
Carriessix lanes of roadway
CrossesAkashi Strait
LocaleAwaji Island and Kobe
Other name(s)Pearl bridge
Maintained byHonshu-Shikoku Bridge Authority
Characteristics
DesignSuspension bridge
Total length3,911 metres (12,831 ft; 2.430 mi)
Height282.8 metres (928 ft) (pylons)
Longest span1,991 metres (6,532 ft; 1.237 mi)
Clearance below65.72 metres (215.6 ft)
History
DesignerSatoshi Kashima
Construction begin1988
Construction end1998
OpenedApril 5, 1998
Statistics
Toll¥2,300
Akashi Kaikyō Bridge is located in Japan
Akashi Kaikyō Bridge
Location in Japan
Since its completion in 1998,the bridge has had the longest central span of any suspension bridge in the world,[2] at 1,991 metres (6,532 ft; 1.237 mi).
It is one of the key links of the Honshū-Shikoku Bridge Project, which created three routes across the Inland Sea.
History
Before the Akashi Kaikyō Bridge was built, ferries carried passengers across the Akashi Strait in Japan. This dangerous waterway often experiences severe storms, and in 1955 two ferries sank in the strait during a storm, killing 168 people. The ensuing shock and public outrage convinced the Japanese government to develop plans for a suspension bridge to cross the strait. The original plan called for a mixed railway-road bridge, but when construction on the bridge began in April 1988, the construction was restricted to road only, with six lanes. Actual construction did not begin until May 1988, and the bridge was opened for traffic on April 5, 1998.[3]
Structure
Main supporting towers
The bridge has three spans. The central span is 1,991 m (6,532 ft; 1.237 mi),[1] and the two other sections are each 960 m (3,150 ft; 0.60 mi). The bridge is 3,911 m (12,831 ft; 2.430 mi) long overall. The two towers were originally 1,990 m (6,530 ft; 1.24 mi) apart, but the Great Hanshin earthquake on January 17, 1995, moved the towers so much (only the towers had been erected at the time) that the span had to be increased by 1 m (3.3 ft).
The bridge was designed with a two hinged stiffening girder system, allowing the structure to withstand winds of 286 kilometres per hour (178 mph), earthquakes measuring up to magnitude 8.5, and harsh sea currents. The bridge also contains tuned mass dampers that are designed to operate at the resonance frequency of the bridge to dampen forces. The two main supporting towers rise 282.8 m (928 ft) above sea level 112 centimetres (44 in) in diameter।
The Akashi-Kaikyo bridge has a total of 1,737 illumination lights: 1,084 for the main cables, 116 for the main towers, 405 for the girders and 132 for the anchorages. On the main cables three high light discharged tubes are mounted in the colors red, green and blue. The RGB model and computer technology make for a variety of combinations. 28 patterns are used for occasions as national or regional holidays, memorial days or festivities।
Cost
The total cost is estimated at 500 billion yen; it is expected to be repaid by charging drivers a toll to cross the bridge. The toll is 2,300 yen and the bridge is used by approximately 23,000 cars per day. At 2,300 yen/car annual revenue would equal 19.5 billion yen.