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Akashi Kaikyō Bridge
Akashi Kaikyō Ō-hashi (明石海峡大橋 ?)
Akashi Kaikyō Bridge from the air.
Other name(s)	Pearl bridge
Carries	6 lanes of roadway
Crosses	Akashi Strait[1]
Locale	Awaji Island and Kobe[1]
Maintained by	Honshū-Shikoku Bridge Authority
Design	Suspension bridge[1]
Total length	3,911 meters (12,831 ft)
Height	282.8 metres (928 ft) (pylons)[1]
Longest span	1,991 meters (6,532 ft)[1]
Clearance below	65.72 meters
Beginning date of construction	1988[1]
Completion date	1998[1]
Opened	April 5, 1998
Toll	¥2,300
Coordinates	34°36′59″N 135°01′13″E / 34.61639°N 135.02028°E / 34.61639; 135.02028Coordinates: 34°36′59″N 135°01′13″E / 34.61639°N 135.02028°E / 34.61639; 135.02028

The Akashi-Kaikyō Bridge (明石海峡大橋, Akashi Kaikyō Ō-hashi ^?), also known as the Pearl Bridge, has the longest central span of any suspension bridge, at 1,991 metres (6,532 ft). It is located in Japan and was completed in 1998^[1]. The bridge links the city of Kobe on the mainland of Honshū to Iwaya on Awaji Island by crossing the busy Akashi Strait. It carries part of the Honshū-Shikoku Highway.

The bridge 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 children. 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 1986, the construction was restricted to road only, with six lanes. Actual construction did not begin until May 1986, and the bridge was opened for traffic on April 5, 1998. The Akashi Strait is an international waterway that necessitated the provision of a 1,500-metre (4,921 ft)-wide shipping lane.

Architecture

The bridge has three spans. The central span is 1,991 m (6,532 ft)^[1], and the two other sections are each 960 m (3,150 ft). The bridge is 3,911 m (12,831 ft) long overall. The central span was originally only 1,990 m (6,529 ft), but the Kobe earthquake on January 17, 1995, moved the two towers sufficiently (only the towers had been erected at the time) so that it had to be increased by 1 m (3.3 ft).^[1]

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 to 8.5 on the Richter scale, and harsh sea currents. The bridge also contains pendulums that are designed to operate at the resonance frequency of the bridge to damp forces. The two main supporting towers rise 298 m (978 ft) above sea level, and the bridge can expand because of heating up to 2 metres (7 ft) over the course of a day. Each anchorage required 350,000 tonnes (340,000 LT; 390,000 ST) of concrete. The steel cables have 300,000 kilometres (190,000 mi) of wire: each cable is 112 centimetres (44 in) in diameter and contains 36,830 strands of wire.^[2][3]

View from water level

Use

The total cost is estimated at ¥500 billion, and is expected to be defrayed by charging commuters a toll to cross the bridge. The toll is ¥2,300 and is used by approximately 23,000 cars/day.^[4]

Nearby attractions

Two parks in proximity of the bridge have been built for tourists, one in Maiko (including a small museum) and one in Asagiri. Both are accessible by the coastal train line.

Photos

At night.	Viewed from an airplane.	View from a tower.	On the roadway
Akashi Kaikyō Bridge	Viewed from the Ōkura Beach Akashi

See also

• Great Seto Bridge
• Honshū-Shikoku Bridge Project
• Kurushima-Kaikyo Bridge
• List of longest suspension bridges

References

External links

• Akashi Kaikyo Bridge in the Structurae database