- Location: Eastern most of the bridges connecting north of Shikoku Island to the south of Honshu Island across Akashi Strait
- Attraction Type: Bridge, engineering marvel
- Significance: Largest Suspension Bridge in the world
- Best Time to Visit: Any time of the year
- How to Reach: By Kobe-Naruto Highway
- Nearest Airport: Kobe Airport
Akashi Kaikyo Bridge is perhaps the greatest engineering feat of Japan. Completed after ten years in 1996, Akashi Kaikyo Bridge in Japan is the longest suspension bridge in the world. Also called the Pearl Bridge, this is the easternmost of the three bridges connecting Honshu with Shikoku to its south. This 1990 meters span bridge was constructed over Akashi Strait by the Honshu-Shikoku Bridge Authority.
The main span of 1990 meters has got two flanks of 960 meters each on either side. This bridge, constructed of nearly 181,400 tons of steel wire and 1.42 million cubic meters of concrete as its substructure, is hung from two towers of 298 meters above sea level. The bridge also has a shipping lane clearance of 65 meters. The traffic of 1400 ships per day across the 1500 meters Akashi Strait is significantly high.
Withstanding power of the bridge is exceptionally strong. The main towers are constructed on iron wire and concrete substructure that go into the strait having a depth of 110 meters where tidal currents could be as high as 4.5 meters per second. Wind speed in these regions can reach up to 80 meters per second, while earthquakes of magnitude of 8.5 on the Richter scale are not uncommon. Anchorages of 84 meters by 63 meters were constructed on either sides of this bridge. The Honshu anchorage, built of granite layers, is embedded about 61 meters below the sea level, whereas the Awaji anchorage is comprised of steel pipes and earth. The cables used for constructing Japan Akashi Kaikyo Bridge are of 1.12 meter diameter.
To support the construction and design of this Japanese bridge, a number of unique technologies were put to use. Honshu-Shikoku Bridge Authority, in association with Public Works Research Institute, constructed the world’s biggest wind tunnel facility to regulate the wind flow turbulence. Vertical plates are installed at the bottom of the highway deck to enhance flutter speed. For the purpose of cable fabrication and erection, parallel wire strands have been used. Usage of parallel wire strands greatly reduces the possibility of in-spinning of cables, which results in accidents.