The Record-Setting Akashi-Kaikyo Suspension Bridge
Setting the record for suspension bridges across the world!
In my previous write-up on the Millau Viaduct Bridge, I briefly mentioned the technical challenges of constructing record-setting bridges.
For example, the Millau Viaduct Bridge required A-frame column design with additional reinforcement below to properly handle the stress of thermal expansion.
So while considering ideas for my next write-up, my friend Dave pointed me towards the Akashi-Kaikyo Bridge Project connecting the city of Kobe on the mainland (Japan) to Iwaya on Awaji Island across the Akashi Strait.
The bridge is over two miles long (12,831 ft), making it the longest suspension bridge in the world. Its central span is over a mile long (6532 ft), setting another record for the longest for a suspension bridge in the world. For comparison, the central span of the San Francisco Bay Bridge is approximately a quarter-mile long (2310 ft).
The central span of the bridge contains an observation deck offering breath-taking views of the water below:
The bridge replaces the ferry service across the Akashi Strait, which is susceptible to severe storms and currents. It is designed with a two-hinged stiffening girder system to resist:
- Winds up to 178 mph
- Earthquakes measuring up to 8.5 on the Richter scale
- Year-round sea currents
Finally, here are a couple more facts about the bridge:
- It sits with two main towers (both 978 ft in height) and one record-setting main span.
- Expansion can be up to 7 feet in length over the course of each day.
- A pendulum system operate at the resonance frequency of the bridge to reduce damping forces caused by winds and traffic.
