1994

Kansai International Airport

Imagine that a densely packed city in Japan needs a new airport. The problem is that the dense packing leaves no space for an airport. One solution might be the Dulles Airport approach used near Washington, DC: build the airport many miles out in the countryside. The problem with that is the inconvenience.

So the engineers in Japan chose a radically different path. With no land available, they decided to make their own by building a massive artificial island in Osaka Bay.

If you stand on the island, it seems impossible that it is artificial. It’s huge, measuring 2.5 miles (4 km) by 1.6 miles (2.5 km) in total extent. Look at Central Park in Manhattan, which is itself massive. Now multiply by three. That’s the size of this island. And then they built it over two miles (3 km) offshore to cut down on noise.

How do engineers build an island like this, in an area on the Ring of Fire well-known for earthquakes? Construction started with a sea wall around the perimeter. Then piles were driven into the clay under the island to stabilize it. Then they started dismantling nearby mountains to fill in the island. The water is about 100 feet (30 meters) deep, meaning they needed 27 million cubic yards (23 million cubic meters) of fill. Bringing in all the fill by barge, it took years to displace the sea.

Engineers didn’t stop there. They also built the world’s longest airport concourse, a train system, and an impressive bridge supporting the train track and highway to connect the island to the land. But one of the most interesting problems they had to solve was the settling. How do you build an incredibly long building on a new island that will definitely settle, and keep the building level? Engineers put a hydraulic cylinder under each column so they could raise each one separately by exactly the right amount.

Kansai International Airport, which opened September 4, 1994, is a great example of audacious engineering and the ability to foresee, mitigate, and solve the myriad problems that the audacity caused. It’s one of the things that makes modern engineering so fascinating.

SEE ALSO Leaning Tower of Pisa (1372), Palm Islands (2006), Earthquake-Safe Buildings (2009).

High-angle view of Kansai International Airport.