Tuesday, December 7

Kansai airport: a monstrous construction on a gigantic artificial island

Japan had no space to build its new airport, as virtually the entire island is densely populated. What was the solution? Create an artificial island from scratch to have territory on which to build.

For this, it was chosen the Osaka bay area, one of the most hostile environments in the world due to its extreme weather, in which strong winds hit the bay regularly and earthquakes happen frequently.

Gaining ground from the sea, the first big step

The first challenge, started in 1987, was to gain territory from a sea more than 20 meters deep and a clay soil in the area where they wanted to create the island. To solve this, they had to drain sand from the bottom of the sea.

The island is built on a solid base: clay columns were created that, when crushed, expel the water back into the clay to compact it even more

De NASA/GSFC/MITI/ERSDAC/JAROS, and US/Japan ASTER Science Team – NASA’s Earth Observatory

This is a curious process in which sand is placed at the bottom of the sea and crossed with millions of vertical pipes (columns) that, in turn, also contain sand. After removing the pipes, columns of sand are built.

By building on top of this structure (sand plus sand columns), the weight of the island’s cement compresses the clay, the seawater seeps through the columns and the bottom on which it is supported becomes more stable.

Tetrapods | By Andrzej Otrębski – Own work, CC BY-SA 3.0

Before building the island itself, also it was necessary to build an impressive 11-kilometer-long dike, a huge wall of concrete tetrapods, an engineered solution that manages to contain the force of the sea.

Finally, an island 4 kilometers long by 1 kilometer wide was built. Construction was completed in 1990, to begin in 1991 with the construction of the spectacular terminal featuring mobile joints.

Building an airport on the sea

De lasta29 –Osaka Kansai

They once had the solid foundation and dam to protect it, three mountains were leveled to have enough land to fill the base. More than 180 million cubic meters of land were used, with 80 ships working for three years to dump materials and shape the artificial island.

Renzo Piano, junto a Noriake Okabe, they were the two great architects behind the 1.7 kilometer building they wanted to build. It was designed in the shape of an airplane wing, its main hall measures 30 meters high, and the departure canopy measures 1.7 kilometers long.

From 663highland – Own work, CC BY 2.5

The challenge to build it was that it did not collapse due to the extreme weather of the island. The structure of the building is flexible, through a system of joints around the entire construction.

These boards allow you to literally the building moves in case of earthquake or strong winds, to absorb the impact of meteorological phenomena. Even the 5,000 glass panels in the terminal have these joints, which allow each panel to move individually so as not to break and absorb shocks.

A total of 10,000 workers to build this airport in 3 years, It was completed in 1995. Despite being built against meteorological phenomena, in 2018 Typhoon Jebi managed to completely flood the airport. Despite this, the airport is still alive and operating alongside Tokyo International Airport.