Road tunnel under the Bosporus

By Agence France-Presse in Istanbul | China Daily USA | Updated: 2016-12-21 07:14

Earth dug in the project enough to fill 788 Olympic pools, while the iron used could build 10 Eiffel Towers

Turkish President Recep Tayyip Erdogan was scheduled to open the first road tunnel underneath the Bosporus Strait in Istanbul on Tuesday, the latest project completed in his plan of transforming the country's infrastructure.

Turkey in October 2013 opened the Marmaray rail tunnel underneath the iconic waterway, the first link beneath the waters that divide Europe and Asia.

But from Tuesday it will be possible for the first time to drive underneath the Bosporus due to a project aimed at relieving congestion in the traffic-clogged Turkish mega city.

'Earthquake proof'

The tunnel required an investment of $1.25 billion, including loans of $960 million, and will reduce driving time for the route from up to 2 hours to 15 minutes.

It was built by a consortium consisting of private Turkish construction company Yapi Merkezi and South Korea's SK Group.

The project comprises a 5.4-kilometer tunnel, with the portion beneath the Bosporus 3.4 km long.

The two-story tunnel was built with a special tunnel boring machine which had a daily progress speed of 8-10 meters on average.

According to the designers, the earth dug in the project would be enough to fill 788 Olympic pools, the cement poured would fill 18 stadiums, while the iron used could build 10 Eiffel Towers.

With Istanbul lying on an active seismic zone, the tunnel has been designed to withstand a magnitude-7.5 earthquake.

It would be undamaged even if Istanbul saw a once-in-500-year earthquake. And the tunnel could resume operation "with slight maintenance works" in the event of a once-in-2,500-year earthquake.

Turkish Transport Minister Ahmet Arslan said that it had been a "huge challenge" to build the tunnel at a depth of 106 meters under the seabed.

He said the authorities planned to build a third tunnel under the Bosporus that would have three storeys and carry both cars and trains.

"I think the Avrasya tunnel will hugely ease the lives of the residents of Istanbul," Arslan said. "But we are not just going to stop there."