The International Information Center for Structural Engineers

It was April 4, 2017, when the work of tunneling machine Bertha was complete, breaking through into her disassembly pit and marking the end of the 1.75-mile long State Route 99 (SR 99) tunnel beneath Seattle. Now, the Washington State Department of Transportation released a drone video that shows the ongoing construction work from end-to-end inside the tunnel.

The Fehmarnbelt fixed link in the Baltic Sea will connect the Danish island of Lolland with Germany's Fehmarn island and is expected to boost transportation between central Europe and Scandinavia. Spanning 17.6 km, it will be by far the world’s longest road and rail immersed tube tunnel (IMT), comprising of a four-lane motorway and a double-track railway. The Fehmarnbelt link will cut journeys across the sea from 45 minutes to about 10 by car and 7 by train.

The first major combined bridge and tunnel sea-crossing project in China is the Hong Kong-Zhuhai-Macau Bridge project. Consisting of three cable-stayed bridges and one 6-km sea crossing tunnel, it will have a total length of 55 km. It will be the world’s longest sea bridge and will link three cities in China's Pearl River Delta — creating one mega-city of 42 million people and slashing travel time between Hong Kong and Chinese city Zhuhai from three hours to just 30 minutes. 

The tunnel will become a double-decker highway, scheduled to open in 2019

An ultra-modern underwater road tunnel in Istanbul is taking place and it will be launched in late 2016.

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  • Date occured Friday, 09 October 2015
Monday, 13 July 2015 11:53

The Longest Underwater Tunnel

The underwater tunnel is a huge project with a cost at around 36 billion US dollars, with a length twice as long as the Channel Tunnel is and it will be built in the most dangerous earthquake zones in Asia. When the tunnel is completed, the Dalian tunnel will be the longest undersea tunnel in the world.

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  • Date occured Monday, 13 July 2015

Slated at $10 billion, construction on the Fehmarn Belt Fixed Link could start as early as this year. At 11 miles long, the completed project will be the longest immersed tunnel in the world. It will run beneath the Baltic Sea and connect Denmark to Germany between the islands of Lolland and Fehmarn. Long in the planning, the bill finally giving the project the green light passed its first reading in the Danish Parliament this month. Construction could be completed as early as 2024.

Passengers flying out of Toronto’s Billy Bishop Airport have been accustomed to a unique additional step to reaching their gate when trying to catch a flight. Instead of being dropped off in front of the airport and walking inside to receive one’s boarding pass and go through security, travelers flying through Billy Bishop Airport must take a 90-second ferry ride across Lake Ontario to reach their gate. Billy Bishop Airport is located on an island in Lake Ontario, located two miles from the downtown area. While many passengers enjoy the ferry ride, others have complained that the quarter-hourly crossings cause a lot of stress for passengers trying to make their flight. 

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  • Date occured Tuesday, 06 January 2015

This week marks a milestone in the Elizabeth River Tunnel project in Virginia. The project is one of the largest infrastructure projects occurring in the U.S. right now. It will place a two lane tunnel next to an existing tunnel connecting Norfolk and Portsmouth, Virginia and thus double the tunnels capacity and reduce commute times. SKW Contractors team, a joint venture between Skanska, Kiewit, and Weeks Marine, are overseeing the public-private partnership project and are responsible for submersing eleven 16,000-ton hollow concrete elements into a special trench at the bottom of the Elizabeth River.

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  • Date occured Tuesday, 14 October 2014
Wednesday, 30 July 2014 10:52

UPDATE: Bertha’s Repair Further Delayed

Repairing the tunnel-boring Bertha hit more delays this past week when it was announced the deep access pit that is being built to reach the front side of Bertha would be delayed by a month. Crews need more time to grind and chisel through concrete so the 120-foot deep vault in front of Bertha will be completed in August instead of July as originally planned. Chris Dixon, project director for Seattle Tunnel Partners, believes Bertha will still be fully repaired by March because the repairs had a two-month cushion added to the schedule. While Seattle Tunnel Partners is confident that the machine will be ready to complete the remaining 8,200 feet of tunneling needed for the Alaska Way Viaduct Replacement Tunnel project on time, Washington Department of Transportation is not as optimistic.

Additional Info

  • Date occured Wednesday, 30 July 2014
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