Read part 1 here.
Mega projects: an update
Third Bosphorus Bridge
After some delays and postponements, construction of the Yavuz Sultan Selim Bridge, which is located north of the two existing suspension bridges, is due for completion in December of this year. It will not only relieve traffic problems in Istanbul, it will also considerably ease traffic flows on the two existing suspension bridges. The new bridge, said to be the world’s eighth longest suspension bridge, has a 1408 m long central span and a 58 m wide deck. It will carry eight traffic lanes and two railway lines running in the middle. The deck, which has a reinforced concrete back span and metal central span, is supported by a hybrid suspension system comprising 176 stay cables made up of parallel strands and 2 x 2420 m long suspension cables holding 34 pairs of vertical hangers supporting the central section of the deck. These are being supplied by Freyssinet (part of the Soletanche Freyssinet VINCI Construction Group). Construction is being carried out by a consortium of the Turkish company IC Içtas and the Italian company Astaldi.
In all, some 290 000 m3 of ready-mix concrete was required for the 322 m high towers and 430 000 m3 for the North Marmara Highway. The cement used in the concrete, which was supplied by Akçansa, is claimed to be resistant against any kind of physical and chemical attack and will allow the concrete to last the project’s anticipated 100-year lifespan. The special sliding formwork and ACS self-climbing formwork for the huge A-shaped piers, considered to be among the highest in the world, was supplied by the company PERI, working for IC Içtas/Astaldi, and shell construction contractor, Hyundai Engineering & Construction/SK Engineering & Construction J.V.
A special challenge on the project was the need to pump concrete for the 4 x 322 m towers. Consultations between Akcansa and the pump specialist Schwing concluded that three powerful stationary concrete pumps, as well as a large supply of pumping lines working at a maximum high pressure of 200 bars, would do the job.
Istanbul’s Third Airport
In February, Turkey’s then Prime Minister, Ahmet Davutoglu announced that this controversial airport, which is located 35 km from the centre of Istanbul on a 7650 ha site close to the Black Sea, will be opened on 29 October 2017. Construction began in 2014 and the first phase of the project is expected to cost e11 billion. A Turkish consortium, led by Limak Holding AS, won the US$29 billion tender in 2013. The other members of the consortium are Cengiz Holding AS, Kolin Insaat, Mapa AS and Kalyon Group. When completed it will be one of the world’s busiest airports, with some 150 million passengers passing through its four terminal buildings. Atatük’s International Airport is expected to close in 2021.
Eurasia Tunnel Project
The opening of this undersea twin-deck tunnel connecting the Asian and European sides of Istanbul has had its opening rescheduled after progress in construction proved faster than planned. Construction began in January 2014 and it was due to be completed in August 2017; the new opening date is now December 2016. A 14.6 km link project between the Kazlicesme and Goztepe regions of Istanbul, including the 5.4 km tunnel, was designed to address Istanbul’s increasing traffic problems. The travel time between the two regions is expected to be reduced from 100 mins to just 15 mins.
Izmit Bay Crossing
This suspension bridge, reported to be the fourth longest in the world, is located at the eastern end of the Sea of Marmara close to Izmit and about 50 km southeast of Istanbul. The Danish consultant COWI was awarded the contract for the detailed design in cooperation with the Japanese contractor IHI. The centre span is 1550 m between 250 m high steel pylons. The overall construction required 85 000 t of steel and about 125 000 m3 of concrete. The bridge is expected to be completed in 2017 at a cost of US$1 billion, and is part of a highway project that will significantly reduce the travel time between Istanbul and the city of Izmir.
The proposed canal will link the Black Sea with the Sea of Marmara and is expected to cost in excess of US$10 billion. Six bridges will be built along the canal in addition to a new city of 500 000 inhabitants. If all goes to plan it could be completed by 2023 to coincide with the anniversary of the founding of the Turkish Republic.
This is part two of a three-part article written by Paul Maxwell-Cook for World Cement’s September issue and abridged for the website. Subscribers can read the full issue by signing in, and can also catch up on-the-go via our new app for Apple and Android. Non-subscribers can access a preview of the September 2015 issue here.
Read the article online at: https://www.worldcement.com/europe-cis/04092015/turkey-challenging-times-part-2-493/