Marmary
Customer
For this project, the Marmaray Project, SGS INTRON worked for different companies. First for Turkeys largest concrete producer OYAK, later when the work for OYAK was finished for the Turkish contractor combination Gama Nurol and the Japanese Contractor Taisei.
Case
In the the Marmaray Project a train link is made between the east side of Istanbul and the west side of Istanbul. The link will cross the Bosphouros the natural border between Europe and Asia. This crossing goes by the name Bosphouros crossing and since it will connect Asia and Europe it is considered a legendary project.
The contract for the project contained very specific demands for the concrete in terms of durability and heat development. Some of the testing in the pre-testing scheme was that complex that it could not be done in Turkey. Therefore specialized firms were needed. This is why OYAK beton asked SGS INTRON for assistance. Eventually this lead to the very unique situation that SGS INTRON was allowed to do the mix design for OYAK but also to act as an independent laboratory with permission of the client and the consultant to the client.
As in many of the mega scale infrastructural projects the Bosphouros crossing was designed as a immersed tube tunnel. The Marmaray project is a 2.5 billion euro project. For these kind of tunnels large whole elements are produced on land and dragged out to the location of the tunnel. There they are sunk off and the elements are connected at the bottom. These elements need to be water tight and therefore without cracks. SGS INTRON has a world wide experience in producing crack free concrete structures and is a world leading firm in this specialism. This is why SGS INTRON was asked to consult and assist the contractors Game Nurol for the immersed tube tunnel and Taisei for the underground stations.
Solution
SGS INTRON designed for the concrete producer OYAK a concrete that met the specifications in the project. SGS INTRON assisted OYAK taking this concrete into production. For the technicians: the Consultant to the client had a strong preference for GGBS based cement, but OYAK preferred a CEM I cement. SGS INTRON was able to design a CEM I based concrete with a low heat production, low chloride diffusion coefficient and high strength.
SGS INTRON developed for the contractors Gama Nural and Taisei several construction plans to avoid cracking in the immersed tube tunnel elements and the underground stations.
Archeolgical excavation site at the Yenakapi station site. One of the stations SGS INTRON worked on. Archeological findings are a major cause for delays in Istanbul