Marmaray Tunnel in Istanbul
Marmaray Tunnel is actually an intercontinental undersea railway tunnel, crossing Bosporus Strait and connecting Istanbul’s Asian part and European part. It began to be built in 2004 and after several postpones, Marmaray Tunnel had been finished in 2013.
The overall length of project is 13.6 kilometers and about 1.4 kilometers’ are undersea. Marmaray Tunnel is located at 4.6 meters under seabed and 60 meters under sea level. It will have two layers and 4 lanes.
This tunnel is not only the first undersea tunnel connecting Eurasia, but also an important component of New Silk Road from Beijing to London, which helps to promote communication among countries.
The most remarkable of Marmaray Tunnel is to be constructed on a earthquake zone, so it has capacity of withstanding earthquake. Special attention had to be given to design of the bored tunnel lining segments, gaskets and bolted connections.
Self drilling anchor adopts support method of combining sprayed concrete with anchor bolt, adopting multiple corrosion prevention to ensure tunnel’s stability and durability. Decreasing relative displacement between initial support and surrounding rocks, preventing submerge aim to ensure bearing capacity.
As planned, Istanbul will upgrade and reform interurban railways and connect with undersea tunnel, finally a 76-kilometer intercontinental railway will be formed.