Sustainability of Natural and Cultural Assets in an Urban Environment: A Responsible Approach to Tunneling Constructions

The Marmaray Project provides a full upgrading of the existing commuter rail system in Istanbul connecting Europe to Asia with an immersed tunnel under the Istanbul Strait, and providing an uninterrupted modern high-capacity new railway system. The Marmaray Project, with a peak hour capacity of 75,000 passengers per direction, is urgently needed to ease traffic congestion in a metropolis of 15 million inhabitants. The immersed tunnel under the Istanbul Strait is the deepest built so far, and the Istanbul region will most likely experience a seismic event of up to M7.5 during the lifetime of the Project. Besides these technical challenges, the Project involves environmental challenges due to the outstanding and unique natural and historical assets of Istanbul. Preservation and rescuing of Historical Heritage forms a particular focus point. The challenge for Istanbul is to help develop a modern city whilst protecting its natural environment and historical heritage.