Tunnels and Earthquakes
Istanbul is located some 20 kilometres away from the North Anatolian Fault Zone, which runs from east to west south of the Princees Islands in the Marmaray Sea. The project area is therefore in a location where the risk of a severe earthquake must be taken into account.
Underground structures such as the future tunnels under the Istanbul Strait have been told to be safe places for people in case of earthquake. Several tunnels of similar types around the world have been reported to encounter and have survived earthquakes - of similar magnitude as expected in this region - without major damage. The Kobe tunnel in Japan and the BART tunnel in San Francisco in the USA are examples of how robustly such tunnels can be constructed
On the Marmaray Project, in addition to existing data, additional data will be collected from geological, geotechnical, geophysical, hydrographical and meteorological investigations, and the data will form the basis for the design and construction of the tunnels, using the most modern technologies of civil engineering technology.
The tunnels on this project will accordingly be designed to resist an earthquake of the maximum intensity that may be expected in the area.
Some of the best national and international experts have been involved in the studies and evaluations. Many similar tunnels have already been constructed in earthquake zones in Japan and in the United States, and therefore especially Japanese and American experts have been working closely with scholars and experts from Turkey to develop a set of requirements to be fulfilled in the design of the tunnels.
The Turkish scholars and experts have been concentrating on the definition of the nature of the potential seismic event, and all the knowledge gained here in Turkey and based on historical data - the latest data being collected from the 1999 event in the İzmit Bolu area - have been analysed and used.
The Japanese and American experts have been assisting in this data analysis study, and furthermore they have ensured that all the extensive expertise relating to the design and construction of the tunnels and the seismic and flexible joints in the structures and stations has been incorporated in the requirements to be fulfilled by the Contractors.
In this way, the team of experts forming part of the Avrasyaconsult organisation will be able to advise and assist the Contractors' team of designers and experts to ensure that, should the worst case scenario - a very severe earthquake in the Marmaray region - occur, it will not lead to a catastrophe for people that may be on their way through, or working in, the tunnels.