Submerged Floating Tunnel in Turkey

Istanbul is a metropolis where cultural and historical profits need to be kept and where modern railway amenities have to be fixed to abate the impact of public conveyance and boost the quantity, dependability and amenity of the transportation systems.
Connecting contradictory shores of a lake, sea or watercourse has continually been only of the dominant undertakings to be featured close to Civil Engineering, it being a fundamental need for the development of the areas surrounding a waterway. Nowadays, this problem is still topical and of great importance, as it is proved by the severa large infrastructures which have been built or planned to be constructed in the last years all over the world, such as, for instance the Channel Tunnel, linking the shores of France with the ones of the United Kingdom, the Immersed Tunnel under construction in the Bosporus Strait (Turkey) or the Suspension Bridge designed to connect Calabria and Sicily in the Messina Strait (Italy). Many  additional  significant  and  obtrusive  cases could be mentioned,  nevertheless  the  said  ones  doubtlessly  represent  the  nearly  innovative cases of the structural solutions which are traditionally  nearly  extensively  victimized to connection regions shared close to the vicinity of waterways:  Cable  Supported  Bridges (i.e. Suspension or Cable stayed Bridges), Underground  Tunnels  and Immersed  Tunnels. Possible waterway crossing solutions Marmaray is an exclusive planet-category project and a centre viewpoint of Turkey’s dictated rill investment plan. It encapsulates construction, dispatch and completion of an upgrading of 63 kilometers of the rail process over the metropolitan regions on both sides of Istanbul strait and the railroad subway of 14 kilometers below Boshphorus. This meaningful base project will provide a seamless high-capacity commuter rail system, an inter-city passenger service and a freight connection between Europe and Asia. The Gebze-Halkali segment is a part of the Ankara–Istanbul corridor and will serve the transportation for not only the city of Istanbul and its hinterland, but also for the whole of Turkey. The basic stage of the propose, the segment below the Istanbul strait has been opened for revenue service on October 29, 2013, the 90th day of the initiation of the Republic of Turkey. The tunnel marks the centerpiece of one of the biggest transport infrastructure projects in the world.The contract includes the design, supply, installation, tests and commissioning of the Trainguard Futur 1300 Level 1 ERTMS and Trainguard Sirius CBTC equipment; a new signaling system including Trackguard WESTRACE Mk II electronic interlocking; train detection systems (jointless track circuits and axle counters); LED wayside signals; Controlguide Rail 9000 centralised traffic control (CTC) and the telecommunication and SCADA systems for the entire project. The contract also includes maintenance for two years with an option to extend it to a further five years. The state of the art technical solution offered by Siemens Rail Automation is all proven technology and includes the ERTMS solution that has been recently installed in the new Ankara-Konya high- speed line plus the Trainguard Sirius CBTC system currently in operation in Madrid Metro and in Singapore Downtown Line, also under execution in three of the Sao Paulo commuter lines of the Sao Paulo commuter network CPTM, in Caracas Metro and in Singapore Downtown Line. In terms of infrastructure, the existing double track network will be replaced by a two-way triple track international gauge system. The new third track will be equipped with ERTMS Level 1 system and will be used for operating mainline intercity trains. The double track will be used for mass transit commuter trains Marmaray, a unique world-class project The Marmaray project, a core element of Turkey’s ambitious rail investment plan, includes the design, execution and completion of an upgrading of 63 kilometers of the commuter rail system through the metropolitan areas on both sides of Istanbul strait plus the construction of a railway tunnel of 14 kilometers under the Bosphorus. and will be equipped both with CBTC system for passenger service and ERTMS Level 1 for freight transportation.At the crossroads of two continents, Istanbul is connected 119 by two bridges over the Bosphorus to cope with the transportation of people and freight. The Bosphorus Bridge was constructed in 1973, and the Fatih Sultan Mehmet Bridge was constructed in 1988. Whereas the former has been used for urban car and bus traffic, the latter has been serving both urban car and bus traffic, and international and national heavy goods vehicles (HGVs) as a part of the Trans European Network. Although Istanbul has had runway connections for more than a hundred years, the trips from one continent to the other are interrupted by the Bosphorus Strait. Foreseeing the potential of a subway going underneath the Bosphorus Strait that would provide continuous transportation between two continents, Turkish authorities offered the Marmaray Project. The Marmaray Project is the first project in the world that connects two continents by railway through an undersea tunnel. The Marmaray Project presents a modern and continuous suburban railway with high passenger capacity by connecting the Asian and European sides of Istanbul under Bosphorus. The underground part of the railway has a length of 13.6 km, and it includes the immersed tube tunnel, the bored tunnels, and the cut and cover tunnel structures. With these characteristics, the Marmaray Project is the most significant transportation project in Turkey thus far and is among the greatest transportation infrastructure projects in the world.Rail railways in both broadsides of Istanbul Strait will be to each other through a railway tunnel connection under the Istanbul Strait. The line goes underground at Yedikule, continues through the Yenikapı and Sirkeci new underground stations, passes under the Istanbul Strait, connects to the Üsküdar new underground station and emerges at Sögütlüçesme. The full upgraded and modern railway system will be near 76 km. The leading structures and systems; consist of the the immersed tube tunnel, bored tunnels, cut-and-cover tunnels, at - grade structures, three new underground stations, 37 surface stations (renovation and upgrading), operations control centre, yards, workshops, maintenance facilities, upgrading of existing tracks including a new third track on ground, completely new electrical and mechanical systems and procurement of modern railway vehicles. The concept of a line shaft below the Istanbul Strait was first elevated in 1860. Nevertheless, where the subway below the Istanbul Strait crosses the deepest divisions of the Strait, the aged-fashioned methods would not let the dig to be on or below the seabed, and then the construction demonstrated a "floating" sort of underpass situated on pillars constructed on the seabed.The Marmaray Project provides a full upgrading of the existing commuter rail system in Istanbul, connecting Halkalı on the European side with Gebze on the Asian side with an uninterrupted, modern, high capacity commuter rail system.Alignment of the Marmaray ProjectWhen introducing major infrastructure Projects such as the Marmaray Project, it is important to realise that it will influence not only the daily traffic pattern of Istanbul, but will also influence the development of the city and the region.The most important objectives are to: a) provide a long-term solution to the current urban transport problems of Istanbul, b) relieve existing operational problems on mainline railway services, c) provide a direct railway connection between Asia and Europe, d) increase capacity, reliability, accessibility, punctuality and safety on the commuter rail services, e) reduce travel time and increase comfort for a large number of commuter rail passengers, f) provide uninterrupted passenger and freight transportation across the Istanbul Strait, g) reduce air pollution that results from exhaust gasses, thereby improving the air quality of Istanbul, h) reduce airborne traffic noise in the centre of Istanbul, andi) reduce adverse effects on historical buildings and heritage sites by offering an alternative to car transport in the historical centre of Istanbul.The Marmaray Project offers many special challenges of which the most important ones are: - The immersed tunnel under the Istanbul Strait will be the deepest built so far, with its deepest point some 58 m under the water surface.- The Istanbul region will most likely experience a seismic event of up to 7.5 magnitude during the lifetime of the Project. - The geotechnical conditions of the Istanbul Strait are of such nature, that the connections between the bored tunnels and the immersed tunnel constitute a special challenge when it comes to seismic conditions. - The ultimate capacity of the commuter system will be not less than 75,000 passengers per hour per direction. This creates special requirements for the safety of people in the tunnels and deep stations. - The marine Works are carried out in very deep water in a water channel through which more than 50,000 ships pass every year and across which a vast number of ferries and passenger boats travel backwards and forwards. - The immersion operations are carried out in the stratified currents of the Istanbul Strait, where the upper current velocity reaches up to 5 knots. - The deep stations and tunnels are constructed in an area where civilization can be traced back more than 8,000 years. Therefore preservation and rescuing of Historical Heritage is a special focus point.The method that will be used in the Marmaray Project to rood the Istanbul Strait - the immersed tube tunnel technique - has been developed since late in the 19th century. The first submerged tubing subway ever exist was constructed in North America for sewer purposes in 1894. The first tunnels for traffic purposes constructed using this technique were also built in the United States. . In Europe, Holland was the first country to adopt the technique, and the Maas Tunnel in Rotterdam was opened in 1942. In 1999, a treaty between the Republic of Turkey and the Japanese Bank for International Cooperation (JBIC) was signed. This loan agreement forms the basis for the funding of the Istanbul Strait Crossing portion of the Project, which represents some 35% of the costs for the entire railway project.The following figures give approximate information regarding the project:Total length: 76.3 km European side: 19.3 km Asian side: 43.4 km Immersed tube tunnel: 1.4 km Bored tunnel: 9.8 km Cut-and-cover and open cut: 2.4 km Maximum Depth of immersed tube tunnel: 56 m Number of stations: Existing stations to be upgraded/rebuilt: 37 New underground stations: 3Taking the problems posed by the heavy traffic on highways of Istanbul into consideration, it was designed an IMT system for Istanbul via the Marmaray Project, which will reduce both the money and the time spent for freight transportation in the long run while providing environmental benefits to Istanbul at large. In this IMT system, it was studied both the facility layout problem and the scheduling problem arising in the Ro-La transportation as part of Marmaray. After an exhaustive investigation of existing Ro-La systems from all over the world, we selected the most used Ro-La systems for system design purposes: Oekombi (OE), which is the system in Austria; Modalohr (MO), which is the system in France; and Eurotunnel (EU), which is between England and France.The layout problem directly affects the scheduling problem, so both of these problems should be analyzed and solved simultaneously. Eventually, the performance of the proposed solution procedures will be determined by the efficiency of the IMT system as a whole.First, layout model includes determining the departments of Ro-La stations based on the systematic layout planning approach. After analyzing the Ro-La system, scientists determined 14 essential departments with their required dimensions for a Ro-La station: platforms, siding, locomotive and wagon parking area, locomotive and wagon warehouse, shuttle parking area, shuttle stop, truck/HGV parking area, truck/HGV warehouse, fire department, social place, office, infrastructure, gas station, and car parking area. Second, we need an activity relationship chart (ARC), which is prepared after evaluating both the physical and the information flows between departments. For the facility 189 layout problem in our IMT system, one of the most important decisions is the design of loading/unloading platforms. Here, they propose using two different loading/ unloading platform structures. The linear platform structure has a switch, and after a train arrives at the station, without requiring a U-curve, it covers the minimum required distance to clear the main line, switches to the other locomotive, and then goes in the other direction to enter the convenient platform for unloading/loading processes. In the circular platform, contrary to all properties of the linear platform, the train goes in the same direction with a U-curve and then enters an empty platform. The train always moves straightforward and performs the load/unload operation at the platform. The major difference between the two platform structures is that, in the linear platform, two locomotives must exist on the train since the train needs to move in both directions, whereas, in the circular platform, only one locomotive per train is sufficient. While the area of the platforms would be the same, the siding rail area of the two platform structures is different. 208 We then develop an iterated improvement algorithm for the facility layout problem that uses ARC and the platform structures as input. The main idea of the algorithm is to start with random initial feasible layouts and then to improve these by successive swapping operations with respect to the departments. To sum everything up, the design of an IMT system in Istanbul will be used in the Marmaray System. The Marmaray System is the first transportation infrastructure where two continents (Europe and Asia) are connected to each other by an undersea railroad tunnel. In order to create a solution to the high traffic density and the related problems faced by Istanbul, the use of Ro-La transportation in the Marmaray Project has been proposed.Construction in a densely populated urban environment is always difficult. It is especially so with the Marmaray Project because of the great number of stake holders involved and also because of Istanbul’s unique history and nature.The Marmaray project is desperately needed to ease the traffic congestion in a metropolis of 13 million inhabitants. Meeting the needs of today and tomorrow without compromising the past or nature involves special challenges. The Marmaray project is a large scale project with interfaces with various stake holders and third parties - a situation which brings with it a real risk of delays and cost increases, and forms one of the major challenges in the project.Work CitedAhrens D. (1997). “Submerged Floating Tunnels – a concept whose time has arrived”, Tunneling and Underground Space Technology, Volume 12, pp. 317-336.Atalay S. Intermodal transportation in 2 Istanbul via Marmaray. november/december 2010Belkaya H. The Marmaray Project: Managing a Large Scale Project with Various Stake Holders. London, U.K,. July 2 - 4, 2008Faggiano B., Landolfo R., Mazzolani F.M. (2005). “The SFT: an innovative solution for waterway strait crossings”. Proceedings of the IABSE Symposium “Structures and Extreme Events”, Lisbon, Portugal, September 14-17.Giulio Martire. The Development Of Submerged Floating Tunnels As An Innovative Solution For Waterway Crossings. Marmaray all set to cross the Bosphorus. Tunnelling & Trenchless Construction. Focus On Greece & Turkey. July/August 2007Martire G. (2007). “Submerged Floating Tunnel performance evaluation”, Master Degree Thesis in Structural and Geotechnical Engineering, University of Naples “Federico II”.Marmaray project Crossing the Bosphorus with cutting-edge-technology. Siemens AG Infrastructure & Cities Sector Mobility and Logistics Division Nonnendammallee. Berlin, Germany.Marmaray Project – Turkey. Sisgeowww.sisgeo.com/uploads/schede/marmaray.pdfSaveur J., Grantz W. (1997). “Structural Design Of Immersed tunnel”, Tunneling.