Structural and Foundation Design of Channel Tunnel - Essay Example

?Channel Tunnel Order No. 745930 Table of contents Introduction 2. Structural Design 3. Foundation Design 4. Others Introduction In 1985, the EuroTunnel was part of a competition and had won the first place for its spectacular design genius. The Euro Tunnel (ET) is a bi-national company comprising of Channel Tunnel Group (UK) and its owner and chief operator of the project France Manche S.A (FR) The Euro Tunnel comprises of 3 tunnels i.e. two used for rail and the third one used for maintenance which allows mixed traffic by way of special ‘shuttles’ that carry cars and national trains. The Service Tunnel Transport System that is used for maintenance is made up of 24 twin – cab, rubber tyred vehicles that travel at a speed of 80kmph. The Transmanche Link (TML) is the contractor who is responsible for the Channel Tunnel design, construction and commissionioning of the project. Design of the Channel Tunnel The design scale was massive and highly intricate and hence it was categorized into five divisions – a) System throughput b) Performance of shuttle trains c) Environment d) Safety and passenger evacuation e) Scenarios and operational procedures The design of the Channel Tunnel included four phases: 1. Development Study 2. Outline Design APS) 3. Definitive Design (APD) 4. Detailed Design (PEO) The design of the project was so intricate and diverse with a huge volume of work and specialties involved that sub-contracts making use of the expertise of major independent companies were accepted. Design teams such as BETU (Tunnel design office) and BETER (Terminal design office) contributed their expertise. 1. Structural design a) The Service Tunnel The Service Tunnel Transportation is designed with 24 rubber-tyred vehicles rolling along at top speed of 80 kph that is electronically guided by cables that are embedded but allows for the maintenance of permanent equipment. These shuttles are 650m in length having a single deck. There are open wagons that are 20m in length, 4 m in width and 5m in height with a load capacity of 44T. It is designed in such a way that special amenity coaches are provided to carry drivers between the locomotive and the HGV wagons. b) The Main Railway Tunnels (RTs) The design comprises of two tunnels 50 km in length and running parallel to each other with a distance of 30m. Each tunnel has a single rail track, overhead catenary, power supply, cooling pipes, two walkways, a drainage system and other auxiliary services. These tourist shuttles are designed with an average capacity of 135 vehicles and a length of 775m. Each end has a loading and unloading wagon and 12 twenty-five meter long carrier wagons that are closed and identical. Special Design Features Rail Signaling System The rail signaling system is so designed so as to ensure safety to passengers, drivers, goods and locomotive behavior. All information is directly relayed within the drivers cabin. It also includes an automatic speed limit to ensure safety. Track System Since this railway is the most heavily trafficked with an average of about 240,000,000 tonnes per year, the design is made to match this output. It has a strong support system made of concrete to last for a minimum of 50 years. The strong framework is made highly tolerant for safety to life and property and is also designed with a rail fastening to allow minor service adjustments for maintenance and changing of components. The design also includes a low aerodynamic resistance that allows airflow under the trains. The tunnels comprise of a non-ballasted track made of concrete consisting of UIC 60kg/lm rail tracks that is mounted on pairs of independent support blocks. The tracks are isolated from the support blocks by nylon clips and rubber ‘O’ ring. Such designing not only lends resilience but also maintains a high level of geometric tolerance. The design also contributes towards increasing speed that is 200km/h for TGVs through trains, while shuttles go at 160 km/h. Rolling Stock Rolling Stock comprises of 43 locomotives and 512 wagons that include Tourist Shuttles or Heavy Goods Vehicles (HGV) that can hold a capacity of 2,370 Tonnes. Air suspension contributed to ensuring smooth rides. Traction and Catenary The design includes an overhead catenary system which is 195km in length and is isolated every 1200m within the tunnel. Mechanical sub- systems The design comprises of four remote controlled sub-systems namely, a) normal and supplementary ventilation, b) drainage, c) fire- fighting and d) cooling. a) Normal Ventilation System (NVS) This system is designed in such a way to supply clean and fresh air that maintains the service tunnel as a ‘safe haven for its travellers. There is also a Supplementary Ventilation System that is designed for controlling smoke in case of fires. b) Drainage System The drainage system helps to collect and pump out water in tunnels and is also designed for seepage and storage time of 2 hours when there is an emergency. c) Fire- fighting system Designed to supply water in case of fire within the tunnels. It comprises of 4 tanks connected to a pump house. The network design includes 60 km of pipes having a diameter of 100 to 250 mm that is capable of delivering 120 m3/h. d) Cooling System The cooling system is designed in such a way so as to compensate the heat generated by air friction in the trains and the heat produced by the engines and other electrical equipment. It includes 2 cooling plants and lies within a closed circuit of chilled water that is supplied through pipes with diameters of 400 and 320mm. Control and Communication This system is so designed so as to monitor approximately 26,000 pieces of information through 3 optic fiber cables that have a length of 238 km. The C & C system has a capacity to hold 700 bits of information each second and includes around 2,700 telephone sets, 4,400 loudspeakers and 1,200 fire detectors. The system is also designed to have control over rail/road traffic and other equipment that is fixed through monitoring them and sending information to the information centers. References Channel Tunnel Project Overview www.batisseurs.com The reference you had given me Read More