What Does The New Austrian Method Of Tunnelling Involve Coursework

What Does The New Austrian Method Of Tunnelling Involve Coursework What Does The New Austrian Method Of Tunnelling Involve â€" Coursework Example > NATM initials stand for the New Austrian Tunneling Method. This method can also be referred to as the sequential excavation method (SEM). This is a popular method of modern tunnel design and construction evident in various projects carried out globally especially in the 21st century where mega structures have been constructed. Tunnel is defined as an underground mode passage dug below the surface of a landmass such as a hill or below a water surface such as a river. NATM technique falls under the class of drill and blast approaches of a tunnel construction. Figure: A tunnel This tunnel construction technique was first practiced in the 1960s with its proprietors being Ladisclaus Von Rabcewicz, Franz Pacher and Leopold Muller who managed to fully undertake projects using this particular technique as from 1957 to the late 1965 in the eastern European country of Austria. This particular method of tunnel construction and design is generally an improvement of the old Austrian tunneling technique approach. The major advantage of this technique of tunnel design and excavation is the economic advantage brought about by the existence of the geological strengths of the surrounding rock masses that actually helps in stabilizing the tunnel hence preventing the tunnel from any threat of collapse. Any collapse of the tunnel would lead to loss of life, property and introduce new construction costs since a new alternative to the construction must be undertaken. NATM has not only helped but also revolutionized modernized tunneling industry. New Austrian Tunneling Method generally takes into account the principles of the ultimate behavior of the surrounding rock masses under the loading conditions and the regular monitoring of performance of the underground construction processes during the construction exercise. It is a design process whereby you do provide essential support based on the ground conditions observed during the course of construction. Therefore this constructi on technique does not take into account a specific set of excavation and support techniques. It can be referred as a dynamic method of construction that changes its set of excavation and support principles based on the needs that arise. To note is that the New Austrian Tunneling Method has a total of seven principles namely; How to exploit the strengths of the native rock masses. The level of exploitation of the native rock masses definitely relies on the inherent strengths of the immediate surrounding mass of rock that is being considered and preserved to be the main component of the tunnel support. Engineers must note primary support is as a result of the surrounding rock mass and hence the rock mass must be excavated in an excellent manner to ensure the rock mass supports itself. Shortcrete protection. This can be defined as a process carried out to ensure that loosening, excessive rock deformations are minimized. This goal is achieved through the application of a thin layer of shortcrete after the face of the advance in the tunnel. Measurements and perquisite monitoring. Any deformations deemed potential are carefully monitored and rapid appropriate solutions undertaken. This tunneling technique requires use of modern high tech measuring instruments that are installed either on the ground or lining of the tunnel to observe any movements. If any movements are observed, additional supports are introduced to avert the threat of collapse. Any collapse means an increase in the total cost of the project and may even lead to loss of life. Flexible supports. Flexible forms of supports are usually introduced in the tunnel for support purposes. The flexible forms of supports may take the forms of rock bolts, steel ribs and even the wire mesh. This is done because the primary lining in the tunnel is only a thin layer and offers a minimal support. Closure of inverts. This is a crucial task undertaken mainly on the soft grounds with the aim of creating a load bearin g ring since it engages the inherent strengths of the immediate rock masses that do surround the tunnel. Contractual arrangements. Since the New Austrian Tunneling Method is normally based on the monitored measurements, changes in the construction methods are only possible if the well defined contractual system enables them. Rock mass classification. Since the rock masses range from the hard to soft rocks, it is necessary to classify them so that appropriate supports are designed and installed in the tunnels depending on the strengths of the immediate rock masses. This mechanism of the rock mass classification helps the tunnel construction engineer to avoid economic wastes that may arise from the unnecessary supports installations.