Civil engineering Essay Example | Topics and Well Written Essays - 2000 words

Civil engineering - Essay Example the railroad is completely flat (en.rian.ru, 2011). It was built to integrate the nation into a modern rail network and is a part of the Alp Transit Railway Project which can afford the citizens the ease to travel in a better and faster manner. The tunnel site was filled with hard rocks posing a significant challenge to the excavation staff and causing immense disturbance in the surrounding area (Leung, Zhou, 2006: 153). It is known to be one of the greatest feats of engineering considering the fact that it was built at 4000 feet above sea level, on an uneven route comprising of steep gradients and sharp curves and exposed to dangerous environment which included snow and avalanches. Furthermore it was built under a mountain range which is nearly 8000 to 11000 feet high (Williams, 1968: 176). It took almost fifteen years to construct this spectacular engineering feat, costing billions of dollars. The construction of this tunnel is not only a significant engineering achievement but is also laudable for its major contribution in easing traffic and connecting various areas by enabling road transport at cheaper and faster rate. However, various problems were encountered during and after the construction of this tunnel, which presents a significant opportunity for study, and the same is discussed in the following sections. Figure 1: St. Gotthard Base Tunnel – Geographic location Source: World Records (2011) Geological setting The St. Gotthard Base Tunnel, as mentioned in the previous section is one of the largest tunnels in the world and is constructed in the Alpine mountain range. The construction of a tunnel of this magnitude and length, entails application of special state of the art techniques and technology. The tunnel was divided into five sections depending upon the geological structure of the site. These five sections include: Erstfeld, Amsteg, Sedrun, Faido, and Bodio which were approximately 7.4 km, 11.4 km, 6.8 km, 14.6 km, and 16.6 km in length, re spectively (as shown in Figure 3 below). Boring machines were used in all the sections other than in the Sedrun section, where the conventional blasting technique was used, since the rock formation in that area was highly unstable and could have posed a significant danger (NA, 2011). Figure 2: Geographical Setting Figure 3: Sedrun Tunnel The method applied for tunneling depends largely on the rock type in the area in which the tunnels are being constructed. Thus, it is of utmost significance for the engineers to devise various alternate strategies for tunneling and align the same with the rock types encountered by them on site. Almost 90 per cent of the rock type in the Gotthard Base Tunnel comprises of rock which is suEhrbarble for mining thus, the boring techniques were used in the areas such as Erstfeld, Amsteg, Faido and Bodio and the traditional mining techniques were used to blast the area in the Sedrun section (NA, 2011). Figure : Geological formations – St. Gotthard B ase Tunnel Temperature in the tunnel: Furthermore, the temperature in tunnels is also drastically different and hence must also be taken into consideration. When rock is exposed in the tunnels during excavation, a significant amount of heat is generated depending upon various factors such as the virgin rock temperature i.e. VRT; the thermal properties, the amount of water contained in the rock, the