Tunnel Construction
Tunnels are dug in types of materials varying from soft clay to hard rock. The method of tunnel construction depends on such factors as the ground conditions, the ground water conditions, the length and diameter of the tunnel drive, the depth of the tunnel, the logistics of supporting the tunnel excavation, the final use and shape of the tunnel and appropriate risk management. Tunnel construction is a subset of underground construction. There are three basic types of tunnel construction in common use: * Cut-and-cover tunnel, constructed in a shallow trench and then covered over. * Bored tunnel, constructed in situ, without removing the ground above. They are usually of circular or horseshoe cross-section. Some concepts of underground mining apply. Modern techniques include Shotcrete used in the New Austrian tunnelling method, use of a tunnel boring machine (TBM) or tunnelling shield. But still tunnels are constructed which are secured with pit props and shoring and then are stein ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  

München Marienplatz Tunnelerweiterung
Munich ( ; german: München ; bar, Minga ) is the capital and most populous city of the German state of Bavaria. With a population of 1,558,395 inhabitants as of 31 July 2020, it is the third-largest city in Germany, after Berlin and Hamburg, and thus the largest which does not constitute its own state, as well as the 11th-largest city in the European Union. The city's metropolitan region is home to 6 million people. Straddling the banks of the River Isar (a tributary of the Danube) north of the Bavarian Alps, Munich is the seat of the Bavarian administrative region of Upper Bavaria, while being the most densely populated municipality in Germany (4,500 people per km2). Munich is the second-largest city in the Bavarian dialect area, after the Austrian capital of Vienna. The city was first mentioned in 1158. Catholic Munich strongly resisted the Reformation and was a political point of divergence during the resulting Thirty Years' War, but remained physically un ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]