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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 tunneling method, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
München Marienplatz Tunnelerweiterung
Munich is the capital and most populous city of Bavaria, Germany. As of 30 November 2024, its population was 1,604,384, making it the third-largest city in Germany after Berlin and Hamburg. Munich is the largest city in Germany that is not a state of its own. It ranks as the 11th-largest city in the European Union. The metropolitan area has around 3 million inhabitants, and the broader Munich Metropolitan Region is home to about 6.2 million people. It is the List of EU metropolitan regions by GDP#2021 ranking of top four German metropolitan regions, third largest metropolitan region by GDP in the European Union. Munich is located on the river Isar north of the Alps. It is the seat of the Upper Bavaria, Upper Bavarian administrative region. With 4,500 people per km2, Munich is Germany's most densely populated municipality. It is also the second-largest city in the Bavarian language, Bavarian dialect area after Vienna. The first record of Munich dates to 1158. The city ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapid Transit
Rapid transit or mass rapid transit (MRT) or heavy rail, commonly referred to as metro, is a type of high-capacity public transport that is generally built in urban areas. A grade separation, grade separated rapid transit line below ground surface through a tunnel can be regionally called a subway, tube, metro or underground. They are sometimes grade-separated on elevated railways, in which case some are referred to as el trains – short for "elevated" – or skytrains. Rapid transit systems are usually electric railway, electric railways, that unlike buses or trams operate on an exclusive right-of-way (transportation), right-of-way, which cannot be accessed by pedestrians or other vehicles. Modern services on rapid transit systems are provided on designated lines between metro station, stations typically using electric multiple units on railway tracks. Some systems use rubber-tyred metro, guided rubber tires, magnetic levitation (''maglev''), or monorail. The stations typica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HSL-Zuid
The HSL-Zuid (, ), is a 125 kilometre-long (78 mile) High-speed rail in the Netherlands, Dutch high-speed rail line running between the Amsterdam metropolitan area and the Belgium–Netherlands border, Belgian border, with a branch to Breda, North Brabant. Together with the Belgian HSL 4 it forms the Schiphol–Antwerp high-speed railway. Originally scheduled to be in service by 2007, the first public operations began on 7 September 2009, after a ceremony on 6 September. Intercity Direct operates between Amsterdam and Breda, for the time being with conventional Intercity carriages and TRAXX locomotives. On 13 December 2009 Thalys began services from Amsterdam to Paris and Brussels on the HSL-Zuid. On 4 April 2018 the first scheduled Eurostar connected Amsterdam to London via the HSL-Zuid. Talks about a high-speed line between Amsterdam and the Belgian border started under Prime Minister Joop den Uyl (1973–1977); work began during Wim Kok's first term (1998–2002). The Rij ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Switzerland
Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland is geographically divided among the Swiss Plateau, the Swiss Alps, Alps and the Jura Mountains, Jura; the Alps occupy the greater part of the territory, whereas most of the country's Demographics of Switzerland, 9 million people are concentrated on the plateau, which hosts List of cities in Switzerland, its largest cities and economic centres, including Zurich, Geneva, and Lausanne. Switzerland is a federal republic composed of Cantons of Switzerland, 26 cantons, with federal authorities based in Bern. It has four main linguistic and cultural regions: German, French, Italian and Romansh language, Romansh. Although most Swiss are German-speaking, national identity is fairly cohesive, being rooted in a common historical background, shared ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gotthard Base Tunnel
The Gotthard Base Tunnel (GBT; , , ) is a railway tunnel through the Alps in Switzerland. It opened in June 2016 and full service began the following December. With a route length of , it is the world's longest railway and deepest traffic tunnelThe world longest tunnel for transport of people is the Guangzhou Metro Line 3 in China (60 km). Reference: Nic Ulmi"Des trous suisses remplis d'imaginaire" nterview with André Ourednik '' Horizons'', magazine of the Swiss National Science Foundation and the Swiss Academies of Arts and Sciences, number 118, September 2018, pages 22-23. and the first flat, low-level route through the Alps. Located at the heart of the Gotthard axis, it is the third tunnel to connect the cantons of Uri and Ticino, after the Gotthard Tunnel and the Gotthard Road Tunnel. The GBT consists of a large complex with, at its core, two single-track tunnels connecting Erstfeld (Uri) with Bodio (Ticino) and passing below Sedrun (Grisons). It is part of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canton Of Glarus
The canton of Glarus ( ; ; ; ) is a cantons of Switzerland, canton in east-central Switzerland. The capital is Glarus. The population speaks a variety of Alemannic German. The majority of the population (81%) identifies as Christianity in Switzerland, Christian, about evenly split between Swiss Reformed Church, Protestants and Roman Catholicism in Switzerland, Catholics. History According to legend, the inhabitants of the Linth Valley were converted to Christianity in the 6th century by the Hiberno-Scottish mission, Irish monk Fridolin of Säckingen, Saint Fridolin, the founder of Säckingen Abbey in what is now the Germany, German state of Baden-Württemberg. From the 9th century, the area around Glarus was owned by Säckingen Abbey, the town of Glarus being recorded as ''Clarona''. The Alemanni began to settle in the valley in the early 8th century. The Alemannic German language took hold only gradually and was dominant by the 11th century. By 1288, the Habsburgs had claimed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linthal, Glarus
Linthal is a village and former municipality in the municipality of Glarus Süd and canton of Glarus in Switzerland. The village lies near the head of the valley of the Linth river, and at the foot of the Klausen Pass into the canton of Uri. It is the terminus of the railway line that traverses the length of Glarus. History Linthal is first mentioned in 1289 as ''Lintal''. In 1879, Linthal was connected to the Swiss railway network by the opening of the Swiss Northeastern Railway line from Weesen. The road over the Klausen Pass was built between 1895 and 1900. Construction of the Linth–Limmern Power Stations, Linth–Limmern hydro-electric power scheme, in the mountains above Linthal, commenced in 1957, and was fully operational by 1968. In 2011, the municipality of Linthal was merged into the new municipality of Glarus Süd. Geography The village Linthal lies at the head of the valley of the Linth river, at an altitude of approximately . It is surrounded by mountains, incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linth–Limmern Power Stations
The Linth–Limmern Power Stations are a system of hydroelectric power stations located south of Linthal in the canton of Glarus, Switzerland. The system uses five reservoirs and four power stations at steep variations in altitude. Works on the complex began in 1957 with the construction of Lake Limmern Dam and the Mutt, Tierfehd and Linthal Power Stations. The dam was complete in 1963 and the power stations were all operational by 1968, with an installed capacity of 340 MW. In 2009, a 140 MW pumped-storage component between Lake Limmern and Tierfehd Reservoir was commissioned. In 2010, construction began on the Linthal 2015 Project, which included the expansion of Lake Mutt and Tierfehd Reservoir, and the addition of the Limmern Power Station, a 1,000 MW pumped-storage component between Lake Mutt and Lake Limmern. Commissioning of the last unit in Limmern was completed by December 2017, bringing the total installed capacity of the system to 1480 MW. Design and operation The high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Diving
Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving (other), diving, an ambiguous term with several possible meanings, depending on context. Immersion in water and exposure to high ambient pressure have Physiology, physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done. In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Lock
An air lock is a restriction of, or complete stoppage of liquid flow caused by vapour trapped in a high point of a liquid-filled pipe system. The gas, being less dense than the liquid, rises to any high points. This phenomenon is known as vapor lock, or air lock. Flushing the system with high flow or pressures can help move the gas away from the highest point. Also, a tap (or automatic vent valve) can be installed to let the gas out. Air lock problems often occur when one is trying to recommission a system after it has been deliberately (for servicing) or accidentally emptied. Take, for example, a central heating system using a circulating pump to pump water through radiators. When filling such a system, air is trapped in the radiators. This air has to be vented using screw valves built into the radiators. Depending on the pipe layout – if there are any upside down 'U's in the circuit – it will be necessary to vent the highest point(s). Otherwise, air lock may cause waterfa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Table
The water table is the upper surface of the phreatic zone or zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with groundwater, which may be fresh, saline, or brackish, depending on the locality. It can also be simply explained as the depth below which the ground is saturated. The portion above the water table is the vadose zone. It may be visualized as the "surface" of the subsurface materials that are saturated with groundwater in a given vicinity. In coarse soils, the water table settles at the surface where the water Hydraulic head, pressure head is equal to the atmospheric pressure (where gauge pressure = 0). In soils where capillary action is strong, the water table is pulled upward, forming a capillary fringe. The groundwater may be from precipitation or from more distant groundwater flowing into the aquifer. In areas with sufficient precipitation, water infiltrates through pore spaces in the soil, passing through t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eminent Domain
Eminent domain, also known as land acquisition, compulsory purchase, resumption, resumption/compulsory acquisition, or expropriation, is the compulsory acquisition of private property for public use. It does not include the power to take and transfer ownership of private property from one property owner to another private property owner without a valid public purpose. This power can be legislatively delegated by the state to municipalities, government subdivisions, or even to private persons or corporations, when they are authorized to exercise the functions of public character. The most common uses of property taken by eminent domain have been for roads, government buildings and public utility, public utilities. Many railroads were given the right of eminent domain to obtain land or easements in order to build and connect rail networks. In the mid-20th century, a new application of eminent domain was pioneered, in which the government could take the property and transfer it to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
