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Immersed Tunnel
An immersed tube (or immersed tunnel) is a kind of undersea tunnel composed of segments, constructed elsewhere and floated to the tunnel site to be sunk into place and then linked together. They are commonly used for road and rail crossings of rivers, estuaries and sea channels/harbours. Immersed tubes are often used in conjunction with other forms of tunnel at their end, such as a cut and cover or bored tunnel, which is usually necessary to continue the tunnel from near the water's edge to the entrance (portal) at the land surface. Construction The tunnel is made up of separate elements, each prefabricated in a manageable length, then having the ends sealed with bulkheads so they can be floated. At the same time, the corresponding parts of the path of the tunnel are prepared, with a trench on the bottom of the channel being dredged and graded to fine tolerances to support the elements. The next stage is to place the elements into place, each towed to the final location, in mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undersea Tunnel
An underwater tunnel is a tunnel which is partly or wholly constructed under the sea or a river. They are often used where building a bridge or operating a ferry link is unviable, or to provide competition or relief for existing bridges or ferry links.Sullivan, WalterProgress In Technology Revives Interest In Great Tunnels New York Times, June 24, 1986. Retrieved 15 August 2010. While short tunnels are often road tunnels which may admit motorized traffic, unmotorized traffic or both, concerns with ventilation lead to the longest tunnels (such as the Channel Tunnel or the Seikan Tunnel) being railway electrification systems, electrified rail tunnels. Types of tunnel Various methods are used to construct underwater tunnels, including an immersed tube and a submerged floating tunnel. The immersed tube method involves steel tube segments that are positioned in a trench in the sea floor and joined together. The trench is then covered and the water pumped from the tunnel. Submerged flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oakland, California
Oakland is a city in the East Bay region of the San Francisco Bay Area in the U.S. state of California. It is the county seat and most populous city in Alameda County, California, Alameda County, with a population of 440,646 in 2020. A major West Coast of the United States, West Coast port, Oakland is the most populous city in the East Bay, the third most populous city in the Bay Area, and the eighth most populous city in California. It serves as the Bay Area's trade center: the Port of Oakland is the busiest port in Northern California, and the fifth- or sixth-busiest in the United States. A charter city, Oakland was municipal corporation, incorporated on May 4, 1852, in the wake of the state's increasing population due to the California gold rush. Oakland's territory covers what was once a mosaic of California coastal prairie, California coastal terrace prairie, oak woodland, and north coastal scrub. In the late 18th century, it became part of a large ''rancho'' grant in the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after India, representing 17.4% of the world population. China spans the equivalent of five time zones and Borders of China, borders fourteen countries by land across an area of nearly , making it the list of countries and dependencies by area, third-largest country by land area. The country is divided into 33 Province-level divisions of China, province-level divisions: 22 provinces of China, provinces, 5 autonomous regions of China, autonomous regions, 4 direct-administered municipalities of China, municipalities, and 2 semi-autonomous special administrative regions. Beijing is the country's capital, while Shanghai is List of cities in China by population, its most populous city by urban area and largest financial center. Considered one of six ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zhongshan
Zhongshan ( zh, c=中山 ), alternately romanized via Cantonese as Chungshan, is a prefecture-level city in the south of the Pearl River Delta in Guangdong province, China. As of the 2020 census, the whole city with 4,418,060 inhabitants is now part of the Guangzhou–Shenzhen conurbation with 65,565,622 inhabitants. The city-core subdistricts used to be called Shiqi or Shekki ( zh, c=石岐). Zhongshan is one of the few Chinese cities to be named after a person. It was originally named Xiangshan (, "Fragrant Mountain"; Cantonese: ''Heung-saan''), but was renamed in 1925 in honor of Sun Yat-sen, who is known in China as "Sun Zhongshan". Sun was the founding father of the Republic of China who is also regarded positively by the People's Republic. He was born in Cuiheng village in Nanlang Township of what was then Xiangshan County. Names Until 1925, Zhongshan was generally known as Xiangshan or Heung-san (Siangshan) ( zh, c=香山 , l=Fragrant Mountain), in reference to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shenzhen
Shenzhen is a prefecture-level city in the province of Guangdong, China. A Special economic zones of China, special economic zone, it is located on the east bank of the Pearl River (China), Pearl River estuary on the central coast of Guangdong, bordering Hong Kong to the south, Dongguan to the north, Huizhou to the northeast, and Macau to the southwest. With a population of 17.5 million in 2020, Shenzhen is the List of cities in China by population, third most populous city by urban population in China after Shanghai and Beijing. The Port of Shenzhen is the List of busiest container ports, world's fourth busiest container port. Shenzhen roughly follows the administrative boundaries of Bao'an County, which was established in imperial times. After the Opium Wars, the southern portion of Bao'an County was occupied by the British and became part of British Hong Kong, while the village of Shenzhen was next to the border. Shenzhen turned into a city in 1979. In the early 1980s, Chine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fehmarn Belt Fixed Link
The Fehmarn Belt fixed link (, ) or Fehmarn Belt tunnel is an under-construction immersed tunnel, which will connect the Danish island of Lolland with the German island of Fehmarn, crossing the Fehmarn Belt in the Baltic Sea. It will provide a direct link between northern Germany and Lolland, and from there to the Danish island of Zealand and Copenhagen, becoming the world's longest road and rail tunnel. The tunnel will be a major connection between central Europe and Scandinavia. It will shorten the travel time between Lolland and Fehmarn from 45 minutes by ferry (excluding waiting and boarding time) to 10 minutes by car and seven minutes by train. The electrified high-speed rail line will be capable of reaching . The project's cost was initially estimated at €5.5 billion. By 2010, when Denmark and Germany signed the treaty to build the bridge, this had grown to €7.4 billion. The tunnel will be financed by Denmark, which will collect a toll from the crossing. Germany wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transbay Tube
The Transbay Tube is an underwater rail tunnel that carries Bay Area Rapid Transit's four transbay lines under San Francisco Bay between the cities of San Francisco and Oakland, California, Oakland in California. The tube is long, and attaches to twin bored tunnels. The section of rail between the nearest stations (one of which is underground) totals in length. The tube has a maximum depth of below sea level. Built using the immersed tube technique, the Transbay tube was constructed on land in 57 sections, transported to the site, and then submerged and fastened to the bottom – primarily by packing its sides with sand and gravel. Opened in 1974, the tunnel was the final segment of the original BART system to open. All BART lines except the Orange Line (BART), Orange Line operate through the Transbay Tube, making it one of the busiest sections of the system in terms of passenger and train traffic. During peak commute times, over 28,000 passengers per hour travel through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hong Kong–Zhuhai–Macau Bridge
The Hong Kong–Zhuhai–Macau Bridge (HZMB) is a bridge–tunnel system consisting of a series of three cable-stayed bridges, an undersea tunnel, and four artificial islands. It is both the longest sea crossing and the longest Intercontinental and transoceanic fixed links, open-sea fixed link in the world. The HZMB spans the Lingdingyang, Lingding and Jiuzhouyang, Jiuzhou channels, connecting Hong Kong and Macau with Zhuhai—a major city on the Pearl River Delta in China. The HZM Bridge was designed to last for 120 years and cost Renminbi, ¥127 billion (US$18.8 billion) to build. The cost of constructing the #Main Bridge, Main Bridge was estimated at ¥51.1 billion (US$7.56 billion) funded by bank loans and shared among the governments of mainland China, Hong Kong and Macau. Originally set to be opened to traffic in late 2016, the structure was completed on 6 February 2018 and journalists were subsequently taken for a ride over the bridge. On 24 October 2018 the HZMB was o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turkey
Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armenia, Azerbaijan, and Iran to the east; Iraq, Syria, and the Mediterranean Sea to the south; and the Aegean Sea, Greece, and Bulgaria to the west. Turkey is home to over 85 million people; most are ethnic Turkish people, Turks, while ethnic Kurds in Turkey, Kurds are the Minorities in Turkey, largest ethnic minority. Officially Secularism in Turkey, a secular state, Turkey has Islam in Turkey, a Muslim-majority population. Ankara is Turkey's capital and second-largest city. Istanbul is its largest city and economic center. Other major cities include İzmir, Bursa, and Antalya. First inhabited by modern humans during the Late Paleolithic, present-day Turkey was home to List of ancient peoples of Anatolia, various ancient peoples. The Hattians ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Istanbul
Istanbul is the List of largest cities and towns in Turkey, largest city in Turkey, constituting the country's economic, cultural, and historical heart. With Demographics of Istanbul, a population over , it is home to 18% of the Demographics of Turkey, population of Turkey. Istanbul is among the List of European cities by population within city limits, largest cities in Europe and List of cities proper by population, in the world by population. It is a city on two continents; about two-thirds of its population live in Europe and the rest in Asia. Istanbul straddles the Bosphorus—one of the world's busiest waterways—in northwestern Turkey, between the Sea of Marmara and the Black Sea. Its area of is coterminous with Istanbul Province. Istanbul's climate is Mediterranean climate, Mediterranean. The city now known as Istanbul developed to become one of the most significant cities in history. Byzantium was founded on the Sarayburnu promontory by Greek colonisation, Greek col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
