|
Log Bridge
A log bridge is a timber bridge that uses logs that fall naturally or are intentionally felled or placed across streams. The first man-made bridges with significant span were probably intentionally felled trees. The use of emplaced logs is now sometimes used in temporary bridges used for logging roads, where a forest tract is to be harvested and the road then abandoned. Such log bridges have a severely limited lifetime due to soil contact and subsequent rot and wood-eating insect infestation. Longer lasting log bridges may be constructed by using treated logs and/or by providing well drained footings National Parks Conference 1915, p. 59. "If we can design the abutment so that no moisture can collect under the logs the life of the bridge is materially increased." of stone or concrete combined with regular maintenance to prevent soil infiltration. This care in construction can be seen in the French bridge illustrated below, which has well locked dry set stone abutments and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alzou (Ouysse)
The Alzou is a short river in the Lot (department), Lot département, southern France, a right tributary of the Ouysse. It is long. It flows through the towns Gramat and Rocamadour, and joins the Ouysse, itself a left tributary of the Dordogne (river), Dordogne, downstream of Rocamadour. The valleys of both the Alzou and the Ouysse are deep limestone canyons. The river once powered the watermill ''moulin du Saut'', whose ruins can be visited on foot. File:Moulin du Saut 1 Stevage.jpg, Inside the ''moulin du Saut'' File:Moulin du Saut 4 Stevage.jpg, An outbuilding of the ''moulin du Saut'' File:Canyon de l'Alzou, entre Gramat et Rocamadour.jpg, View over the Alzou valley References Rivers of France Rivers of Lot (department) Rivers of Occitania (administrative region) {{France-river-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rock (geology)
In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition, and the way in which it is formed. Rocks form the Earth's outer solid layer, the crust, and most of its interior, except for the liquid outer core and pockets of magma in the asthenosphere. The study of rocks involves multiple subdisciplines of geology, including petrology and mineralogy. It may be limited to rocks found on Earth, or it may include planetary geology that studies the rocks of other celestial objects. Rocks are usually grouped into three main groups: igneous rocks, sedimentary rocks and metamorphic rocks. Igneous rocks are formed when magma cools in the Earth's crust, or lava cools on the ground surface or the seabed. Sedimentary rocks are formed by diagenesis and lithification of sediments, which in turn are formed by the weathering, transport, and deposition of existing ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridges By Structural Type
A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually something that is otherwise difficult or impossible to cross. There are many different designs of bridges, each serving a particular purpose and applicable to different situations. Designs of bridges vary depending on factors such as the function of the bridge, the nature of the terrain where the bridge is constructed and anchored, and the material used to make it, and the funds available to build it. The earliest bridges were likely made with fallen trees and stepping stones. The Neolithic people built boardwalk bridges across marshland. The Arkadiko Bridge (dating from the 13th century BC, in the Peloponnese) is one of the oldest arch bridges still in existence and use. Etymology The ''Oxford English Dictionary'' traces the origin of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cantilever Bridge
A cantilever bridge is a bridge built using structures that project horizontally into space, supported on only one end (called cantilevers). For small footbridges, the cantilevers may be simple beam (structure), beams; however, large cantilever bridges designed to handle road or rail traffic use trusses built from structural steel, or box girders built from prestressed concrete. The steel truss cantilever bridge was a major engineering breakthrough when first put into practice, as it can span distances of over , and can be more easily constructed at difficult crossings by virtue of using little or no falsework. Origins Civil engineer, Engineers in the 19th century understood that a bridge that was continuous across multiple supports would distribute the loads among them. This would result in lower stresses in the girder or truss and meant that longer spans could be built. Several 19th-century engineers patented continuous bridges with hinge points mid-span. The use of a hing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tibet
Tibet (; ''Böd''; ) is a region in East Asia, covering much of the Tibetan Plateau and spanning about . It is the traditional homeland of the Tibetan people. Also resident on the plateau are some other ethnic groups such as Monpa people, Monpa, Tamang people, Tamang, Qiang people, Qiang, Sherpa people, Sherpa and Lhoba peoples and now also considerable numbers of Han Chinese and Hui people, Hui settlers. Since Annexation of Tibet by the People's Republic of China, 1951, the entire plateau has been under the administration of the People's Republic of China, a major portion in the Tibet Autonomous Region, and other portions in the Qinghai and Sichuan provinces. Tibet is the highest region on Earth, with an average elevation of . Located in the Himalayas, the highest elevation in Tibet is Mount Everest, Earth's highest mountain, rising 8,848.86 m (29,032 ft) above sea level. The Tibetan Empire emerged in the 7th century. At its height in the 9th century, the Tibet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pacific and Indian Oceans. Its Metropolitan France, metropolitan area extends from the Rhine to the Atlantic Ocean and from the Mediterranean Sea to the English Channel and the North Sea; overseas territories include French Guiana in South America, Saint Pierre and Miquelon in the North Atlantic, the French West Indies, and many islands in Oceania and the Indian Ocean. Due to its several coastal territories, France has the largest exclusive economic zone in the world. France borders Belgium, Luxembourg, Germany, Switzerland, Monaco, Italy, Andorra, and Spain in continental Europe, as well as the Kingdom of the Netherlands, Netherlands, Suriname, and Brazil in the Americas via its overseas territories in French Guiana and Saint Martin (island), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beam Bridge
Beam bridges are the simplest structural forms for bridge spans supported by an abutment or pier at each end. No moments are transferred throughout the support, hence their structural type is known as '' simply supported''. The simplest beam bridge could be a log (see log bridge), a wood plank, or a stone slab (see clapper bridge) laid across a stream. Bridges designed for modern infrastructure will usually be constructed of steel or reinforced concrete, or a combination of both. The concrete elements may be reinforced, prestressed or post-tensioned. Such modern bridges include girder, plate girder, and box girder bridges, all types of beam bridges. Types of construction could include having many beams side by side with a deck across the top of them, to a main beam either side supporting a deck between them. The main beams could be I-beams, trusses, or box girders. They could be half-through, or braced across the top to create a through bridge. Because no moments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slovakia
Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the southwest, and the Czech Republic to the northwest. Slovakia's mostly mountainous territory spans about , with a population of over 5.4 million. The capital and largest city is Bratislava, while the second largest city is Košice. The Slavs arrived in the territory of present-day Slovakia in the fifth and sixth centuries. In the seventh century, they played a significant role in the creation of Samo's Empire. In the ninth century, they established the Principality of Nitra, which was later conquered by the Principality of Moravia to establish Great Moravia. In the 10th century, after the dissolution of Great Moravia, the territory was integrated into the Principality of Hungary, which then became the Kingdom of Hungary in 1000. In 1241 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Switzerland
). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel, St. Gallen a.o.). , coordinates = , largest_city = Zürich , official_languages = , englishmotto = "One for all, all for one" , religion_year = 2020 , religion_ref = , religion = , demonym = , german: Schweizer/Schweizerin, french: Suisse/Suissesse, it, svizzero/svizzera or , rm, Svizzer/Svizra , government_type = Federalism, Federal assembly-independent Directorial system, directorial republic with elements of a direct democracy , leader_title1 = Federal Council (Switzerland), Federal Council , leader_name1 = , leader_title2 = , leader_name2 = Walter Thurnherr , legislature = Fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nisqually River
The Nisqually River is a river in west central Washington in the United States, approximately long. It drains part of the Cascade Range southeast of Tacoma, including the southern slope of Mount Rainier, and empties into the southern end of Puget Sound. Its outlet was designated in 1971 as the Nisqually Delta National Natural Landmark. The Nisqually River forms the Pierce–Lewis county line, as well as the boundary between Pierce and Thurston counties. Course The river rises in southern Mount Rainier National Park, fed by the Nisqually Glacier on the southern side of Mt. Rainier. It flows west through Ashford and Elbe along Route 706. It is then impounded for hydroelectricity by the Alder Dam, completed in 1944, and the LaGrande Dam, completed in 1912 and rebuilt in 1945. They hold back Alder Lake and the inaccessible two-mile long LaGrande Reservoir. Before the construction of the dams, a natural fish barrier prevented anadromous fish from ascending the Nisqually above wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zaire
Zaire (, ), officially the Republic of Zaire (french: République du Zaïre, link=no, ), was a Congolese state from 1971 to 1997 in Central Africa that was previously and is now again known as the Democratic Republic of the Congo. Zaire was, by area, the third-largest country in Africa (after Sudan and Algeria), and the 11th-largest country in the world. With a population of over 23 million inhabitants, Zaire was the most-populous officially Francophone country in Africa, as well as one of the most populous in Africa. The country was a one-party totalitarian military dictatorship, run by Mobutu Sese Seko and his ruling Popular Movement of the Revolution party. Zaire was established following Mobutu's seizure of power in a military coup in 1965, following five years of political upheaval following independence from Belgium known as the Congo Crisis. Zaire had a strongly centralist constitution, and foreign assets were nationalized. The period is sometimes referred to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Papua New Guinea
Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country in Oceania that comprises the eastern half of the island of New Guinea and its offshore islands in Melanesia (a region of the southwestern Pacific Ocean north of Australia). Its capital, located along its southeastern coast, is Port Moresby. The country is the world's third largest island country, with an area of . At the national level, after being ruled by three external powers since 1884, including nearly 60 years of Australian administration starting during World War I, Papua New Guinea established its sovereignty in 1975. It became an independent Commonwealth realm in 1975 with Elizabeth II as its queen. It also became a member of the Commonwealth of Nations in its own right. There are 839 known languages of Papua New Guinea, one of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
