|
Buttress Dam
A buttress dam or hollow dam is a dam with a solid, water-tight upstream side that is supported at intervals on the downstream side by a series of buttresses or supports. The dam wall may be straight or curved. Most buttress dams are made of reinforced concrete and are heavy, pushing the dam into the ground. Water pushes against the dam, but the buttresses are inflexible and prevent the dam from falling over. Buttress or hollow gravity dams were originally built to retain water for irrigation or mining in areas of scarce or expensive resources but cheap labour. A buttress dam is a good choice in wide valleys where solid rock is rare. As designs have become more sophisticated, the virtues and weaknesses of buttress dams have become apparent. The Romans were the first to use buttresses to increase the stability of a dam wall. Buttress dams of slab concrete construction became popular in the United States in the early 20th Century with the patented process of Norwegian-American civil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buttresses
A buttress is an architectural structure built against or projecting from a wall which serves to support or reinforce the wall. Buttresses are fairly common on more ancient buildings, as a means of providing support to act against the lateral (sideways) forces arising out of inadequately braced roof structures. The term ''counterfort'' can be synonymous with buttress and is often used when referring to dams, retaining walls and other structures holding back earth. Early examples of buttresses are found on the Eanna Temple (ancient Uruk), dating to as early as the 4th millennium BC. Terminology In addition to flying and ordinary buttresses, brick and masonry buttresses that support wall corners can be classified according to their ground plan. A clasping or clamped buttress has an L shaped ground plan surrounding the corner, an angled buttress has two buttresses meeting at the corner, a setback buttress is similar to an angled buttress but the buttresses are set back from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nils F
Nils is a Scandinavian given name, a chiefly Norwegian, Danish, Swedish and Latvian variant of Niels, cognate to Nicholas. People and animals with the given name * Nils Bergström (born 1985), Swedish ice hockey player *Nils Björk (1898–1989), Swedish Army lieutenant general *Nils Dacke (died 1543), Swedish rebel * Nils-Joel Englund (1907–1995), Swedish cross-country skier *Nils Ericson (1802–1870), Swedish inventor and engineer *Nils Frahm (born 1982), German pianist and producer * Nils Frykdahl, American musician * Nils Gründer (born 1997), German politician * Nils Hald (1897–1963), Norwegian actor * Nils Haßfurther (born 1999), German basketball player * Nils-Göran Holmqvist (born 1943), Swedish politician * Nils Kreicbergs (born 1996), Latvian handball player *Nils Liedholm (1922–2007), Swedish footballer and coach *Nils Lofgren (born 1951), American musician * Nils Lorens Sjöberg (1754-1822), Swedish officer and poet *Nils Mittmann (born 1979), German basketbal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Library Of Congress
The Library of Congress (LOC) is the research library that officially serves the United States Congress and is the ''de facto'' national library of the United States. It is the oldest federal cultural institution in the country. The library is housed in three buildings on Capitol Hill in Washington, D.C.; it also maintains a conservation center in Culpeper, Virginia. The library's functions are overseen by the Librarian of Congress, and its buildings are maintained by the Architect of the Capitol. The Library of Congress is one of the largest libraries in the world. Its "collections are universal, not limited by subject, format, or national boundary, and include research materials from all parts of the world and in more than 470 languages." Congress moved to Washington, D.C., in 1800 after holding sessions for eleven years in the temporary national capitals in New York City and Philadelphia. In both cities, members of the U.S. Congress had access to the sizable collec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roselend Dam
The Roselend Dam is an arch-buttress dam located east of Beaufort in the Savoie department of the Rhône-Alpes region in south-eastern France. It is located just west and below the Cormet de Roselend mountain pass. The dam was designed by Coyne et Bellier and construction began in 1955. The reservoir began to fill in 1960, the power station was operational in 1961 and the dam complete in 1962. It was constructed for the primary purpose of hydroelectric power generation and supports the 546 MW La Bâthie Power Station. Design and operation The dam has a maximum height of and a length of . It is wide at its crest and wide at its base. The dam has a structural volume of . Its reservoir, Lac de Roselend, can store of water and has a surface area of . Directly over the river bed is the dam's concrete arch with a radius. Flanking it on either side are concrete buttresses supporting the dam wall. Water from the dam is transferred west via a long penstock to the underground power ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Check Dam
A steel check dam A check dam is a small, sometimes temporary, dam constructed across a swale, drainage ditch, or waterway to counteract erosion by reducing water flow velocity. Check dams themselves are not a type of new technology; rather, they are an ancient technique dating from the second century A.D. Check dams are typically, though not always, implemented in a system of several dams situated at regular intervals across the area of interest. Function A check dam placed in the ditch, swale, or channel interrupts the flow of water and flattens the gradient of the channel, thereby reducing the velocity. In turn, this obstruction induces infiltration and reduces eroding. They can be used not only to slow flow velocity but also to distribute flows across a swale to avoid preferential paths and guide flows toward vegetation. Although some sedimentation may result behind the dam, check dams do not primarily function as sediment-trapping devices. For instance, on the Grali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buttress Dams
A buttress is an architectural structure built against or projecting from a wall which serves to support or reinforce the wall. Buttresses are fairly common on more ancient buildings, as a means of providing support to act against the lateral (sideways) forces arising out of inadequately braced roof structures. The term ''counterfort'' can be synonymous with buttress and is often used when referring to dams, retaining walls and other structures holding back earth. Early examples of buttresses are found on the Eanna Temple (ancient Uruk), dating to as early as the 4th millennium BC. Terminology In addition to flying and ordinary buttresses, brick and masonry buttresses that support wall corners can be classified according to their ground plan. A clasping or clamped buttress has an L shaped ground plan surrounding the corner, an angled buttress has two buttresses meeting at the corner, a setback buttress is similar to an angled buttress but the buttresses are set back from the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dams By Type
A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect or store water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees (also known as dikes) are used to manage or prevent water flow into specific land regions. The earliest known dam is the Jawa Dam in Jordan, dating to 3,000 BC. The word ''dam'' can be traced back to Middle English, and before that, from Middle Dutch, as seen in the names of many old cities, such as Amsterdam and Rotterdam. History Ancient dams Early dam building took place in Mesopotamia and the Middle East. Dams were used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravity Dams
A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only the weight of the material and its resistance against the foundation to oppose the horizontal pressure of water pushing against it. Gravity dams are designed so that each section of the dam is stable and independent of any other dam section. Characteristics Gravity dams generally require stiff rock foundations of high bearing strength (slightly weathered to fresh), although in rare cases, they have been built on soil foundations. The bearing strength of the foundation limits the allowable position of the resultant force, influencing the overall stability. Also, the stiff nature of the gravity dam structure is unforgiving to differential foundation settlement, which can induce cracking of the dam structure. Gravity dams provide some advantages over embankment dams, the main advantage being that they can tolerate minor over-topping flows without damage, as the conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concrete Buildings And Structures
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminum combined. Globally, the ready-mix concrete industry, the largest segment of the concrete market, is projected to exceed $600 billion in revenue by 2025. This widespread use results in a number of environmental impacts. Most notably, the production process for cement produces large volumes of greenhouse gas emissions, leading to net 8% of global emissions. Other environmental concerns include widespread illegal sand mining, impacts on the surrounding environment such as increased surface runoff or urban heat island effect, and potential public health implications from toxic ingredients. Significant research and development is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
