1.
Viaduct
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A viaduct is a bridge composed of several small spans for crossing a valley, dry or wetland, or forming a flyover. The term viaduct is derived from the Latin via for road and ducere, the ancient Romans did not use the term, it is a modern derivation from an analogy with aqueduct. Like the Roman aqueducts, many early viaducts comprised a series of arches of equal length. Viaducts may span land, water or both, a viaduct is a bridge composed of several small spans for crossing a valley or a gorge. The term is conventional for a flyover as opposed to a flying junction or a rail bridge which crosses one feature. In Romance languages, the word refers to a bridge which spans only land. A bridge spanning water is called ponte, the longest viaduct in antiquity may have been the Pont Serme which crossed wide marshes in southern France. Viaducts are commonly used in cities that are railroad centers, such as Chicago, Atlanta, Birmingham, London. These viaducts cross the railroad yards that are needed for freight trains there. These viaducts keep highway and city street traffic from having to be interrupted by the train traffic. Likewise, some viaducts carry railroads over large valleys, or they carry railroads over cities with many cross-streets, many viaducts over land connect points of similar height in a landscape, usually by bridging a river valley or other eroded opening in an otherwise flat area. Often such valleys had roads descending either side that become inadequate for the traffic load, such bridges also lend themselves for use by rail traffic, which requires straighter and flatter routes. Some viaducts have more than one deck, such that one deck has vehicular traffic, others were built to span settled areas, crossing over roads beneath—the reason for many viaducts in London. Viaducts over water use of islands or successive arches. The Millau Viaduct is a cable-stayed road-bridge that spans the valley of the River Tarn near Millau in southern France and it was formally dedicated on 14 December 2004 and opened to traffic two days later. The viaduct Danyang–Kunshan Grand Bridge in China is the longest bridge in the according to Guinness World Records as of 2011. Where a viaduct is built across land rather than water, the space below the arches may be used for such as car parking, vehicle repairs, light industry, bars. In the United Kingdom, many lines in urban areas have been constructed on viaducts
2.
Lumber
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Lumber, or timber is wood that has been processed into beams and planks, a stage in the process of wood production. Lumber may also refer to currently un-needed furniture, as in Lumber room, or an awkward gait, ultimately derived from the look of unfashionable, Lumber may be supplied either rough-sawn, or surfaced on one or more of its faces. Besides pulpwood, rough lumber is the raw material for furniture-making and it is available in many species, usually hardwoods, but it is also readily available in softwoods, such as white pine and red pine, because of their low cost. Lumber is mainly used for structural purposes but has other uses as well. It is classified more commonly as a softwood than as a hardwood, in Australia, Ireland, New Zealand and Britain, the term timber describes sawn wood products, such as floor boards. In the United States and Canada, generally timber describes standing or felled trees, before they are milled into boards, Timber there also describes sawn lumber not less than 5 inches in its smallest dimension. The latter includes the often partly finished lumber used in timber-frame construction, remanufactured lumber is the result of secondary or tertiary processing/cutting of previously milled lumber. Specifically, it is cut for industrial or wood-packaging use. Lumber is cut by ripsaw or resaw to create dimensions that are not usually processed by a primary sawmill, resawing is the splitting of 1-inch through 12-inch hardwood or softwood lumber into two or more thinner pieces of full-length boards. For example, splitting a ten-foot 2×4 into two ten-foot 1×4s is considered resawing, structural lumber may also be produced from recycled plastic and new plastic stock. Its introduction has been opposed by the forestry industry. Blending fiberglass in plastic lumber enhances its strength, durability, logs are converted into timber by being sawn, hewn, or split. Sawing with a rip saw is the most common method, because sawing allows logs of lower quality, with grain and large knots. There are various types of sawing, Plain sawn —A log sawn through without adjusting the position of the log, quarter sawn and rift sawn—These terms have been confused in history but generally mean lumber sawn so the annual rings are reasonably perpendicular to the sides of the lumber. Boxed heart—The pith remains within the piece with some allowance for exposure, heart center—the center core of a log. Free of heart center —A side-cut timber without any pith, free of knots —No knots are present. Dimensional lumber is lumber that is cut to standardized width and depth, carpenters extensively use dimensional lumber in framing wooden buildings. Common sizes include 2×4, 2×6, and 4×4, the length of a board is usually specified separately from the width and depth
3.
Iron
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Iron is a chemical element with symbol Fe and atomic number 26. It is a metal in the first transition series and it is by mass the most common element on Earth, forming much of Earths outer and inner core. It is the fourth most common element in the Earths crust, like the other group 8 elements, ruthenium and osmium, iron exists in a wide range of oxidation states, −2 to +6, although +2 and +3 are the most common. Elemental iron occurs in meteoroids and other low oxygen environments, but is reactive to oxygen, fresh iron surfaces appear lustrous silvery-gray, but oxidize in normal air to give hydrated iron oxides, commonly known as rust. Unlike the metals that form passivating oxide layers, iron oxides occupy more volume than the metal and thus flake off, Iron metal has been used since ancient times, although copper alloys, which have lower melting temperatures, were used even earlier in human history. Pure iron is soft, but is unobtainable by smelting because it is significantly hardened and strengthened by impurities, in particular carbon. A certain proportion of carbon steel, which may be up to 1000 times harder than pure iron. Crude iron metal is produced in blast furnaces, where ore is reduced by coke to pig iron, further refinement with oxygen reduces the carbon content to the correct proportion to make steel. Steels and iron alloys formed with metals are by far the most common industrial metals because they have a great range of desirable properties. Iron chemical compounds have many uses, Iron oxide mixed with aluminium powder can be ignited to create a thermite reaction, used in welding and purifying ores. Iron forms binary compounds with the halogens and the chalcogens, among its organometallic compounds is ferrocene, the first sandwich compound discovered. Iron plays an important role in biology, forming complexes with oxygen in hemoglobin and myoglobin. Iron is also the metal at the site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants. A human male of average height has about 4 grams of iron in his body and this iron is distributed throughout the body in hemoglobin, tissues, muscles, bone marrow, blood proteins, enzymes, ferritin, hemosiderin, and transport in plasma. The mechanical properties of iron and its alloys can be evaluated using a variety of tests, including the Brinell test, Rockwell test, the data on iron is so consistent that it is often used to calibrate measurements or to compare tests. An increase in the content will cause a significant increase in the hardness. Maximum hardness of 65 Rc is achieved with a 0. 6% carbon content, because of the softness of iron, it is much easier to work with than its heavier congeners ruthenium and osmium. Because of its significance for planetary cores, the properties of iron at high pressures and temperatures have also been studied extensively
4.
Steel
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Steel is an alloy of iron and other elements, primarily carbon, that is widely used in construction and other applications because of its high tensile strength and low cost. Steels base metal is iron, which is able to take on two forms, body centered cubic and face centered cubic, depending on its temperature. It is the interaction of those allotropes with the elements, primarily carbon. In the body-centred cubic arrangement, there is an atom in the centre of each cube. Carbon, other elements, and inclusions within iron act as hardening agents that prevent the movement of dislocations that otherwise occur in the lattices of iron atoms. The carbon in steel alloys may contribute up to 2. 1% of its weight. Steels strength compared to pure iron is possible at the expense of irons ductility. With the invention of the Bessemer process in the mid-19th century and this was followed by Siemens-Martin process and then Gilchrist-Thomas process that refined the quality of steel. With their introductions, mild steel replaced wrought iron, further refinements in the process, such as basic oxygen steelmaking, largely replaced earlier methods by further lowering the cost of production and increasing the quality of the product. Today, steel is one of the most common materials in the world and it is a major component in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons. Modern steel is generally identified by various grades defined by assorted standards organizations, the noun steel originates from the Proto-Germanic adjective stakhlijan, which is related to stakhla. The carbon content of steel is between 0. 002% and 2. 1% by weight for plain iron–carbon alloys and these values vary depending on alloying elements such as manganese, chromium, nickel, iron, tungsten, carbon and so on. Basically, steel is an alloy that does not undergo eutectic reaction. In contrast, cast iron does undergo eutectic reaction, too little carbon content leaves iron quite soft, ductile, and weak. Carbon contents higher than those of steel make an alloy, commonly called pig iron, while iron alloyed with carbon is called carbon steel, alloy steel is steel to which other alloying elements have been intentionally added to modify the characteristics of steel. Common alloying elements include, manganese, nickel, chromium, molybdenum, boron, titanium, vanadium, tungsten, cobalt, and niobium. Additional elements are important in steel, phosphorus, sulfur, silicon, and traces of oxygen, nitrogen, and copper. Alloys with a higher than 2. 1% carbon content, depending on other element content, cast iron is not malleable even when hot, but it can be formed by casting as it has a lower melting point than steel and good castability properties
5.
Reinforced concrete
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The reinforcement is usually, though not necessarily, steel reinforcing bars and is usually embedded passively in the concrete before the concrete sets. Reinforcing schemes are designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made of steel, Reinforced concrete may also be permanently stressed, so as to improve the behaviour of the final structure under working loads. In the United States, the most common methods of doing this are known as pre-tensioning and post-tensioning, durability in the concrete environment, irrespective of corrosion or sustained stress for example. François Coignet was a French industrialist of the century, a pioneer in the development of structural. Coignet was the first to use iron-reinforced concrete as a technique for constructing building structures, in 1853 Coignet built the first iron reinforced concrete structure, a four story house at 72 rue Charles Michels in the suburbs of Paris. Coignets descriptions of reinforcing concrete suggests that he did not do it for means of adding strength to the concrete, in 1854, English builder William B. Wilkinson reinforced the concrete roof and floors in the two-storey house he was constructing. His positioning of the reinforcement demonstrated that, unlike his predecessors, in 1877, Monier was granted another patent for a more advanced technique of reinforcing concrete columns and girders with iron rods placed in a grid pattern. Though Monier undoubtedly knew reinforcing concrete would improve its inner cohesion, before 1877 the use of concrete construction, though dating back to the Roman Empire and reintroduced in the mid to late 1800s, was not yet a proven scientific technology. His work played a role in the evolution of concrete construction as a proven. Without Hyatts work, more dangerous trial and error methods would have largely depended on for the advancement in the technology. G. A. Wayss was a German civil engineer and a pioneer of the iron, in 1879 Wayss bought the German rights to Moniers patents and in 1884 started the first commercial use for reinforced concrete in his firm Wayss & Freytag. Up until the 1890s Wayss and his firm greatly contributed to the advancement of Moniers system of reinforcing, ernest L. Ransome was an English-born engineer and early innovator of the reinforced concrete techniques in the end of the 19th century. With the knowledge of reinforced concrete developed during the previous 50 years, ransomes key innovation was to twist the reinforcing steel bar improving bonding with the concrete. Gaining increasing fame from his concrete constructed buildings Ransome was able to build two of the first reinforced concrete bridges in North America, one of the first concrete buildings constructed in the United States, was a private home, designed by William Ward in 1871. The home was designed to be fireproof for his wife, one of the first skyscrapers made with reinforced concrete was the 16-storey Ingalls Building in Cincinnati, constructed in 1904. Many different types of structures and components of structures can be built using reinforced concrete including slabs, walls, beams, columns, foundations, frames, Reinforced concrete can be classified as precast or cast-in-place concrete. Designing and implementing the most efficient floor system is key to creating optimal building structures, small changes in the design of a floor system can have significant impact on material costs, construction schedule, ultimate strength, operating costs, occupancy levels and end use of a building
6.
Falsework
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This usage is specifically called centering. The British Standards of practice for falsework, BS5975,1982, until the turn of the 20th century almost all falsework was constructed from timber. To compensate for shortages in different regions and to rationalize labor and material usage. The major developments include the design of devices, transitions to other spanning beams such as steel pipes or profiles or reusable timber beams. During the same period many different scaffolding systems were being developed around the world and these consisted of welded frames that could be slotted or clipped together to form access or support towers. The reduction in time and complexity led to reduced labor costs. Further developments have made scaffolding systems even easier to use, stronger systems have been introduced that either incorporate horizontal restraints at more levels or use stronger tubes or connections. Materials from which falsework systems are manufactured have also diversified from traditional steel, in the UK, BS5975 gives recommendations for the design and use of falsework on construction sites. It was first introduced by the British Standards Institute in March 1982 and was revised in March 1996. The code is currently under revision again, a copy was released in late 2007. Fabrication, Metalworkers fabricate a falsework section from pipe and beams, erection, A section is lifted to a vertical position with the assistance of two forklift operators. Placement, The section is guided into position by a ground crew, completed Falsework, Decking and some formwork has been added. When the supports are complete, wood beams and plywood or reusable metal forms will be placed, reinforcing and tenon conduits added, after curing and any tenon tensioning, wedges will be removed and forms and falsework disassembled. A certain type of bridge, the suspension bridge, must be supported during construction
7.
Bent (structural)
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A bent in American English is a two-dimensional transverse rigid frame. The term is used for the cross-ways support structures in a trestle. In British English this assembly is called a cross frame, the term bent is probably an archaic past tense of the verb to bind, referring to the way the timbers of a bent are joined together. The Dutch word is bint, the Frisian is bynt, compare this with the term bend for a class of knots. Bents are the blocks that define the overall shape and character of a structure. They do not have any sort of pre-defined configuration in the way that a Pratt truss does. Rather, bents are simply cross-sectional templates of structural members, i. e. rafters, joists, posts, pilings, the term bent is not restricted to any particular material. Bents may be formed of piles, timber framing, steel framing. Bents are generally pre-assembled, either at the timber framing companys shop or at the construction site, after the basic post and beam structure of the frame has been set in place, the bents are then lifted and simply dropped into place one by one by the crane. Next, the workers bring in members, purlins, which tie them together. This process is safe and efficient, as it allows a crew to assemble a large portion of the frame without ever stepping off the ground. This, in turn, minimizes the amount of time that the crew must spend several stories in the air clambering along beams not much wider than their own feet. Barn raising Pike pole Gin pole Timber roof truss Tau Beta Pi — engineering society whose seal incorporates a bent Benson, building the Timber Frame House, The Revival of a Forgotten Art. Glossary Useful terms in the timber framing trade, blog Entry Some good pictures and a short narrative about raising bents
8.
Great Salt Lake
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The Great Salt Lake, located in the northern part of the U. S. state of Utah, is the largest salt water lake in the Western Hemisphere, and the eighth-largest terminal lake in the world. In an average year the lake covers an area of around 1,700 square miles, for instance, in 1963 it reached its lowest recorded size at 950 square miles, but in 1988 the surface area was at the historic high of 3,300 square miles. In terms of area, it is the largest lake in the United States that is not part of the Great Lakes region. The lake is the largest remnant of Lake Bonneville, a prehistoric lake that once covered much of western Utah. The three major tributaries to the lake, the Jordan, Weber, and Bear rivers together deposit around 1.1 million tons of minerals in the each year. As it is endorheic, it has very high salinity, far saltier than seawater, which makes swimming similar to floating and its shallow, warm waters cause frequent, sometimes heavy lake-effect snows from late fall through spring. The Great Salt Lake is a remnant of a larger prehistoric lake called Lake Bonneville. At its greatest extent, Lake Bonneville spanned 22,400 square miles, nearly as large as present-day Lake Michigan, and roughly ten times the area of the Great Salt Lake today. Bonneville reached 923 ft at its deepest point, and covered much of present-day Utah and small portions of Idaho, Lake Bonneville existed until about 16,800 years ago, when a large portion of the lake was released through the Red Rock Pass in Idaho. With the warming climate, the lake began to dry, leaving the Great Salt Lake, Utah Lake, Sevier Lake. While the lake was known by local Native Americans, it entered written history through the records of Silvestre Vélez de Escalante. No name was given to it at the time, and it was not shown on the map by Bernardo Miera y Pacheco, in 1824, it was observed, apparently independently, by Jim Bridger and Etienne Provost. Shortly thereafter other trappers saw it and walked around it, most of the trappers, however, were illiterate and did not record their discoveries. As oral reports of their findings made their way to those who did make records, Escalante had been on the shores of Utah Lake, which he named Laguna Timpanogos. It was the larger of the two lakes that appeared on Mieras map, other cartographers followed his lead and charted Lake Timpanogos as the largest lake in the region. As people came to know of the Great Salt Lake, they interpreted the maps to think that Timpanogos referred to the Great Salt Lake, on some maps the two names were used synonymously. In time Timpanogos was dropped from the maps and its association with Utah Lake was forgotten. Fremont led the first scientific expedition to the lake, but with winter coming on and that happened in 1850 under the leadership of Howard Stansbury
9.
Causeway
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In modern usage, a causeway is a road or railway on top an embankment usually across a broad body of water or wetland. When first used, the word appeared in a such as causey way making clear its derivation from the earlier form causey. This word seems to have come from the source by two different routes. It derives ultimately, from the Latin for heel, calx, anciently, the construction was trodden down, one layer at a time, often by slaves or flocks of sheep. Today, this work is done by machines, the same technique would have been used for road embankments, raised river banks, sea banks and fortification earthworks. The second derivation route is simply the hard, trodden surface of a path, the name by this route came to be applied to a firmly-surfaced road. It is now little-used except in dialect and in the names of roads which were notable for their solidly-made surface. The 1911 Encyclopædia Britannica states causey, a mound or dam, which is derived, through the Norman-French caucie, from the late Latin via calciata, a road stamped firm with the feet. The word is comparable in both meanings with the French chaussée, from a form of which it reached English by way of Norman French. The French adjective, chaussée, carries the meaning of having given a hardened surface. As a noun chaussée is used on the one hand for a metalled carriageway, other languages have a noun with similar dual meaning. The Welsh is relevant here, as it also has a verb, sarnu, a transport corridor that is carried instead on a series of arches, perhaps approaching a bridge, is a viaduct. In the U. S. a short stretch of viaduct is called an overpass, some low causeways across shore waters become inaccessible when covered at high tide. The modern embankment may be constructed within a cofferdam, two parallel steel sheet pile or concrete retaining walls, anchored to each other with steel cables or rods. This construction may also serve as a dyke that keeps two bodies of water apart, such as bodies with a different water level on each side, or with water on one side. This may also be the purpose of a structure, the road providing a hardened crest for the dike. It also provides access for maintenance as well perhaps, as a public service, notable causeways include those that connect Singapore and Malaysia, Bahrain and Saudi Arabia and Venice to the mainland, all of which carry roadways and railways. In the Netherlands there are a number of prominent dykes which also double as causeways, including the Afsluitdijk, Brouwersdam, in Louisiana, two very long bridges, called the Lake Pontchartrain Causeway, stretch across Lake Pontchartrain for almost 38 km, making them the worlds longest bridges
10.
Roller coaster
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A roller coaster is an amusement ride developed for amusement parks and modern theme parks. LaMarcus Adna Thompson obtained a patent regarding roller coasters on January 20,1885, which were out of wood. In essence a specialized railroad system, a roller coaster consists of a track that rises in designed patterns, the track does not necessarily have to be a complete circuit, as shuttle roller coasters demonstrate. Most roller coasters have multiple cars in which passengers sit and are restrained, two or more cars hooked together are called a train. Some roller coasters, notably wild mouse coasters, run with single cars. Built in the 17th century, the slides were built to a height of between 21 and 24 m, consisted of a 50-degree drop, and were reinforced by wooden supports. Some historians say the first roller coaster was built under the orders of Russias Catherine the Great in the Gardens of Oranienbaum in St. Petersburg in the year 1784, other historians believe that the first modern roller coaster was built by the French. The name Russian Mountains to designate a roller coaster is preserved in many Romance languages, however, the Russian term for roller coasters is американские горки, which means American mountains in Russian. In 1827, a company in Summit Hill, Pennsylvania constructed the Mauch Chunk gravity railroad. By the 1850s, the Gravity Road was providing rides to thrill-seekers for 50 cents a ride, Railway companies used similar tracks to provide amusement on days when ridership was low. Using this idea as a basis, LaMarcus Adna Thompson began work on a gravity Switchback Railway that opened at Coney Island in Brooklyn and this track design was soon replaced with an oval complete circuit. In 1885, Phillip Hinkle introduced the first full-circuit coaster with a hill, the Gravity Pleasure Road. Not to be outdone, in 1886 Thompson patented his design of roller coaster that included dark tunnels with painted scenery. Scenic Railways were to be found in amusement parks across the county, by 1919, the first underfriction roller coaster had been developed by John Miller. Soon, roller coasters spread to amusement parks all around the world, perhaps the best known historical roller coaster, Cyclone, was opened at Coney Island in 1927. The Great Depression marked the end of the first golden age of roller coasters and this lasted until 1972, when the Racer was built at Kings Island in Mason, Ohio. Designed by John Allen, the instant success of the Racer began a golden age. In 1959, Disneyland introduced a breakthrough with Matterhorn Bobsleds
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