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, 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 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
Walnut Lane Bridge
The Walnut Lane Bridge is a concrete arch bridge located in Northwest Philadelphia that connects the Germantown and Roxborough neighborhoods across the Wissahickon Creek in Fairmount Park. While drivers may cross the bridge too quickly to notice, the view from underneath the bridge has inspired artists and writers. The design was copied from Pont Adolphe in Luxembourg, the Walnut Lane Bridge was added to the National Register of Historic Places in 1988. Construction began on July 5,1906 and was completed on October 14,1908. Over 40,000 tons of concrete were poured into the falsework. The bridges six spans total 585 ft in length, very little use was made of reinforcing steel, which was scarce at the time. The roadway is 40 ft wide, flanked by 10-foot reinforced-concrete sidewalks, the chief engineer was George S. Webster, assisted by Henry Quimby, both of the Philadelphia Department of Public Works. At the time of its construction, the bridge was the longest and highest concrete bridge in the world.
While $240,000 was originally committed to the project, the rose to nearly $260,000 by completion. The bridge was a product of the City Beautiful Movement in Philadelphia in the early years of the 20th century. It was believed that more beautiful construction techniques could help to reform a corrupt political system within the city, the Philadelphia community members rallied around the construction of the bridge and the opening was highly anticipated by all ages alike. The bridge was opened on October 14,1908 and was dedicated on December 16 of the same year. Students from nearby schools participated in the ceremony by marching toward the middle of the bridge. The ceremony ended with a reception at an inn with the traditional Wissahickon meal of catfish. The Walnut Lane Bridge is often confused with other bridges in Philadelphia that are similar in name, the Walnut Street Bridge crosses the Schuylkill River and connects University City and Center City, Philadelphia. The nearby Wissahickon Memorial Bridge, which connects the East Falls, the Walnut Lane Bridge has a history of tragedies and deaths since construction began in 1906.
In December 1907, the collapsed and sent about 20 workers plunging 150 feet into the Wissahickon Creek. Martin Simpson was listed as the worker to die during the tragedy while Bernard Mers lost an arm
A bridge is a structure built to span physical obstacles without closing the way underneath such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. There are many different designs that each serve a particular purpose, the Oxford English Dictionary traces the origin of the word bridge to an Old English word brycg, of the same meaning. The word can be traced back to Proto-Indo-European *bʰrēw-. The word for the game of the same name has a different origin. The first bridges made by humans were probably spans of cut wooden logs or planks and eventually stones, using a simple support, some early Americans used trees or bamboo poles to cross small caverns or wells to get from one place to another. Dating to the Greek Bronze Age, it is one of the oldest arch bridges still in existence, several intact arched stone bridges from the Hellenistic era can be found in the Peloponnese. The greatest bridge builders of antiquity were the ancient Romans, the Romans built arch bridges and aqueducts that could stand in conditions that would damage or destroy earlier designs.
An example is the Alcántara Bridge, built over the river Tagus, the Romans used cement, which reduced the variation of strength found in natural stone. One type of cement, called pozzolana, consisted of water, sand and mortar bridges were built after the Roman era, as the technology for cement was lost. In India, the Arthashastra treatise by Kautilya mentions the construction of dams, a Mauryan bridge near Girnar was surveyed by James Princep. The bridge was swept away during a flood, and repaired by Puspagupta, the use of stronger bridges using plaited bamboo and iron chain was visible in India by about the 4th century. A number of bridges, both for military and commercial purposes, were constructed by the Mughal administration in India and this bridge is historically significant as it is the worlds oldest open-spandrel stone segmental arch bridge. European segmental arch bridges date back to at least the Alconétar Bridge, rope bridges, a simple type of suspension bridge, were used by the Inca civilization in the Andes mountains of South America, just prior to European colonization in the 16th century.
During the 18th century there were innovations in the design of timber bridges by Hans Ulrich Grubenmann, Johannes Grubenmann. The first book on bridge engineering was written by Hubert Gautier in 1716, a major breakthrough in bridge technology came with the erection of the Iron Bridge in Shropshire, England in 1779. It used cast iron for the first time as arches to cross the river Severn, with the Industrial Revolution in the 19th century, truss systems of wrought iron were developed for larger bridges, but iron does not have the tensile strength to support large loads. With the advent of steel, which has a tensile strength, much larger bridges were built. In 1927 welding pioneer Stefan Bryła designed the first welded bridge in the world
Toulon is a city in southern France and a large military harbour on the Mediterranean coast, with a major French naval base. Located in the Provence-Alpes-Côte-dAzur region, Toulon is the capital of the Var department, the Commune of Toulon has a population of 165,514 people, making it the fifteenth-largest city in France. It is the centre of an area with 559,421 inhabitants. Toulon is the fourth-largest French city on the Mediterranean coast after Marseille, Toulon is an important centre for naval construction, wine making, and the manufacture of aeronautical equipment, maps, tobacco, printing and electronic equipment. The military port of Toulon is the naval centre on Frances Mediterranean coast, home of the French Navy aircraft carrier Charles De Gaulle. The French Mediterranean Fleet is based in Toulon, archaeological excavations, such as those at the Cosquer Cave near Marseilles, show that the coast of Provence was inhabited since at least the Paleolithic era. The Ligurians settled in the beginning in the 4th century BC.
In the 2nd century BC, the residents of Massalia called upon the Romans to help pacify the region. The Romans defeated the Ligurians and began to start their own colonies along the coast, Toulon harbour became a shelter for trading ships, and the name of the town gradually changed from Telo to Tholon and Toulon. Toulon was Christianized in the 5th century, and the first cathedral built and Gratianus of Toulon, according to the Gallia Christiana, were the first bishops of Toulon, but Louis Duchesne gives Augustalis as the first historical bishop. He assisted at councils in 441 and 442 and signed in 449 and 450 the letters addressed to Pope Leo I from the province of Arles, a Saint Cyprian and biographer of St. Cæsarius of Arles, is mentioned as a Bishop of Toulon. His episcopate, begun in 524, had not come to an end in 541, in 1095, a new cathedral was built in the city by Count Gilbert of Provence. As barbarians invaded the region and Roman power crumbled, the town was attacked by pirates. In 1486 Provence became part of France and his Italian campaign failed, and 1497, the rulers of Genoa, who controlled commerce on that part of the Mediterranean, blockaded the new port.
However, a few months the commander of the new fort sold it to the commander of an Army of the Holy Roman Empire, in 1543, Francis I found a surprising new ally in his battle against the Holy Roman Empire. He invited the fleet of Ottoman Admiral Barbarossa to Toulon as part of the Franco-Ottoman alliance, the residents were forced to leave, and the Ottoman sailors occupied the town for the winter. This fleet carried aboard an army of 8,000 infantry and 800 cavalry and its baggage under Thomas of Savoy, king Louis XIV was determined to make France a major sea power. In 1660, his Minister Jean-Baptiste Colbert ordered Sébastien Le Prestre de Vauban to build a new arsenal and to fortify the town
The Passerelle, known as the Luxembourg Viaduct, is a viaduct in Luxembourg City, in southern Luxembourg. Nowadays it runs from the south into the city centre, Ville Haute, carrying traffic across the Pétrusse valley. It is 290m long, with 24 arches, and 45m above the valley floor and it is known as the Old Bridge by people from Luxembourg City. The new bridge in comparison is the Adolphe Bridge, which was built between 1900 and 1903. It was conceived by the engineers Edouard Grenier and Auguste Letellier, history of rail transport in Luxembourg Luxembourg Viaduct at Structurae
International Standard Serial Number
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication. The ISSN is especially helpful in distinguishing between serials with the same title, ISSN are used in ordering, interlibrary loans, and other practices in connection with serial literature. The ISSN system was first drafted as an International Organization for Standardization international standard in 1971, ISO subcommittee TC 46/SC9 is responsible for maintaining the standard. When a serial with the content is published in more than one media type. For example, many serials are published both in print and electronic media, the ISSN system refers to these types as print ISSN and electronic ISSN, respectively. The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers, as an integer number, it can be represented by the first seven digits. The last code digit, which may be 0-9 or an X, is a check digit. Formally, the form of the ISSN code can be expressed as follows, NNNN-NNNC where N is in the set, a digit character.
The ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, for calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, the modulus 11 of the sum must be 0. There is an online ISSN checker that can validate an ISSN, ISSN codes are assigned by a network of ISSN National Centres, usually located at national libraries and coordinated by the ISSN International Centre based in Paris. The International Centre is an organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, at the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept, where ISBNs are assigned to individual books, an ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole.
An ISSN, unlike the ISBN code, is an identifier associated with a serial title. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change, separate ISSNs are needed for serials in different media. Thus, the print and electronic versions of a serial need separate ISSNs. Also, a CD-ROM version and a web version of a serial require different ISSNs since two different media are involved, the same ISSN can be used for different file formats of the same online serial
Trams in Luxembourg
Trams in Luxembourg started operation in 1875 when the first horse trams ran in Luxembourg City along a 10 km line. The original track followed a route from the station through the city centre to Limpertsberg. It was extended to parts of the city until 1930 when the network covered 31 km. Several lines were closed at the beginning of the 1960s as buses replaced the trams, the last tram ran on the line to Beggen on 5 September 1964. The countrys other tram network designated Tramways Intercommunaux du Canton dEsch served Esch-sur-Alzette, Luxembourg is planning to reintroduce trams in the near future, initially from the central station to Kirchberg and to Luxembourg Airport. Work is expected to be completed by 2017 at a total cost of EUR400 million, among other things, it will necessitate considerable redesign work on the Pont Adolphe at the centre of the city. Lucien Lux, Minister of Transport, explained that the initial phase would run from Kirchberg to the Central Station and it would be extended to the station in Hollerich.
Funding was to be shared between the City of Luxembourg and the State, in June 2014, the Chamber of Deputies approved by a 56–3 vote the project to build the tramway. A number of historic trams can be seen at Luxembourg Citys tram, in particular, the museum exhibits two electric trams, two tram coaches, and a replica of a horse tram. There are models and photographs. Association des modélistes ferroviaires de Luxembourg, Les tramways de la ville de Luxembourg, Les chemins de fer luxembourgeois, Vol.5. Bohnert, Dhur, Eck, Rauen, Prosper, De Minettstram, die Geschichte der interkommunalen Trambahnen im Kanton Esch, Düdelingen, Stadtverwaltung und Kulturkommission,1985, history of rail transport in Luxembourg Trams Trams in Europe luxtram. lu
Luxembourg, known as Luxembourg City, is the capital city of the Grand Duchy of Luxembourg, and the countrys most populous commune. The city contains Luxembourg Castle, established by the Franks in the Early Middle Ages, as of January 2016, the commune had a population of 115,227, which was more than three times the population of the countrys second most populous commune. The citys metropolitan population, including that of surrounding communes of Hesperange, Strassen, in 2011, Luxembourg was ranked as having the second highest per capita GDP in the world at $80,119, with the city having developed into a banking and administrative centre. In the 2011 Mercer worldwide survey of 221 cities, Luxembourg was placed first for personal safety while it was ranked 19th for quality of living, in the Roman era, a fortified tower guarded the crossing of two Roman roads that met at the site of Luxembourg city. Siegfried built his castle, named Lucilinburhuc, on the Bock Fiels, in 987, Archbishop Egbert of Trier consecrated five altars in the Church of the Redemption.
At a Roman road intersection near the church, a marketplace appeared around which the city developed, the city, because of its location and natural geography, has through history been a place of strategic military significance. The first fortifications were built as early as the 10th century, by the end of the 12th century, as the city expanded westward around the new St. Nicholas Church, new walls were built that included an area of 5 hectares. In about 1340, under the reign of John the Blind, in 1443, the Burgundians under Philip the Good conquered Luxembourg. Subsequently, the Burgundians, the Spanish, the French, the Spanish again, the Austrians, the French again, in the 17th century, the first casemates were built, Spain built 23 km of tunnels, starting in 1644. These were enlarged under French rule by Marshal Vauban, during the French Revolutionary Wars, the city was occupied by France twice, briefly, in 1792–3, later, after a seven-month siege. After the Luxembourg Crisis, the 1867 Treaty of London required Luxembourg to dismantle the fortifications in Luxembourg City.
Their demolition took sixteen years, cost 1.5 million gold francs, the Prussian garrison was to be withdrawn. When, in 1890, Grand Duke William III died without any heirs, the Grand Duchy passed out of Dutch hands. Despite Luxembourgs best efforts to remain neutral in the First World War, on 30 August, Helmuth von Moltke moved his headquarters to Luxembourg City, closer to his armies in France in preparation for a swift victory. However, the victory never came, and Luxembourg would play host to the German high command for another four years. At the end of the occupation, Luxembourg City was the scene of an attempted communist revolution, on 9 November 1918, communists declared a socialist republic, in 1921, the city limits were greatly expanded. The communes of Eich, Hamm and Rollingergrund were incorporated into Luxembourg City, in 1940, Germany occupied Luxembourg again. Under the occupation, the citys streets all received new, German names
Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power.
The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations.
In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
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 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, beams, foundations, 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