Eiffel Tower.doc

Eiffel Tower 林果慧 090801123Summary:The Eiffel tower which is the most famous building still standing on France after 123 years. It designed by an engineer named Gustave Eiffel. It worthy of us to understand. As we are students for architectural design,Keywords：Eiffel Tower, Eiffel, Design, Origin.The most famous monument in France and the symbol of Paris History On 31 March 1889, the flag was raised on the top of the Eiffel Tower, thus consecrating Gustav Eiffels world-renowned monument, made of 18,038 metal components, 2,500,000 rivets, which took over two years to assemble. In the 108 years since it was built for the World Exhibition, in celebration of the French Revolution, the Eiffel Tower has gained world renown. Over 167 million visitors of all nationalities have climbed the monument made of puddled iron, which has become a symbol of the cultural influence of Paris. In 1996, from its 318.7 meter summit (including the antenna), no less that 5 530 279 visitors enjoyed the view, which extends for up to 80 kilometers in fine weather. Come admire the Eiffel Tower!Origin of the towerThe design of theEiffel Towerwas originated byMaurice Koechlinand mile Nouguier, two senior engineers who worked for the Compagnie des Establissments Eiffel after discussion about a suitable centrepiece for the proposed1889 Exposition Universelle, aWorlds Fairwhich would celebrate the centennial of theFrench Revolution. In May 1884 Koechlin, working at his home, made an outline drawing of their scheme, described by him as a great pylon, consisting of four lattice girders standing apart at the base and coming together at the top, joined together by metal trusses at regular intervals.Initially Eiffel himself showed little enthusiasm, but he did sanction further study of the project, and the two engineers then asked Stephen Sauvestre, the head of companys architectural department, to contribute to the design. Sauvestre added decorative arches to the base, a glass pavilion to the first level and other embellishments. This enhanced version gained Eiffels support, and he bought the rights to the patent on the design which Koechlin, Nougier and Sauvestre had taken out, and the design was exhibited at the Exhibition of Decorative Arts in the autumn of 1884 under the company name. On 30 March 1885 Eiffel read a paper on the project to the Socit des Inginieurs Civils: after discussing the technical problems and emphasising the practical uses of the tower, he finished his talk by saying that the tower would symbolisenot only the art of the modern engineer, but also the century of Industry and Science in which we are living, and for which the way was prepared by the great scientific movement of the eighteenth century and by the Revolution of 1789, to which this monument will be built as an expression of Frances gratitude.Little happened until the beginning of 1886, whenJules Grvywas re-elected as President anddouard Lockroywas appointed as Minister for Trade. A budget for the Exposition was passed and on 1 May Lockroy announced an alteration to the terms of the open competition which was being held for a centerpiece for the exposition, which effectively made the choice of Eiffels design a foregone conclusion: all entries had to include a study for a 300m (980ft) four-sided metal tower on the Champ de Mars. On 12 May a commission was set up to examine Eiffels scheme and its rivals and on 12 June it presented its decision, which was that all the proposals except Eiffels were either impractical or insufficiently worked out. After some debate about the exact site for the tower, a contract was finally signed on 8 January 1887. This was signed by Eiffel acting in his own capacity rather than as the representative of his company, and granted him one and a half million francs toward the construction costs: less than a quarter of the estimated cost of six and a half million francs. Eiffel was to receive all income from the commercial exploitation of the tower during the exhibition and for the following twenty years. Eiffel later established a separate company to manage the tower, putting up half the necessary capital himself.Design of the towerMaterialThewrought ironstructure of the Eiffel Tower weighs 7,300 tonnes, while the entire structure, including non-metal components, is approximately 10,000tonnes. As a demonstration of the economy of design, if the 7,300 tonnes of the metal structure were melted down it would fill the 125-metre-square base to a depth of only 6cm (2.36in), assuming the density of the metal to be 7.8 tonnes per cubic metre. Depending on the ambient temperature, the top of the tower may shift away from the sun by up to 18cm (7.1in) because of thermal expansion of the metal on the side facing the sun.Wind considerationsAt the time the tower was built many people were shocked by its daring shape. Eiffel was criticised for the design and accused of trying to create something artistic, or inartistic according to the viewer, without regard to engineering. Eiffel and his engineers, however, as experienced bridge builders, understood the importance of wind forces and knew that if they were going to build the tallest structure in the world they had to be certain it would withstand the wind. In an interview reported in the newspaperLe Temps, Eiffel said:Now to what phenomenon did I give primary concern in designing the Tower? It waswind resistance. Well then! I hold that the curvature of the monuments four outer edges, which is as mathematical calculation dictated it should be will give a great impression of strength and beauty, for it will reveal to the eyes of the observer the boldness of the design as a whole. Researchers have found that Eiffel used empirical and graphical methods accounting for the effects of wind rather than a specific mathematical formula. Careful examination of the tower shows a basically exponential shape; actually two different exponentials, the lower section overdesigned to ensure resistance to wind forces. Several mathematical explanations have been proposed over the years for the success of the design; the most recent is described as a nonlinear integral equation based on counterbalancing the wind pressure on any point on the tower with the tension between the construction elements at that point.As a demonstration of the towers effectiveness in wind resistance, it sways only 67cm (23in) in the wind.AccommodationWhen built the first level contained two reataurants, an Anglo-American Bar, and a 250 seat theatre. A 2.6m (8ft6in) promenade ran round the outside.On the second level the French newspaperLe Figarohad an office and a printing press, where a special souvenier edition,Le Figaro de la Tour, was produced. There was also aptisserie.On the third level were laboratories for various experiments and a small apartment reserved forGustave Eiffelto entertain guests. This is now open to the public, complete with period decorations and lifelike models of Gustave and some guests.Engraved namesMain article:List of the 72 names on the Eiffel TowerGustave Eiffel engraved on the tower seventy-two names of French scientists, engineers and other notable people. This engraving was painted over at the beginning of the twentieth century but restored in 19861987 by theSocit Nouvelle dexploitation de la Tour Eiffel, a company contracted to operate business related to the Tower.MaintenanceMaintenance of the tower includes applying 50 to 60tonnes of paint every seven years to protect it from rust. The height of the Eiffel Tower varies by 15cm due to temperature.Aesthetic considerationsIn order to enhance the impression of height, three separate colours of paint are used on the tower, with the darkest on the bottom and the lightest at the top. On occasion the colour of the paint is changed; the tower is currently painted a shade of bronze.On the first floor there are interactive consoles hosting a poll for the colour to use for a future session of painting.The only non-st