ТЕМА: «Разновидности мостов».
Remember singing “London Bridge is falling down ...” in school and at home during those growing up years? One of the most loved nursery rhymes; it is also related to one of the most symbolic English monuments of all times, the London Tower Bridge. Bridges have always been enchanting structures. Creating bridges across vast expanses of water have always been a challenge and an achievement. So, be it the Golden Gate Bridge in San Francisco or the Sydney Harbor Bridge in Sydney, bridges were, are and will be the landmarks of the cities. Each great bridge is distinct in its features and thus a marvel in itself. The basic structure fro the bridge is always based on a few principle factors such as the type of support provided, length of the bridge, proximity to natural disaster zones and of course, the cost. Herein we have described the most common types of bridges.
Different Kinds Of Bridges
Beam Bridges
The simplest types of all bridges, beam bridges are recognized by horizontal beams, supported by two piers at the end. They are the earliest type of bridges. Example of an oldest beam bridge would be a sight, wherein you come across logs of wood kept across a narrow stream, serving as a pathway. Beam bridges normally do not exceed 250 ft in length. The longest beam bridge is Lake Pontchartrain Causeway in the United States, with a total length of 38.35 km. It is made of parts with individual span of 17 m each.
Cantilever Bridges
These bridges are supported as cantilever beams. Cantilever beams are supported on one side only, with the other end being usually free. Most bridges of this kind have two cantilever arms coming from opposite ends and meeting at the center. The largest cantilever bridge is the 549-metre long Quebec Bridge in Canada.
Arch Bridges
Bridges which are arch-shaped fall in this category. They possess abutments on each end, which support the weight of the bridge on them. They are known to exist from a long time. Ancient Greeks have been known to use them. The Sheikh Rashid bin Saeed Crossing in Dubai, scheduled for completion in 2012, will be the longest arch-bridge in the world, once completed
Suspension Bridges
These bridges are suspended from cables, which support the weight of bridge in a webbed form. The earliest suspension bridges were made of ropes or vines covered with pieces of bamboo. In modern days, suspension bridges are suspended using cables hanging from towers supported on caissons or cofferdams. The nearly 4km long, Akashi Kaikyo Bridge in Japan is the longest suspension bridge in the world.
Cable-Stayed Bridges
Though similar to suspension bridges, in a cable-stayed bridge, less cable is required and the towers holding the cables are proportionately shorter. They are never as big as the suspension bridges. The longest cable-stayed bridge is the Sutong Bridge over the Yangtze River in China.
Truss Bridges
These bridges are made of connected elements, which may be stressed by tension, compression or both. The condition of stress depends on the dynamic load on the bridge. A Truss bridge is more economical in construction than any other type due to its efficient use of materials. They have a solid deck and a lattice of pin-jointed or gusset-joined girders for the sides. The world’s largest truss bridge is also the world’s largest cantilever bridge, i.e. The Quebec Bridge.
Словарь-минимум:
swamp [swɔmp]/ 1. 1) болото, топь Syn: marsh , bog , morass 2) трясина financial swamp — финансовая трясина
avine [rə'viːn]/ ущелье; лощина, овраг, ложбина; дефиле Syn: gorge , canyon
shedding 1) отключение, сброс 2) снижение (нагрузки)
terrain [tə'reɪn] 1. 1) местность, территория, район harsh / rough terrain — суровая местность hilly terrain — холмистая местность mountainous terrain — гористая местность smooth terrain — равнинная местность terrain of attack — район наступления Syn: region , district 2) физические особенности местности; топография
mit [ɪ'mɪt ], [iː-]/ 1) испускать, выделять (свет, тепло, запах) ; выбрасывать, извергать (пепел, дым, лаву) to emit smoke — дымить, куриться rays of heat emitted by the warm earth — тёплые волны, идущие от нагретой земли The factory has been emitting black smoke from its chimneys, which is against the law. — Трубы завода до сих пор выбрасывают чёрный дым, что противозаконно. Syn: give off , eject I, throw out 2) издавать (звук) Giant pandas emit a gentle bleat instead of a mighty roar. — Гигантские панды издают нежное блеяние, а не могучий рёв. 3) выпускать (деньги) 4) издавать (указы, официальные документы) 5) излучать
overpass 1. ['əuvəpɑːs] ; ; flyover 1) эстакада; переезд; переход railroad overpass — железнодорожная эстакада pedestrian overpass — пешеходная эстакада 2) путепровод
durable ['djuərəbl]/ 1) надёжный, прочный, стойкий, крепкий a durable pair of boots — прочные ботинки 2) длительный, долговременный, долговечный Syn: permanent , long , protracted 3) длительного пользования
pedestrian [pɪ'destrɪən]/ 1. 1) пешеходный, пеший pedestrian crossing — пешеходный переход Syn: unmounted , foot 2) неинтересный, прозаичный Syn: boring , tedious , prosaic , commonplace , dull , uninspired 2. 1) пешеход Syn: foot passenger 2) участник соревнований по спортивной ходьбе
drawbridge ['drɔːbrɪʤ] подъёмный мост, разводной мост
gorge [gɔːʤ]/ 1. 1) а) горло, глотка, пасть; зоб (у сокола) - raise the gorge б) узкое ущелье, теснина в) затор, нагромождение, завал г) (деталь фортификации) д) желоб (на блоке) Syn: groove
skipping игнорирование; обход; пропуск
Вопросы для самопроверки:
What is a bridge?
What types of bridges do you know?
What is called overpass?
What is called viaduct?
What materials are used in bridge construction?
What is the advantage of drawbridges?
When are pipe bridges used?
What is aqueduct?
САМОСТОЯТЕЛЬНАЯ РАБОТА № 4:
ТЕМА: «:«Баухауз. Высшая школа строительства и художественного конструирования».
“Bauhaus”.
Walter Gropius is one of the outstanding architects and teachers of the 20th
century. His idea was to combine the school of art crafts under the name of the Bauhaus or “House Of Building”.
At the Bauhaus (Weimar), Gropius hoped to find a way to bridge the gap between
the arts and also to unite art and industrial products. Although Gropius was a born
teacher and organizer, it was not easy to launch a school with young men who differed widely in age and abilities.
All students were accepted for a training period. All took a six-month preliminary
course. In this course Gropious introduced students to proportion, scale and colour, and to machines and materials used in mass production.
After completion of a preliminary course the student could join a workshop of his
own choice – ceramics, carpentry, furniture design, metals, weaving or painting. The aim was not only to teach students to use hands but to guide them to an understanding of the tools of the machine age. Gropius, who designed everything from teaspoons to automobile bodies, encouraged students in the direction of fresh honest ideas. He didn’t want students to imitate or become small editions of himself.
After a training period in handwork and design, students had to submit to an
examination by masters of the Bauhaus and by Chamber of Handicrafts. If they passed this they received a diploma and became trade apprentices. They earn a Master’s diploma they had to undergo a period of training in actual building.
Gropius had assembled one of the most distinguished faculties ever housed under
one roof, but the work of his staff excited abuse because it was modern. Rumours and false accusations made it difficult to get the funds needed for the state-supported school.
To tide the Bauhaus over one financial crisis, Gropius sold a valuable family heirloom – linen and table service that had belonged to Napoleon. But all was in vain, the school was to be closed.
Students begged Gropius to reopen the school elsewhere. After newspapers
headlined the rift between him and the government offers came from four cities to make funds available for a bigger, better Bauhaus.
Gropius chose Dessau, a factory town some sixty miles from Berlin. He was
attracted by the beautiful natural surroundings and by the attitude of the courageous, energetic mayor who guaranteed a site and building funds.
Most of the former students moved to Dessau in the spring of 1925 to begin
building activity.
The building program for the new school at Dessau had to meet many different
requirements :
1) the Bauhaus, the school of Design itself;
2) the school of the city of Dessau for continuation courses in the trades;
3) studio and dwelling quarters for students;
4) a private studio for Gropius himself.
The architect’s chief aim was to produce a clear separation of each of these
functions isolating them but bringing them together into efficient interrelation.
The chief accents fell on the Bauhaus the nucleus of the whole school. The
Bauhaus combined laboratories of design with exhibition spaces, classrooms and lecture halls. The laboratories of design were devoted to such various activities as
cabinetmaking, theatrical crafts, dyeing, weaving, printing and metalworking. The
Bauhaus was enclosed by the famous glass curtains. The section containing the pupils’ studio-dormitory rooms rose six stories.
The twenty-eight rooms it contained were intended not only for the students’
residence but for their private work as well. Each room had a small balcony, a concrete slab which jutted out into open space. The students’ building was connected directly with the School of Design through a one-storey wing. A separate wing was reserved for the Dessau trade school. A short two-storey bridge supported by four pillars connected it with the School of Design. This connecting bridge was reserved for administration rooms, meeting places for the masters and students’ councils, the architectural department and the private studio of Gropius.
The Bauhaus had a skeleton of reinforced concrete. The continuous glass curtain
was brought into abrupt juxtaposition with the horizontal ribbons of white curtain wall at the top and bottom of the building. In a bird’s eye view the whole cube seemed like two immense horizontal planes floating over the ground.
The glass curtain was not the limited and marked off transparent area, which
Eiffel had already exploited in the 1878 exhibition, it flowed smoothly around the
building, the corners showing no vertical supporting or binding members. The pillars from which it hung were set behind the glass making the curtain a specimen of pure cantilever construction.
On the day the new Bauhaus – Dessau was opened, Gropius glowed with pride.
The tall dormitory, the reinforced concrete and brick administration building with glass curtain walls, the flat-roofed shop and classroom wings gave striking contrasts, but the building had been unified through passages, bridges and courts. Facilities included auditoriums, library, exhibition hall and student canteen. The house which Gropius had designed for himself stood in a pine wood a few hundred yards away from the main building.
The Bauhaus prospered in its new location. Gropius added a department of
topography and brought in specialists in construction. Because students now lived at the school, rules had to be established. Gropius stood for complete freedom for the individual, but by freedom he did not mean Bohemianism.
Gropius began to be busy with projects again. He studied the possibilities of
prefabrication and became enthusiastic about the use of standardized parts because they could provide higher quality for lower costs. But when he was commissioned to build a large housing unit, he rejected the idea of complete prefabrication with each house exactly like its neighbour.
Around 1927, Gropious found it almost impossible to keep the school functioning
smoothly. Hitler, who was rapidly gaining prestige, disliked modern architecture and called upon Germans to boycott it. Early in 1928 he decided to turn the school over to Hannes Meyer, head of the Department of Architecture and go back to private practice.
He designed Municipal Employment bureau for Dessau, he built the first slablike,
multistorey apartment house in Germany.
Словарь-минимум:
1. craft, n –ремесло
2. gap, n –расхождение
3. launch, v –запускать
4. scale, n – масштаб
5. preliminary, a –] подготовительный
6. ceramics, n –керамика
7. carpentry, n –плотничное дело
8. weaving, n –плетение
9. tool,n –инструмент
10. apprentice, n –ученик
11. distinguish, a –выдающийся
12. heirloom, n –наследство
13. linen, n –бельё
14. rift, n –трещина
15. to isolate, v –изолировать
16. dyeing, n –окраска
17. jut, v –] выступать
18. skeleton, n –каркас
19. abrupt, a –обрывистый
20. juxtapose, v –размещать рядом
21. cantilever, n –консоль
22. humility, n –смиренность
23. slab, n –плита
24. concrete, n – бетон
Вопросы для самопроверки:
Who is Walter Gropius?
Whose was the idea to combine the school of art crafts under the name of the Bauhaus?
What was included to a six-month preliminary course?
What could the student join after completion of a preliminary course?
What had students to do after a training period in handwork and design?
What did the Bauhaus combine?
САМОСТОЯТЕЛЬНАЯ РАБОТА № 5:
ТЕМА: «Прогресс в строительстве туннелей».
PROGRESS IN TUNNEL ENGINEERING
a) When did people begin tunneling? b) Where were the first tunnels built? c) What were tunnels built for?
Tunneling is difficult, expensive and dangerous engineering work. Tunnels are built to provide direct automobile or railway routes through mountain ranges or under rivers. Before the 19th century men had not acquired enough skill in engineering to carry out extensive tunneling. Tunnels, however, were known in ancient times. The first-known tunnel was dug in Babylon in about 2180–60 BC. It passed under the Euphrates River and connected the royal palace with a temple. An early Greek tunnel was completed in 687 BC on the island of Samos as part of an aqueduct system.
The Romans built many aqueduct tunnels throughout their vast empire. Their greatest feat was a 3.5-mile (5.6-kilometer) tunnel to drain Lake Fucino in Italy to create Fucino Basin. Few tunnels were built during the next thousand years. The Moors constructed some irrigation tunnels in Spain during the early 1400s, and in about 1450 a project was begun in the Maritime Alps to link Nice and Genoa. This work, however, was never completed.
By the 17th century tunnels were being constructed for use as canals. During the 19th and 20th centuries the development of railroad and, later, motor-vehicle transportation led to a tremendous expansion worldwide in the number of tunnels and in their length.
Early tunnel-building techniques varied. The Egyptians used copper saws that were capable of cutting soft rock, while the Babylonians constructed masonry tunnels. The Romans tunneled through solid rock by heating the rock face with fire and then rapidly cooling it with water, causing the rock to crack. Tunnel building has always been hazardous, and often hundreds or even thousands of workers died constructing ancient tunnels. The development of modern tunneling technology has also included vast improvements in worker safety.
a) When was the first Alpine tunnel built? b) How is it called? c) What new device was used during tunneling for the first time?
Ever since the early days of civilization in Europe the Alps have been a barrier to the movements of people. The first Alpine tunnel to be constructed was the Mont Cenus tunnel. This great project dates back to 1857. This tunnel is of great technical interest because at that time the only way to get through the rock was to use hand tools. At first the construction advanced very slowly. In fact, if it had continued at the initial pace, it would have taken 5 years to complete the tunnel! However, with compressed air drills and dynamite being introduced, progress was accelerated. Work on the Mont Cenus tunnel started in August 1857 and finished in December 1870.
a) What is the name of the second tunnel cut through the Alps? b) What is the length of the tunnel? c) Why was it dangerous to build tunnels at that time?
The next great and extremely difficult task was the construction of the St. Gotthard tunnel. Italian and Swiss engineers started working on this project in 1872. This tunnel 9.3 miles long was completed 9 years later as compared with 14 years required to make the Mont Cenus tunnel. It should be noted that during the period of construction no less then 800 men lost their lives because of poor ventilation. The only means of ventilating was the compressed air exhausted from the drills. It was so insufficient that the death rate among the workers was extremely great. Needless to say that the ventilation ought to have been much better.
a) What is the longest tunnel cut through the Alps? b) What was done to improve ventilation in the course of tunneling? c) Why was a smaller bore (диаметр тоннеля) adopted?
Both the Mont Cenus and the St. Gotthard tunnels are known to be single tunnels. But when it was decided to bore the Simplon tunnel through the Alps, a different scheme was adopted because geological conditions in this part of the mountains were not simple. The planned length of 12.3 miles was greater than had been done before. According to the project two tunnels were cut, side by side, with transverse galleries connecting them at certain intervals. In this way ventilation was greatly improved and the removal of soil was made much easier. Each tunnel could take only one railway track, so a smaller bore was adopted. Had the tunnel been made the same size as the earlier ones, it might never have been completed. These arrangements made the construction much safer.
CHANNEL TUNNEL
The English Channel (Frenchmen call it “La Manche” – which means ‘the sleeve’) is one of the world's most extraordinary pieces of water. For centuries, the Channel has been Britain's defense against invaders. It has also been the way to the Continent. Sailors know it as perhaps the most dangerous sea channel in Europe. Over the years, people have crossed the tunnel by balloons, canoes, rowing boats, parachutes, water skis and by swimming! The British seem to enjoy using the strange methods of crossing the Channel, using everything from a car to a bed.
Connecting the Isles of Great Britain to mainland Europe by means of a tunnel is an idea that appeared more than 200 years ago. Nevertheless we can name very few projects against which there existed a deeper and more powerful prejudice than the construction of a railway tunnel between Dover and Calais. The objections have been cultural, political and, of course, military. The British government objected to the scheme mainly because they thought that the enemy could easily invade England through such a tunnel.
It can be said that the long history of the Channel Tunnel began in 1802 when a French engineer, Albert Mathieu, according to the order of Napoleon, worked out a project of a tunnel to link France with England. But his project was not carried out, because the war between these countries began in 1803 and the Britons were glad that they were separated from the French by the Channel.
Seventy years later, a British colonel, Ernst Beaumont, began tunneling his way out of his native country using equipment that he designed himself, until he was stopped on grounds of national security. In 1950s a research group was set up to study the possibility of the Channel Tunnel construction. In 1963 this group submitted its report to the British and French governments. But when they were to make a final decision about the Channel Tunnel, the British Government refused from its construction because of financial difficulties.
Only in 1987 the question of the Channel Tunnel was studied afresh by a group of French and British engineers and the work actually began. They agreed to start constructing the Eurotunnel, as it was called, on both English and French coasts. The Tunnel was bored under the sea through a layer of dense chalk which is known to be free of cracks and allows water to penetrate it slowly. Saturday, December 1, 1990 was not an ordinary day in the Channel’s long history. At 11.00 a.m. two miners, one Frenchman and one Englishman, cut through the last few centimeters of chalk separating the UK from Europe. The Tunnel was officially opened for traffic on May 7, 1994.
The Channel Tunnel actually consists of three tunnels: the two running tunnels* and the service tunnel**. Single-track railway lines are laid down in each of the running tunnels. Normally, one of them carries passenger and freight trains from Britain to France and the other carries trains in the opposite direction. If one of the running tunnels is closed for maintenance, the other is used for train movement in both directions. A smaller third tunnel lies between the two train tunnels. It is called the service tunnel. There is a roadway inside it, so maintenance workers and emergency teams can reach any point of the Tunnel system in their road vehicles. The service tunnel is linked to the running tunnels at regular intervals by cross-passages***. In case of emergency or a train breakdown the passengers will leave the train through one of the cross-passages into the service tunnel where road vehicles will evacuate them to a safer place.
The total length of the Tunnel is about 50 km (3.7 km is laid underneath French territory; 9 km is laid underneath British territory and 37 km of the line is constructed under the waters of the English Channel). The electric trains run every 3 minutes during peak hours, providing the carrying capacity of 4,000 vehicles per hour in both directions. A typical passenger shuttle consists of 26 wagons. 13 double-deck carriages are used for carrying cars of average size; another 13 single-deck wagons are used for transporting buses and vans. Freight shuttles consist of 25 single-deck wagons. Each of them is capable of carrying a vehicle weighing up to 44 tons. Two electric locomotives are coupled in front and at the rear of each shuttle.
The time of crossing the Tunnel is 35 minutes, about an hour less than by ferry. Passengers and drivers remain in their vehicles. The gauge of the tunnel railway is standard that’s way the tunnel can be used for international passenger and freight trains.
Original estimate of construction cost was 7.2 billion dollars, but cost to date is 13.1 billion dollars shared between Britain, France and other investors. So far the project has not been quite profitable and still needs more investments.
The Tunnel personnel do its best to make passengers feel comfortable and safe during the crossing. But as it was mentioned by the commercial director of the Tunnel, they still have many serious problems and one of them is security. Nevertheless, the authorities are sure to be able to solve all the problems successfully.
Notes:*running tunnel – эксплуатационный тоннель
**service tunnel – служебныйтоннель
***cross-passage – поперечный переход
Словарь-минимум:
English Channel [ˌɪŋglɪʃ'ʧænl] ; ; Ла-Манш
Running tunnel- железнодорожный туннель
Service tunnel- служебный туннель
single-track railway одноколейная железная дорога
gauge [geɪʤ]/ 1. ; ; gage 1) а) мера, масштаб, размер, калибр - take the gauge of б) шаблон, лекало, эталон Syn: standard в) калибр (в изготовлении оружия) г) номер, толщина (проволоки) д) сортамент проводов е) ширина колеи wide / broad gauge — широкая колея standard gauge — нормальная ширина колеи; стандартная колея narrow gauge — узкая колея ж) колёсная база (у автомобиля)
Вопросы для самопроверки:
When was the first design of the Channel Tunnel proposed?
How many projects had been considered before actual tunneling began?
How many years did it take to construct the English Channel?
Are double-track railway lines laid down in the running tunnels?
What is the service tunnel?
Do electric trains operate in the Channel Tunnel?
What is the time of crossing the Channel Tunnel?
Why can the Tunnel be used for international passenger and freight trains?
САМОСТОЯТЕЛЬНАЯ РАБОТА № 6:
|
