Exercise 8. Read and translate text B with a dictionary. Write a summary of the text.
Text B.
Many new materials are familiar to us over centuries. We are pretty well acquainted with the advantages and disadvantages of wood. We know that glass is transparent, but in some ways it is rather brittle. Glass has the advantages of cheapness, rigidity and chemical inertness. We are aware that most metals can stand severe handling, but some of them rust. But such materials as plastic materials are not found in nature. Some years ago plastics were little more than laboratory curiosities. Today plastics are conceived in the laboratory of the chemical plant. But plastic is formed by extrusion or injection molding under very high pressure. It can be molded into any desired shape. Organic plastics are divided into two general groups: thermosetting and thermoplastic. The thermosetting group becomes rigid through a chemical change that occurs when heat is applied. These plastic cannot be remolded. The thermoplastic group remains soft at high temperatures and must be cooled before becoming rigid. This group is not used generally as a structural material. Plastics are rapidly becoming important construction materials because of its great variety, strength, durability and lightness. The high strength to weight ratio of some plastic offers big field in the coming age of space travels and rockets. Plastics are light. The same benefits of light weight coupled with good strength and absence of corrosion offer tremendous potential as alternative to traditional building materials. A given volume of polythene weighs less than one-eighth of an equal volume of iron and less than half of the same volume of aluminum. The following of plastics are usually shared by all plastics lightweight, corrosion resistance, electrical and thermal insulation.
Exercise 9. Translate from English into Russian. Define the syntax functions of the underlined words.
1. The Romans also used another structural type.
2. The traditional truss was made up of timbers arranged in triangular shapes or cells.
3. The triangle cannot be changed in shape.
4. It is possible to construct extended figures that are quite strong.
5. Wooden trusses were used in a wide variety of forms for roof construction in Roman buildings and continued to be used during the Middle Ages.
6. It is the broadest wooden span of medieval times.
7. During the nineteenth century, many new forms of trusses were devised, often identified by the name of the engineer who first used them.
8. Wooden trusses were used in a wide variety of forms for roof construction in Roman buildings and continued to be used during the Middle Ages.
|
|
|
Exercise 10. Translate the words :
ферма, древесина, размещать встроенный, искажать, сгибать, крыша, ребро, определять, элемент.
Exercise 11. Note in the texts of this unit:
a. Noun groups
b. Modal verbs
c. Participle II
d. ing-forms
UNIT 8
Exercise 1. Translate the auxiliary words:
before, after, since, rather than, as, that, so that, in order to, because of, because, only, the only, as well as.
Exercise 2. Words to be remembered:
juncture – шов
tube – труба
rotate – вращаться
curve – гнуть, изгибать
handle – переносить, транспортировать
design – проект, проектировать, конструировать
employ – применять
shell – оболочка
edge – край, ребро, грань
stiffen – придавать жесткость
double – двойной
curvature – кривизна, извилина, изгиб
fold (v., n.) – складка, сгиб, сгибать (ся), складывать (ся)
rest on – опираться на
radial – радиальный, веерный
footing ring – опорное кольцо
belt – лента, ремень
wire – проволока
Exercise 3. Read and translate text A.
Text A. SPACE FRAMES AND GEODESIC DOMES
As with the post and lintel or the arch, so the truss can be extended in three dimensions, forming a new type of structure. The truss extended in three dimensions becomes a space frame. It can be supported at any of the junctures of its members permitting large cantilevers, as in McCormick Place, Chicago, 1970-71 by CT F. Murphy and Associates. Substantial three-dimensional trusses, built up of tubes of steel, have a clear span of 342 feet (104.2 meters) and carry the roof slung on their underside.
Just as the arch can be rotated to form a dome, so a truss can be curved in three dimensions to form the "geodesic dome". Like the truss, this is built up of small, light, easily handled steel members.
|
|
|
Shells
Another structural type employs shells. Typically constructed of concrete, shells can be very thick and heavy or extremely thin and light. The American architect Eero Saarinen was interested in shell forms and used a portion of a sphere cut to a triangular plan in his Kresge Auditorium at Massachusetts Institute of Technology.
He devised sweeping, reinforced concrete cantilevered shells for the Trans World Airline Terminal at Idlewild (Kennedy) Airport, New York, 1956-62. The total covered space is 212 by 291 feet (64.6 by 88.7 meters), with enormous cantilevers at the ends of 82 feet (24.9 meters). Typically the edges of such shells are subject to significant internal stresses and deformation so large beams run along the edges of such shells to stiffen them. The feet-shaped piers that support the cantilevered shells are packed with reinforcing rods to take up the tensile stresses generated by the 82-foot overhangs.
It is possible to build shells with much less material, as a Mexican architect Felix Candela demonstrated in a number of buildings in the 1950s and 1960s. A good example is his restaurant at Xochimilco, Mexico, 1958. The concrete is only about 4 inches (10.2 centimeters) thick. The rigidity of the structure is a function of its double curvature, for it is curved.
A shell may also be curved or folded in only one direction. A good example of this is an accordion-fold shell, as in the Minneapolis International Airport Terminal building, 1962-63 by Cerny Associates. A particularly interesting use of a folded shell is in the Assembly Hall at the University of Illinois Urbana, 1961-62, by Harrison and Abramovitz, with the engineers Ammann and Whitney. This dome consists of a folded plate, 394 feet (120 meters) in diameter, which rests on a series of radial supports reaching upward from a footing ring at the base. The enormous lateral forces are taken up by a belt of almost 622 miles (1,000 kilometers) of steel wire wound under tension around it.
|
|
|
Exercise 4. Translate the words:
arch, post, truss, dimension, structure, span (v., n.), cantilever (v., n.), roof, tube, dome, curve, rotate, form (v., n.), handle, steel, member, construct, triangular, reinforce, shell, rigidity, fold, base, stiffen, juncture, belt, double, edge, rest on, carry.
Exercise 5. Choose the right translation from A to B:
A: juncture, rotate, belt, rest on, edge, radial, double, design, curve, tube, enormous, curvature, shell, fold, employ, stiffen.
B: складка, вращаться, лента, проект, труба, край, опираться на, шов, радиальный, двойной, изгибать, применять, огромный, изгиб, оболочка, придавать жесткость.
Exercise 6. Are these meanings correct or incorrect? Correct the mistakes:
wire – проволока
edge – край
rest on – опираться на
design – дизайн
stiffen – армировать
belt – лента
arch – арка
employ – нанимать
fold – сгибать
double – двойной
roof – крыша
span – пролет
shell – раковина
Exercise 7. Translate the following word combinations:
post and lintel construction, footing ring, space frame, considerable distance, substantial three-dimensional truss, steel tube, easily handled steel member, shell form, triangular plan, reinforced concrete cantilevered shell, total covered space, significant internal stress, feet-shaped pier, reinforcing rod, tensile stress, double curvature, lateral force, steel wire.
Exercise 8. Translate the following words as nouns and verbs:
space, span, design, cantilever, form, concrete, stress, plan, fold, shape, support, function, use, reach, force, subject, place, mix.
Дата добавления: 2018-10-26; просмотров: 267; Мы поможем в написании вашей работы! |
Мы поможем в написании ваших работ!