Учебники 80271

4. Прочитайте текст и сравните информацию о балочных и консольных мостах. В чем их отличие?

TEXT: BEAM AND CANTILEVER BRIDGES

Beam bridges

The construction of a beam bridge is the simplest of all the types of bridges. Beam bridges are horizontal beams supported at each end by piers. The earliest

beam bridges were simple logs that sat across streams and similar simple structures. In modern times, beam bridges are large box steel girder bridges. They are made up mostly of wood or metal. Beam bridges typically do not exceed 250 feet long. The longer the bridge, the weaker. The world's longest beam bridge is in southern Louisiana, U.S.A., at 38.35 km, with individual spans of 17 m.

A beam bridge carrying a railway line over a road in Dorset,

England.

Cantilever bridges

Cantilever bridges are built using cantilevers—horizontal beams that are supported on only one end. Most cantilever bridges use two cantilever arms extending from opposite sides of the obstacle to be crossed, meeting at the center. The largest cantilever bridge is the 549-metre Quebec Bridge.

In a cantilever bridge, each section of the bridge deck is balanced across the piers by the sections on either side of it. Loads are carried vertically to the piers and abutments and evened out by a rigid framework of metal trusses (criss-cross beams).

Examples of cantilever bridges include the Queensboro Bridge in New York City, the Crescent City Connection in New Orleans, and the Forth Bridge in Scotland.

Long cantilevered bridge on the Mississippi River near

New Orleans.

5. Обратите внимание на пассивные конструкции во времени Simple.

Образец: The first bridges were made by nature itself.

A bridge is built to span a valley, a road or body of water.

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Для образования Passive Simple необходим вспомогательный глагол ‘to be’ в соответствующей форме и времени, а также Participle II (3 форма основного глагола).

Согласно приведенному выше образцу найдите в прочитанном тексте случаи пассивных конструкций.

6. Прочитайте следующую информацию и скажите, для какого типа мостов (балочных или консольных – beam or cantiliver) она верна:

1. These bridges are horizontal beams supported at each end by piers. 2. These bridges are horizontal beams that are supported on only one end. 3. This type of bridges typically does not exceed 250 feet long. 4. These bridges are large box steel girder bridges. 5. They use two arms extending from opposite sides and meeting at the centre. 6. Loads are carried vertically to the piers and evened out by a rigid framework. 7. The earliest bridges of this type were simple logs that sat across streams.

7. Задайте собеседнику следующие вопросы и выслушайте, что он думает по этому поводу:

1.How do you think if the construction of a beam bridge is complex?

2.Do you know when the earliest beam bridges were constructed?

3.What material are they made up mostly?

4.How long are they typically?

5.What is the dependence between length and strength of the beam bridge?

6.How do cantilever bridges differ from beam bridges in their construction?

7.How are loads carried in cantilever bridges?

8.Can you give the examples of cantilever bridges?

8. Что бы вы рассказали о двух типах мостовых конструкций (балочных и консольных), готовясь к презентации? В своем рассказе используйте сле-

дующие фразы: I’d like to tell you about... , the main difference ... , it should be noted that ... , the example of ... is ... , it is known that ... .

LESSON 4. ARCH AND SUSPENSION BRIDGES

1. Какие английские соответствия приведенным ниже русским словам можно найти в тексте?

Компрессия, горизонтально, вертикально (вертикальный), структура, бамбук.

2.Запомните слова, необходимые для понимания текста:

3. Найдите соответствия английских и русских фраз:

abutments at each end pushes its load out pack together tightly separate stone arches

attached to caissons or cofferdams implanted deep into

reinforced with girders and trusses stretch out to the abutments

береговые опоры на каждом конце выталкивает свою нагрузку уплотняется отдельные каменные арки

прикрепленные к кессонам или перемычкам внедренные глубоко в усиленные балками и связками

растягиваются к береговым опорам

4. Прочитайте и переведите текст на русский язык. Скажите в чем отличие арочных мостов от подвесных?

TEXT: ARCH AND SUSPENSION BRIDGES

Arch bridges

Arch bridges are arch-shaped and have abutments at each end. The earliest known arch bridges were built by the Greeks and include the Arkadiko Bridge.

The arch is in compression and pushes its load out horizontally and vertically into the supporting ground. A load makes it stronger: an arch made of bricks or stones will pack together tightly when a load is placed on it, making a more solid structure. Arch bridges can be constructed over a falsework, or temporary scaffolding.This method is usually employed with reinforced concrete arch bridges. With steel arches, however, a technique has been developed whereby the finished sections are held in place by wires that supply a cantilever support . Cranes move

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along the top of the arch to place new sections of steel while the tension in the cables increases.

Examples of arch bridges include the Mostar Bridge in Bosnia Herzegovina and the Charles Bridge in Prague.

Stone arch bridge in Yemen

The Palladian stone arch bridge, Bath, England. You can see that the lower part of the bridge is made up of five separate stone arches

Sydney Harbor Bridge during the 2000 Olympics

Suspension bridges

Suspension bridges are suspended from cables. The earliest suspension bridges were made of ropes or vines covered with pieces of bamboo. In modern bridges, the cables hang from towers that are attached to caissons or cofferdams. The caissons or cofferdams are implanted deep into the floor of a lake or river. The longest suspension bridge in the world is the 3,909 m in Japan.

The bridge deck is reinforced with girders and trusses underneath. It hangs from many, relatively thin, vertical suspender cables supported by the longer, thicker main cables that stretch between the vertical piers. With suspension bridges, the foundations and the towers are built first .Then the cable is fastened-up to the tower and across to the opposite tower and anchorage. Construction begins on the deck when the cables are in place, with work progressing toward the middle from each end of the structure.

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At each end of the bridge, side cables stretch out to the abutments (where the bridge is built into the ground). All the cables are in tension.

Famous suspension bridges include the Humber Bridge and the Clifton Suspension Bridge in England, the Golden Gate Bridge in California, and the Brooklyn Bridge in Manhattan.

The Tamar Bridge, completed in 1961, spans the River

Tamar, England

5. Заполните пропуски в предложениях, выбрав правильный вариант перевода.

A load makes the arch bridge stronger.

Нагрузка делает арочный мост ... .

а) прочнее; б) слабее.

The arch pushes its load out horizontally and vertically.

Арка выталкивает свою нагрузку ... направлении. а) в горизонтальном и вертикальном; б) в вертикальном направлении.

The cables in suspension bridges are attached to caissons or cofferdams.

В подвесных мостах тросы прикреплены ... .

а) к кессонам; б) к береговым опорам.

The bridge deck is reinforced with girders underneath.

Опалубка моста усилена внизу ... .

а) тросами; б) балками.

6. Заполните пропуски в предложениях, используя приведенные ниже слова.

1.Arch bridges are arch-shaped and have ... at each end.

2.An arch made of bricks or stones will ... tightly when a load is placed on it.

3.Suspension bridges are suspended from ... .

4.The caissons are ... deep into the floor of a lake or river.

5.At each end of the bridge side cables ... to the abutments.

6.The arch is in compression and ... its load out horizontally and vertically.

Abutments, pushes, cables, stretch out, pack together, implanted.

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7. Соедините разрозненные части предложений.

1.The earliest known arch bridges were built by...

2.Suspension bridges are suspended from ...

3.The earliest suspension bridges were made of ropes or vines covered ...

4.The longest suspension bridge in the world is the 3,909 m ...

5.The bridge deck hangs from relatively thin, vertical suspender cables supported...

6.All the cables are ...

7.Famous suspension bridges include ...

a)... the Golden Gate Bridge in California and the Brooklyn Bridge in Manhattan. b)... the Greeks.

c)... in tension. d)... cables.

e)... by the longer, thicker main cables. f)... with pieces of bamboo.

g)... in Japan.

8. Переведите на английский язык следующие предложения, обращая особое внимание на выделенные термины:

1.Арочные мосты - дугообразные конструкции, имеющие береговые опоры на концах.

2.Арка находится в сжатом состоянии и выталкивает свою нагрузку в вертикальном и горизонтальном направлении на поддерживающий грунт.

3.Нагрузка делает арку прочнее.

4.Подвесные мосты свешиваются на тросах.

5.В современных мостах тросы свешиваются с пилонов и прикрепляются к кессонам.

6.Кессоны глубоко внедряются в дно озера или реки.

7.Опалубка моста снизу укрепляется балками.

8.Все кабели находятся в натянутом состоянии.

9.К известным подвесным мостам относятся мост Золотые Ворота и Бруклинский мост.

LESSON 5. CABLE-STAYED AND TRUSS BRIDGES

1. Найдите английские эквиваленты следующим русским словам:

2. Обратите внимание на следующие слова и запомните их:

3. Выразите желание услышать подтверждение по поводу сказанного, преобразовав данные предложения в разделительные вопросы (tagquestions).

Образец: Сable-stayed bridges are held up by cables, aren’t they?

1.The first known cable-stayed bridge was designed in 1784 by Loescher. 2. The longest cable-stayed bridge is the Sutong Bridge in China. 3. A cable-stayed bridge looks much like a suspension bridge. 4. The deck of a suspension bridge is supported indirectly from the main cables. 5. A fan of diagonal cables supports the deck directly from the piers. 6. A cable-stayed bridge can be supported from a single pier in the middle. 7. Truss bridges have a solid deck and gusset-joined girders for the sides. 8. Early truss bridges were made of wood. 9. This type of bridge is often used to carry railroad lines over rivers or roads. 10. It takes the form of a hollow box with a solid floor.

4. Прочитайте текст и дайте ответ на вопрос, поставленный в тексте.

TEXT: CABLE-STAYED AND TRUSS BRIDGES

Cable-stayed bridges

Like suspension bridges, cable-stayed bridges are held up by cables. However, in a cable-stayed bridge, less cable is required and the towers holding the cables are proportionately shorter. The first known cable-stayed bridge was designed in 1784 by Loescher. The longest cable-stayed bridge is the Sutong Bridge in China.

At first glance, a cable-stayed bridge looks much like a suspension bridge, so what's the difference? The deck of a suspension bridge is supported indirectly from the main cables via suspender cables that hang vertically downward. In a cablestayed bridge, a fan of diagonal cables supports the deck directly from the piers. A cable-stayed bridge reduces the bending in the mid-section of the deck and, unlike a suspension bridge, can be supported from a single pier in the middle. However, it usually requires a stronger and bulkier deck than a suspension bridge.

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Examples of cable-stayed bridges include the Vasco da Gama Bridge in Portugal, the Millau Viaduct in France, the Hangzou Bridge in China, and the Chords Bridge in Jerusalem.

Cable-stayed bridge in Charleston S.C.

Truss bridges

Truss bridges are composed of connected elements. They have a solid deck and gusset-joined girders for the sides. Early truss bridges were made of wood, and later of wood with iron tensile rods, but modern truss bridges are made completely of metals such as wrought iron and steel or sometimes of reinforced concrete.

This type of bridge is strong, light, and relatively cheap to construct and is often used to carry railroad lines over rivers or roads. Typically, it takes the form of a hollow box (open at the top) with a solid floor and either open or closed sides reinforced with diagonal trusses. Like a beam bridge, the top is in compression and the floor in tension. While the vertical members are in compression, the diagonal trusses are in tension. With some truss bridges, the span is floated into position after the piers have been erected and then raised into place by means of jacks or cranes.

A truss bridge carrying a pedestrian walkway over a railroad line in Dorset, England

Continuous under-deck truss bridge

Over-deck truss bridge with steel girders and wooden carriageway

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5. Выпишите из текста слова, образованные суффиксальным способом и

6. а) Подтвердите или б) опровергните следующие утверждения, начав свое высказывание соответствующей фразой:

а) I think, you’re right; certainly; I agree with you.

б) I’m afraid, I don’t agree; I don’t think so; I disagree; I think you’re mistaken.

1. In a cable-stayed bridge less cable is required than in a suspension bridge. 2. A cable-stayed bridge reduces the bending in the mid-section of the deck. 3. Truss bridges are composed of single elements. 4. Modern truss bridges are made completely of concrete. 5. Truss bridges are strong, light but expensive to construct.

6.The vertical members of a truss bridge are in compression, the diagonal trusses are in tension.

7.Ответьте по-английски на следующие вопросы:

1. How are cable-stayed bridges held up? 2. When was the first known cable-stayed bridge designed? 3. How does a cable-stayed bridge look like? 4. What is the deck of a suspension bridge supported via? 5. Does a cable-stayed bridge reduce or increase the bending in the mid-section of the deck? 6. What are the examples of cable-stayed bridges? 7. What elements are truss bridges composed of? 8. What are modern truss bridges made of? 9. What is this type of bridges used for? 10. What is its similarity with a beam bridge?

8. Выберите из текста ключевые фразы и, используя их, расскажите о вантовом и балочном мостах.

LESSON 6. MORE INFORMATION ABOUT BRIDGES

1. Прочитайте интернациональные слова и догадайтесь об их значении.

Transport, aqueduct, viaduct, image, type, style, pontoon, improvise, military, vertically, limit, automobile, special, restaurant, antenna, line, fixed, ideally, electrically.

2. Запомните следующие слова, необходимые для правильного понимания текста: