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Read the text and say how tunneling methods have changed by now.

ANCIENT TUNNELS

It is probable that the first tunneling was done by prehistoric people seeking to enlarge their caves. All major ancient civilizations developed tunneling methods. In Babylonia, tunnels were used extensively for irrigation; and a brick-lined pedestrian passage some 3,000 feet (900 metres) long was built about 2180 to 2160 BC under the Euphrates River to connect the royal palace with the temple. Construction was accomplished by diverting the river during the dry season. The Egyptians developed techniques for cutting soft rocks with copper saws and hollow reed drills, both surrounded by an abrasive, a technique probably used first for quarrying stone blocks and later in excavating temple rooms inside rock cliffs. Abu Simbel Temple on the Nile, for instance, was built in sandstone about 1250 BC for Ramses II (in the 1960s it was cut apart and moved to higher ground for preservation before flooding from the Aswān High Dam). Even more elaborate temples were later excavated within solid rock in Ethiopia and India.

The Greeks and Romans both made extensive use of tunnels: to reclaim marshes by drainage and for water aqueducts, such as the 6th-century-BC Greek water tunnel on the isle of Samos driven some 3,400 feet through limestone with a cross section about 6 feet square. Perhaps the largest tunnel in ancient times was a 4,800-foot-long, 25-foot-wide, 30-foot-high road tunnel (the Pausilippo) between Naples and Pozzuoli, executed in 36 BC. By that time surveying methods (commonly by string line and plumb bobs) had been introduced, and tunnels were advanced from a succession of closely spaced shafts to provide ventilation. To save the need for a lining, most ancient tunnels were located in reasonably strong rock, which was broken off (spalled) by so-called fire quenching, a method involving heating the rock with fire and suddenly cooling it by dousing with water. Ventilation methods were primitive, often limited to waving a canvas at the mouth of the shaft, and most tunnels claimed the lives of hundreds or even thousands of the slaves used as workers. In AD 41 the Romans used some 30,000 men for 10 years to push a 6-kilometre tunnel to drain Lacus Fucinus. They worked from shafts 120 feet apart and up to 400 feet deep. Far more attention was paid to ventilation and safety measures when workers were freemen, as shown by archaeological diggings at Hallstatt, Austria, where salt-mine tunnels have been worked since 2500 BC.

Text 7

You were told to write one page for the textbook on tunnel building. Use the following information. Do not forget to add pictures and charts.

FROM THE MIDDLE AGES TO THE PRESENT

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Because the limited tunneling in the Middle Ages was principally for mining and military engineering, the next major advance was to meet Europe’s growing transportation needs in the 17th century. The first of many major canal tunnels was the Canal du Midi (also known as Languedoc) tunnel in France, built in 1666 – 81 by Pierre Riquet as part of the first canal linking the Atlantic and the Mediterranean. With a length of 515 feet and a cross section of 22 by 27 feet, it involved what was probably the first major use of explosives in public-works tunneling, gunpowder placed in holes drilled by handheld iron drills. A notable canal tunnel in England was the Bridgewater Canal Tunnel, built in 1761 by James Brindley to carry coal to Manchester from the Worsley mine. Many more canal tunnels were dug in Europe and North America in the 18th and early 19th centuries. Though the canals fell into disuse with the introduction of railroads about 1830, the new form of transport produced a huge increase in tunneling, which continued for nearly 100 years as railroads expanded over the world. Much pioneer railroad tunneling developed in England. A 3.5-mile tunnel (the Woodhead) of the Manchester-Sheffield Railroad (1839–45) was driven from five shafts up to 600 feet deep. In the United States, the first railroad tunnel was a 701-foot construction on the Allegheny Portage Railroad. Built in 1831–33, it was a combination of canal and railroad systems, carrying canal barges over a summit. Though plans for a transport link from Boston to the Hudson River had first called for a canal tunnel to pass under the Berkshire Mountains, by 1855, when the Hoosac Tunnel was started, railroads had already established their worth, and the plans were changed to a double-track railroad bore 24 by 22 feet and 4.5 miles long. Initial estimates contemplated completion in 3 years; 21 were actually required, partly because the rock proved too hard for either handdrilling or a primitive power saw. When the state of Massachusetts finally took over the project, it completed it in 1876 at five times the originally estimated cost. Despite frustrations, the Hoosac Tunnel contributed notable advances in tunneling, including one of the first uses of dynamite, the first use of electric firing of explosives, and the introduction of power drills, initially steam and later air, from which there ultimately developed a compressed-air industry.

Simultaneously, more spectacular railroad tunnels were being started through the Alps. The first of these, the Mont Cenis Tunnel (also known as Fréjus), required 14 years (1857–71) to complete its 8.5-mile length. Its engineer, Germain Sommeiller, introduced many pioneering techniques, including rail-mounted drill carriages, hydraulic ram air compressors, and construction camps for workers complete with dormitories, family housing, schools, hospitals, a recreation building, and repair shops. Sommeiller also designed an air drill that eventually made it possible to move the tunnel ahead at the rate of 15 feet per day and was used in several later European tunnels until replaced by more durable drills developed in the United States by Simon Ingersoll and others on the Hoosac Tunnel. As this long tunnel was driven from two headings sepa-

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rated by 7.5 miles of mountainous terrain, surveying techniques had to be refined. Ventilation became a major problem, which was solved by the use of forced air from water-powered fans and a horizontal diaphragm at mid-height, forming an exhaust duct at top of the tunnel. Mont Cenis was soon followed by other notable Alpinerailroad tunnels: the 9-mile St. Gotthard (1872–82), which introduced compressed-air locomotives and suffered major problems with water inflow, weak rock, and bankrupt contractors; the 12-mile Simplon (1898–1906); and the 9-mile Lötschberg (1906–11), on a northern continuation of the Simplon railroad line.

Nearly 7,000 feet below the mountain crest, Simplon encountered major problems from highly stressed rock flying off the walls in rock bursts; high pressure in weak schists and gypsum, requiring 10-foot-thick masonry lining to resist swelling tendencies in local areas; and from high-temperature water (130° F [54° C]), which was partly treated by spraying from cold springs. Driving Simplon as two parallel tunnels with frequent crosscut connections considerably aided ventilation and drainage.

Lötschberg was the site of a major disaster in 1908. When one heading was passing under the Kander River valley, a sudden inflow of water, gravel, and broken rock filled the tunnel for a length of 4,300 feet, burying the entire crew of 25 men. Though a geologic panel had predicted that the tunnel here would be in solid bedrock far below the bottom of the valley fill, subsequent investigation showed that bedrock lay at a depth of 940 feet, so that at 590 feet the tunnel tapped the Kander River, allowing it and soil of the valley fill to pour into the tunnel, creating a huge depression, or sink, at the surface. After this lesson in the need for improved geologic investigation, the tunnel was rerouted about one mile (1.6 kilometres) upstream, where it successfully crossed the Kander Valley in sound rock.

Most long-distance rock tunnels have encountered problems with water inflows. One of the most notorious was the first Japanese Tanna Tunnel, driven through the Takiji Peak in the 1920s. The engineers and crews had to cope with a long succession of extremely large inflows, the first of which killed 16 men and buried 17 others, who were rescued after seven days of tunneling through the debris. Three years later another major inflow drowned several workers. In the end, Japanese engineers hit on the expedient of digging a parallel drainage tunnel the entire length of the main tunnel. In addition, they resorted to com- pressed-air tunneling with shield and air lock, a technique almost unheard-of in mountain tunneling.

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PART II

Text 1 

Find the words you have read in the text below and translate the word combinations having these words. Use the words in the sentences of your own.

II. Work in pairs. Think of 2 or 3 questions using the words from Ex. I. Answer the questions of your partner.

III. Try to answer the questions, then read the text and check your ideas.

1.What does the word “bridge” mean?

2.What was the prototype of the first bridge?

3.What was the first bridge made of?

BRIDGES

One of the outstanding statesmen once said in his speech “There can be little doubt that in many ways the story of bridge building is the story of civilization. By it we can readily measure an important part of a people’s progress”. Great rivers are important means of communication for in many parts of the world they have been, and still are, the chief roads. But they are also barriers to communication, and people have always been concerned with finding ways to cross them.

For hundreds of years men have built bridges over fast-flowing rivers or deep and rocky canyons. Early man probably got the idea of a bridge from a tree

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fallen across a stream. From this at a later stage, a bridge on a very simple bracket or cantilever principle was evolved. Timber beams were embedded into the banks on each side of the river with their ends extending over the water. These made simple supports for a central beam reaching across from one bracket to the other. Bridges of this type are still used in Japan and India. A simple bridge on the suspension principle was made by early man by means of ropes, and is still used in countries such as Tibet. Two parallel ropes suspended from rocks or trees on each bank of the river, with a platform of woven mats laid across them, made a secure crossing. Further ropes as handrails were added. When the Spaniards reached South America, they found that the Incas of Peru used suspension bridges made of six strong cables, four of which supported a platform and two served as rails.

All these bridges made possible crossings only over narrow rivers. The type of temporary floating bridge, the pontoon bridge, has been used for military purposes; military engineers can construct a temporary bridge on this principle, able to carry all the heavy equipment of a modern army, in an extremely short time.

The idea of driving wooden piles into the bed of the river in order to support a platform was put into practice 3,500 years ago. This is the basis of the “trestle” or pile bridge, which makes it possible to build a wider crossing easier for the transport of animals and goods.

With the coming of the railway in the 19th century there was a great demand for bridges, and the railways had capital for building them. The first railway bridges were built of stone or brick. In many places long lines of viaducts were built to carry railways; for instance, there are miles of brick viaducts supporting railways to London.

The next important development in bridge-building was the use of iron and, later, steel. The first iron bridge crossed the river Severn in Great Britain.

The idea of drawbridge, a bridge hinged so that it can be lifted by chains from inside to prevent passage, is an old one. Some Leningrad bridges were built on this principle. A modern bridge probably demands greater skill from a designer and builder than any other civil engineering project. Many things should be taken into consideration, and these may vary widely according to local conditions. In deciding what type of bridge is most suitable the designer has to allow for the type and weight of the traffic, and width and depth of the gap to be bridged, the nature of the foundations and the method of erecting the bridge. The designer has to calculate carefully how various loads would be distributed and to decide which building materials are more suitable for carrying these loads.

IV. Give English equivalents to the following words and word combinations:

поток, связь, консольный мост, канат, поручни, свая, понтонный мост,

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поддерживать, мостостроение, вбивать, с целью, посредством, разводной мост.

V. Find 10 pairs of synonyms:

chief, fast, to evolve, secure, purpose, to construct, to put into practice, to hang, crossing, for example, to suspend, to build, for instance, to appear, to put into operation, safe, rapid, passage, main, aim

VI. What notion is explained by the following definition?

-a structure of wood, iron, concrete, etc, built to provide a way across a river, road, railway, etc.

-a thing that bears the weight of something or prevents it from falling.

-any of several boats or hollow metal structures joined together to support a temporary road over a river.

-long ago, a structure over a moat of a castle that can be pulled up to stop people crossing.

VII. Think of three words/word combinations from the text. Try to explain it using a pantomime and let the rest of the group guess it.

VIII. Find the best continuation to the following ideas.

The story of bridge-building is... .

Early man got the idea of a bridge from... .

The Incas of Peru used… .

Suspension bridges are still used... .

Floating bridges are able to carry... .

A modern bridge demands… .

Designing a modern bridge one should allow for… .

IX. Answer the questions.

1.Why have people always been concerned with finding ways to cross rivers?

2.What did early man get the idea of a bridge from?

3.What types of bridges were evolved by early man?

4.Bridges of what type are used for military purposes?

5.When and why did the demand for bridges increase?

6.What are the functions of viaducts?

7.What was the important stage in bridge-building?

8.What things should be taken into consideration while designing modern bridges?

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Home Exercises

I.Memorize the words from Ex. I page 12.

II. Translate from English into Russian. Discuss the translation in your group.

1.The wine is roping.

2.While speaking she dropped a brick.

3.Slaveholders chain slaves.

4.Chains lift the bridge.

5.Farmers lift potatoes.

6.This family farmed two children.

7.This equipment is up to date.

8.He dates girls very often.

III. Translate the sentences paying attention to the words: shall, should, will, would, to be, to have.

2.The load is distributed among all piles.

3.The builders are to erect the bridge in a year.

4.The chain was enough to reach the opposite bank.

5.You will have to take measures to prevent spring waters from penetrating the foundation.

6.I was told that a temporary bridge would be built across the river.

7.If the concrete were of a better quality, no cracks would appear.

8.Had the beams of that cross-section been used before, their defects could have been readily discovered.

9.You should increase the width of the bridge.

10.Our aim is to facilitate the work of the builders as much as possible. 11.Having widened and deepened the canal, they made it possible for use by ocean-going ships.

12.The road is being extended and widened, the surface layer – being replaced.

IV. Describe the following types of bridges:

a bracket bridge; a suspension bridge; a floating bridge; a drawbridge.

Text 2 

I. Listen and repeat:

expansion [Iks'pxnSn] растяжение

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Find the words you have read in the text below and translate the word combinations having these words. Use the words in the sentences of your own.

II. Work in pairs. Think of 2 or 3 questions using the words from Ex. I. Answer the questions of your partner.

III. First scan the text for about 10 minutes and answer the question:

Is there any difference between “artificial structures” and “constructional works”?

CONSTRUCTIONAL WORKS ON RAILWAYS AND MOTORWAYS

The history of civilization showed that roads were and still remain one of the most important means for the development of the world economy. The remote areas make considerable demands on the expansion of road construction.

Arterial railways and motorways have to overcome different natural obstacles such as fast-flowing rivers, mountain ranges, deep and rocky gorges as well as urban structures. Men have built constructional works to provide a passage through these natural or artificial obstacles. The term «constructional works» denotes a collective totality of the structures used instead of the permanent way or subgrade at the intersection with different obstacles. Constructional works are aimed to protect the permanent way against the adverse environment effects or natural calamities and disasters strucks. The term incorporates the following structures: bridges, viaducts, aqueducts, overbridges, trestle bridges, culverts, tunnels, galleries, and revetment walls. The function of these structures is quite different from that of the civil engineering structures. That is why the term does not include buildings, wells, garages, etc., though they are also man-made structures.

The word «artificial» cannot denote the constructional works, because this word is associated with the artificial building materials. But the term «construc-

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tional works» originated from the idea of the highest inventive, artistic skills, qualification and experience of the first railway engineers who were scientists, artists and builders simultaneously. They possessed profound knowledge in different fields required for the erection of constructional works.

Constructional works are considered to be the most complicated ones and involve heavy outlays. Their share ranges from 15 to 50 per cent of the total capital investment for the road construction. But as a rule the total length of the constructional works does not exceed 5 or 6 per cent of the road length.

The obstacle determines the type and definition of the constructional works. At present there are more than twenty types of constructional works, which can be divided into two main groups: the bridgeworks and the tunnelworks.

A bridge is erected at the intersection of the road with a river or other water obstacle. But if a barrier is a narrow stream or a temporary channel it is much cheaper to construct a culvert. Such constructional works as viaducts, overbridges and trestle works are often confused in an ordinary life. People have always been concerned with finding ways to cross the gorges, canyons and ravines to speed the passage of traffic and pedestrians. They build viaducts to solve this problem and improve communication. A one-level traffic junction and a heavy traffic flow call for an overbridge providing traffic interchanges on more than one level.

A trestle bridge is built in cities when a traffic flow is affected by the houses, parks, and industrial areas. As a rule, a trestle bridge is rather long.

The tunnel types of constructional works are divided into tunnels driven through the mountain ranges and galleries located on the mountain slopes. They protect roads from stone downfalls, snow slips, avalanches, drifting and wet landslides. Retaining walls, revetment walls and balconies can provide a high degree of road protection from disasters. They are less complicated construction works.

IV. Read the text word by word and complete the following words.

V. Make up word combinations as they are used in the text from the words given below.

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trestle downfall

VI. What do these attributes from the text refer to? Make up sentences of your own using word combinations with these words.

Arterial, constructional, engineering, artificial.

VII. Which of these words do you associate with constructional works?

VIII. Complete the following sentences by writing no more than three words for each answer:

1.Some constructional works such as … have high architectural merits demonstrating a balance between art and science.

2.Constructional works are subdivided into ... .

3.… of the permanent constructional works is about 80 – 100 years and for temporary ones – about 10 – 15 years.

4.Tunnel operation requires the most considerable cost due to the problems of … .

5.Even the simplest constructional works call for great financial consideration during their designing, construction and… .

IX. Answer the following questions:

1.What does the term «constructional works» mean?

2.What are the main possible obstacles, which railways and motorways have to overcome?

3.What groups can constructional works be divided into?

4.Why are viaducts, overbridges and trestle bridges often confused?

5.Is there any difference between retaining walls and galleries? Can they be confused? Give an example.

Home Exercises

I.Memorize the words from Ex. I page 15.

II. What is the English for:

искусственные сооружения мостового типа; водопропускная труба; облицовочная стенка; горный хребет; путепровод; автодорога; снежные заносы; овраг; временный водоток; транспортные развязки; стихийные бедствия

Make up a short story using these words in English (the more words the better).

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