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VI. Correct the given sentences.

Model: The Project has been completed for 42 months.

-Oh, no! The Project will be completed within 42 months!

1.The Project is being financed through a loan agreement. 2. The bridge carries 2 x 3 lane carriageway. 3. This suspension bridge has 750 m main span and two approach viaducts. 4. On the left bank of the river approach road connects the bridge to the left roundabout. 5. The Project serves both the urban traffic of Semipalatinsk City and to the transit domestic international traffics.

VII. Write an article describing the situation with the Irtysh River Bridge Construction Project.

Home Exercises

I.Read the following article and render it in English.

Метромост через Иртыш – главная стройплощадка Омска в последние 5 лет. Как и во многих городах, находящихся по обеим сторонам крупных рек, в Омске проблема связи старой центральной части города и относительно новой заречной стоит наиболее остро. Таким же типичным оказалось и решение этой проблемы: создание совмещенного авто- и метромоста.

Строительство метромоста началось в декабре 2000 года. Новый мост соединил улицу Фрунзе с улицей Конева. Длина двухуровневого моста – 650 метров. На его нижнем уровне расположен туннель метро, сверху проходит шестиполосная автомобильная магистраль с шириной проезжей части 34 метра.

15 сентября 2005 г., в десять часов утра, начались первые испытания омского метромоста имени 60-летия Победы. Проверка была рассчитана на целый день, прочность сооружения испытывали 28 грузовиков.

Генеральная схема развития омского метро предусматривает строительство трех линий метрополитена с пересадочным кольцом. Метромост позволит соединить центр Омска с левобережьем после ввода пускового участка первой линии метрополитена. По планам, это должно произойти в 2008 году. Четырем станциям первой линии омского метрополитена уже присвоены названия: "Библиотека им. А.С. Пушкина", "Кристалл", "Соборная" и "Заречная".

Примечание. По расчетам областного правительства, объемы перевозок первого пускового участка составят 190 тыс. человек в сутки, или 69 млн. человек в год. С вводом всей первой линии, включающей 11 станций, объемы пассажирских перевозок возрастут до 330 тыс. человек в сутки,

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или 140 млн. человек в год. На обслуживание пускового комплекса планируют задействовать 1200 человек.

Text 19 

I. Listen and repeat:

II. Have you seen the Volga River and its bridges? What are they? Read the following text and find the answers to the following questions:

1.How many levels is the new bridge intended to carry traffic on?

2.What is the length of the designed bridge?

3.Why is a clear height of the bridge not less than 16 m?

4.What does the riverbed consist of?

5.How many piles are there under each pier?

6.How were the construction works on the river piers performed?

NEW BRIDGE ACROSS THE VOLGA RIVER, RUSSIA

Kineshma and Zavolzhsk, two industrial cities in the Ivanovo region facing each other across the banks of the Volga River, have had no direct transportation connection. The existing ferry crossing could not accommodate the growing road traffic, whereas railway transit between the two cities is inefficient because

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of considerable detour lengths.

The bridge project over the Volga presently under construction will provide a link for the railway lines and highways between the two cities, as well as for the neighbouring Central European territories of Russia to the northeast. The crossing route was planned away from Kineshma’s and Zavolzhsk’s centres, bearing in mind their future development and the requirements of the combined transport use (i.e., water, railway and road) on a regional scale. The new bridge is intended to carry traffic on two levels, the railway on the lower level and the highway on the upper. The superstructure is designed as a continuous steel lattice girder with two traffic levels. The railway superstructures on the left bank are single-span steel deck trusses; the highway superstructures on both banks are composite continuous deck plate girders. The dual carriageway is 9.5 m wide, with two 1.5 m wide sidewalks.

The crossing includes the main bridge across the Volga and five viaducts, (of which one is to carry a railway, the other four accommodating highway traffic). A new railway line will pass under the viaducts.

The entire length of the crossing is 15.9 km, the bridge over the Volga being about 1900 m long. The civil works are to be carried out in two stages. First, railway traffic will open and during the second stage the construction will be completed for road traffic.

The height of the bridge and the length of the spans in the riverbed part were chosen based on the dimensions and the structure of the deck and to comply with the current regulations on bridge clearances. These regulations call for a clear height of not less than 16 m, and a navigable span length in the clear passage of not less than 140 m. The elevation of both rail and road levels has been adjusted accounting for the depth of the approach cuts, bearing in mind the provision that their lower edges must remain above groundwater table. The difference between the road and rail levels is 17.05 m.

The terrain of the crossing is of complex geology. The riverbed consists of silts and sands with varying grain size, prone to flood erosion. Further down, there are gravel layers containing sand, then loams and sands, with hard clays underlying all. The foundations of the bridge piers in the 1100 m wide riverbed zone bear upon vertically driven cast-in-place piles, 1.5 m in diameter; the land piers are mainly supported by driven precast concrete piles of 0.6 m diameter. The piers were designed to withstand the ice loads of blocks up to 0.9 m thick and up to 300 x 400 m in size.

The abutments of the bridge are of cast-in-place concrete bearing on 0.6 m diameter tubular piles driven to a depth of up to 18 m below the river bottom. The number of piles under each pier is from 48 to 56. Some of the piles are driven vertically; others are driven in a batter of 4:1 to 10:1. Some of the pier foundations include prism-shaped concrete piles!

All the construction works on the river piers were performed afloat using

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floating jib cranes and scows to transport structural elements and materials. During the winter, the ice cover was broken in order to ensure navigation for these vessels. Prior to piling works, steel casings were sunk to the required depth. Then, bore holes were drilled inside the casings reaching 29-32 m deep from the bottom level of the piling cap, reinforcement cages lowered and concrete mix poured.

The stability of the superstructure in erection was ensured by securing it to the protruding longitudinal girders of the spans already erected, application of temporary connector devices in truss chords and by other means in accordance with the erection procedure charts. The members to be erected were supplied via a temporary rail track laid on the railway deck. To lay the concrete decking slabs, special erection rigs were used.

III. From the words below make up word combinations as they were used in the text.

Ferry, railway, lines, crossing, tubular, table, erection, rigs, piles, structural, clear, passage, elements, groundwater.

IV. Match the given words with their common and special meaning (consult the dictionary). In what meaning are these words used in the text?

V. Are these statements true or false?

1.The bridge over the Volga will provide a link for the highways and railway lines.

2.The new bridge is intended to carry traffic on four levels.

3.The highway is designed to be on the lower level and the railway on the upper.

4.The dual carriageway is 9.5 m wide, with a 1.5 m wide sidewalk.

5.The entire length of the bridge over the Volga is 15.9 km.

6.A clear height of the bridge is not over than 16 m.

7.The riverbed consists of loams, sands and hard clays.

8.Some of the piles are driven horizontally.

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9. The protruding longitudinal girders of the spans, temporary connector devices in truss chords ensure the stability of the superstructure.

VI. Copy and complete the table.

Home Exercises

I.Memorize the words from Ex. I page 79.

II. Make a drawing of the bridge in question, put dimensions and describe the bridge.

Text 20 

I. Listen and repeat:

II. Read the following text and write out the key words.

SOUTH BRIDGE OVER THE DNEPR RIVER IN KIEV

The new South Bridge over the Dnepr River in Kiev, Ukraine, consists of a 564.5 m long cable-stayed portion with a main span of 271 m, and a concrete approach viaduct with a total length of 662 m. The bridge carries a six-lane roadway, two rail tracks and four large-diameter water pipes.

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Stiffening girders on the main span side of the pylon are continuous threespan steel box girders, while on the opposite side the girders are segmental prestressed concrete box sections. The three-span continuous box girders are made of low-alloy steel with a minimum yield strength of 390 MPa. The shopfabricated components were welded. Field splices were either welded or joined by high-strength bolts. Bolting was used where automatic welding was impractical because of the short length of the weld or because of difficult access.

The steel girders were preassembled on the shore and erected by launching. The girders were equipped with a launching nose and stiffened with a temporary strut system.

Because of the considerable width of the bridge, 42 m, the bearings at the piers permit lateral displacement of the superstructure. At the pylon, hinged conditions are provided by supports with limited rotational capability in the vertical and the horizontal planes.

In order to provide the necessary counterweight mass, concrete rather than steel was needed for the two-span anchorage girder. The anchor spans consist of modified K-type concrete box segments used in the approach spans. Exterior cross section dimensions were retained; but thicknesses were increased and new duct openings for the lateral and vertical prestressing were provided, as were ledges for anchorage of added prestressing strands.

The stay cables are anchored in the cast-in-place concrete of the longitudinal splices between precast box sections. Anchorage concrete is pre-stressed transversely by strands joining the walls of adjacent precast sections and longitudinally by 36 cables, each with a prestressing force of 2950 kN. The vertical and the transverse tensioning cables through the anchorage zones effectively join the precast and the cast-in-place portions of the cross section into a monolithic structural entity. At the end support of the anchor spans, tie down to the pier is accomplished by means of 16 vertical anchor cables of the same size as the cable stays.

The pylon is a two-legged cast-in-place concrete frame with two precast concrete cross struts. Its legs are located in the space between the roadway and the rail tracks. Cost comparison between steel and concrete pylons showed that the former would be about four times more expensive. Aside from reasons of economy, concrete was judged to lend itself better to architectural treatment.

Several solutions for the pylon-girder junction were studied. Eccentric hinged connections between the bottom flanges of the stiffening girders and the pylon were chosen. This scheme best solves the problem of joining the steel and the concrete superstructures, and considerably reduces the bending moments in the girders.

The aerodynamic stability of the bridge and its principal elements was investigated by calculations and wind tunnel testing. Stress distribution in connections was verified on models.

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I. Memorize the words from Ex. I page 83.

II. Paraphrase the sentences using the Passive Voice.

1.High-strength bolts fixed field splices.

2.They preassembled the steel girders on the shore.

3.A temporary strut system stiffened the girders.

4.They used modified K-type concrete box segments in the approach spans.

5.The location of pylon legs is between the roadway and the rail tracks.

III. Tell everything you know about the new South Bridge over the Dnepr River in Kiev using your key words.

Text 21 

II. Why is it necessary to strengthen bridges? Is it done often or seldom? Why? Read the text and say why the road bridge over the river Dvina in Vitebsk was strengthened.

STRENGTHENING A ROAD BRIDGE OVER THE RIVER DVINA

Some details of reconstruction of the road bridge over the river Dvina in Vitebsk are given in the November 1970 issue of “Transportnoye Stroitelstvo”. The bridge was erected in 1934. It crosses the main stream of the river in two continuous spans (2 x 63 m) comprising four steel trusses carrying a reinforced concrete deck. During the last war the bridge was partly destroyed and when reconstructed its carrying capacity was limited to 2.5 t. The bridge had to be strengthened.

First proposal for the reconstruction called for a new reinforced concrete deck and for the prestressing of the reinforced steel trusses. The proposed method was rather laborious and a new, cheaper, speedier and more elegant schemes for strengthening the river spans was put forward and found acceptable. The design called for the composite action of the existing concrete deck with steel trusses and for the reduction in dead weight.

The execution was simple. First the wearing surface was removed from the

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deck. Holes were cut next in the concrete deck over panel points in trusses where steel shear connectors were riveted to the top boom to ensure interaction between the truss and the concrete deck.

The next operation was to place eight 200 t hydraulic jacks under each main truss over the central pier and to lift the superstructure 20 cm. To avoid cracking of the concrete, transverse grooves were cut in the deck slab prior to lifting. The raising of the structure resulted in the reversal of stresses in the trusses. The trusses were then reinforced according to the design requirements and in situ concrete was poured into the holes in the deck to bind it with the steel truss. Expanding cement was used in the concrete mix.

When the concrete had reached its designed strength the superstructure was lowered and the jacks removed. Calculations showed that about 50% of the working stresses in some truss components were due to the dead load only. To reduce the loading lightweight concrete was used for wearing surface and further reductions in weight were achieved by using asbestos cement pipes for hollow type deck construction.

III. Match the English and the Russian equivalents. Make up sentences with the English words and let your partner translate them.

IV. Fill in the appropriate word from the list below: consists, reduce, between, necessary, filled, avoid

1.The road bridge over the river Dvina in Vitebsk … of two continuous spans.

2.Reconstruction was … to strengthen the structure.

3.Steel shear connectors were used for interaction … the truss and the concrete deck.

4.Transverse grooves were cut in the deck slab to … cracking of the concrete.

5.The holes were … by concrete to bind the deck with the steel truss.

6.To … the loading lightweight concrete was used.

V. Analyse the text and determine the main and additional information of each paragraph.

VI. Retell the text. Use the answers to the following questions:

1. Why had the road bridge over the river Dvina to be strengthened?

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2.What can you say about the first proposals for the reconstruction?

3.What advantages did a new scheme for strengthening the river spans have?

4.What was the first stage of the reconstruction work?

5.What was done during the next operation?

6.When was the superstructure lowered and the jacks removed?

7.What did calculations show?

8.How was the reduction of the loading achieved?

Home Exercises

I.Memorize the words from Ex. I page 86.

II.Use this model for compression:

Model: the tubes made of steel – steel tubes

The deck made of reinforced concrete; the method which was proposed; the trusses made of reinforced steel; the spans over the river; the bridge that was partly destroyed.

Text 22 

I. Scan the text for 10 minutes and choose the answer which you think fits best according to the text. Then read the text carefully and check your ideas.

1. The elegant century old suspension bridge is …

a) the Blackfriars Bridge b) the Hampton Court Bridge c) the Hammersmith Bridge

2. The earliest bridge in Great Britain is …

a) the Old London Bridge b) the Tower Bridge c) the Albert Bridge

3.The Old London Bridge was of great danger for ...

a) pedestrians b) automobiles c) boats

4.The «Lockwood» is a …

a) chapel b) viaduct c) ferry 5. Over the Thames there are …

a) 26 bridges b) 16 bridges c) 23 bridges 6. The «Britannia» bridge was made of … a) cast iron b) stone c) steel

BRIDGES OF GREAT BRITAIN

There are twenty-six bridges spanning the Thames. The most famous among

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