TIẾNG ANH CHUYÊN NGÀNH XÂY DỰNG CẦU ĐƯỜNG

Giáo trình tiếng anh chuyên ngành xây dựng cầu đường bổ sung các kĩ năng ngoại ngữ chuyên ngành cho các kĩ sư cầu đường . Trong thời kia hội nhập ngoại ngữ là vấn đề không thể thiếu đối với các kĩ sự. Đặc biệt là đối với nghề kĩ sư xây dựng

Unit 1 FOR ROADS AND BRIDGES PLANNING AND DESIGN

1 READING

The Highway Classification System

a What do you think when you see a new road? Complete the diagram below.

Now, compare your diagram with your partners.

b In groups, discuss the different types of classifying highways

How many categories are there?

What are the purposes of the highway classifications?

c Read the first paragraph of Highway Classifications and complete the following table.

Speed

Width Safety

Landscape

THE ROAD THE ROAD

Highway Classification Purpose Examples

By design types - is used for highway location

and design procedures

- freeways, conventional streets, and highways

of service they provide, was developed for transportation planning purposes.Comprehensive transportation planning, an integral part of total economicand social development, uses functional classification as an importantplanning tool

Functional classification is the process by which streets and highways aregrouped into classes according to the character of traffic service that theyare intended to provide There are three highway functional classifications:arterial, collector, and local roads All streets and highways are grouped intoone of these classes, depending on the character of the traffic (i.e., local orlong distance) and the degree of land access that they allow Theseclassifications are described in Table 1

Table 1 Functional Classification Systems

Functional

System

Services Provided

Arterial provides the highest level of service at the greatest speed

for the longest uninterrupted distance, with some degree

of access control

Collector provides a less highly developed level of service at a lower

speed for shorter distances by collecting traffic from localroads and connecting them with arterials

Local consists of all roads not defined as arterials or collectors;

primarily provides access to land with little or no throughmovement

Typically, travellers will use a combination of arterial, collector, and localroads for their trips Each type of road has a specific purpose or function.Some provide land access; others provide travel mobility at varying levels

There is a basic relationship between traffic mobility and land access, asillustrated in Figure 1

Figure 1 Relationship of functionally classified highway systems in serving

traffic mobility and land access.

Once the functional classification of a particular roadway has beenestablished, the allowable range of design speed, the principal limitingdesign parameters, and horizontal and vertical alignment have also defined.Similarly, functional classification establishes the basic roadway cross section

in terms of lane width, shoulder width, type and width of median area, andother major design features (see Figure 2)

Land Access

Mobility

Figure 2 The flexibility available to a highway designer is considerablylimited once a particular functional classification as been established.

The importance of the functional classification process as it relates tohighway design lies in the fact that functional classification decisions aremade well before an individual project is selected to move into the designphase Moreover, such decisions are made on a systemwide basis by city orcounty as part of their continuing long-range transportation planningfunctions Thus, the functional classification of a particular section ofhighway may well represent a decision made 10 or more years ago

d Match the terms to the definitions

Accessibility  a provide a balance between mobility and land access.Mobility  b refers to the ease of reaching destinations

Design speed  c provide a high level of mobility for through

movement with low level of accessibility

Arterial roads  d provide a high level of access to adjacent properties

but a low level of mobility

Collector roads  e is the ability to move or travel around easily

Local roads  f is a selected speed used to determine the various

geometric features of the roadway

Arterial road Collector road Local road

e Fill in the blank with suitable words

1 All streets and highways are grouped into one of these classes, depending on the

character of the traffic and the degree of that they allow

2 Travellers will use a of arterial, collector, and local roads for theirtrips

3 Collector roadways provide a balance between and land access

4 provides the highest level of service at the greatest speed for the

longest uninterrupted distance

5 A determination of functional classification establishes the basic

roadway

6 Functional classification decisions are made as part of their continuing range functions

long-f Decide whether the following statements are True (T) or False (F)

1. Arterial, collector and local are grouped into highway functional

classifications

2 Traffic mobility and land access don’t have any relationship

3 Local roads provide a high level of access to adjacent properties

but a low level of mobility

4. Without defining the allowance range of design speed, horizontal

and vertical alignment can’t be defined

5 The functional classification of a particular section of highway

may well represent a decision made 10 or more years ago

3 SPEAKING

In pairs, describe the figure 1 Relationship of functionally classified highway systems

in serving traffic mobility and land access using comparison of adjectives.

Arterials provide higher mobility than collectors and locals

4 READING AND WRITING

a Complete the table with the appropriate descriptions of Functional

Classification.

A Highways generally providing direct service between cities and important

economic, political, cultural centres; Partial Controlled Access Highways; ≥4

lanes

B. Local Roads providing direct service between districts, cooperatives, etc

C Super high class Highway for high speed traffic with controlled access and

quick travel time, providing transport service between large important cities

D Highways providing direct service between several towns and local economic,

political, cultural centres Roads connecting them to the arterial network and

Technical Classification Administrati

ve Classificatio n Level Rollin

g Mountainou s

100 80

80 60

b Translate the above table into Vietnamese.

Grammar focus: Zero relative clause (Omitting relative pronouns)

E.g Arterials are the highways providing the highest mobility.

(understood: Arterials are the highways which provide the highest mobility)

HIGHWAY CROSS-SECTION ELEMENTS

1 VOCABULARY BUILDING

a Guess the meaning of the following terms.

b Label the following cross-section elements.

MEDIAN Right-of-Way

Toe of Slope Fill Slope

(Embankment)

Base Course Surface Course

Information sign Sound/Noise barrier Flexible railing Median Curb Railing/Wall barrier Shoulder (Outer) Roadway Shoulder (Inner) Traveledway Pavement

2 LISTENING

a What is a safe highway? How can we design a safe highway?

b Watch a video and choose the best answer (A, B, C, or D) for the following sentences.

1 will be a new arterial highway for Japan

A Expressway B New Tomei C This expressway

D New Tomei Expressway

2 We aim to make this the world’s safest, most pleasant expressway co-existingharmoniously with

A environment B natural C nature D feature

3 We are engaged in a wide range of measures to accidents on expressways

A maximize B optimize C customize D minimize

4 We have widened the road, reduced and so decreased driver stress andimproved road visibility

A curves and bends B curves and slopes C slopes D curves

5 We have made traffic signs and much easier to read by improving the colors andshapes based on intensive testing

A signboards B signboard C side roads D side road

6 The expressway is paved with paving material

A traditional B modern C advanced D conventional

7 The expressway has been planned and designed anticipating a possible

A tsunami B typhoon C earthwork D earthquake

8 In addition to being light and pleasant to drive through, we have employed lighting consuming less power than conventional lights

A eco-friendly B ecosystem C economic D environment-friendly

9 We use advanced systems with TV cameras to monitor the entire expressway

A supervising B monitoring C inspecting D observing

c Watch again for more information What have they done to make New Tomei Expressway the world’s safest, most pleasant expressway?

3 SPEAKING

HORIZONTAL AND VERTICAL ALIGNMENT

Horizontal and vertical alignments are permanent elements that should not be designed independently They complement each other, and poorly designed combinations can spoil the good points and aggravate the deficiencies of each Working drawings, with the profile plotted jointly with the plan, assist in analyzing the horizontal alignment and profile relationship in roadway design.

Indicate in the following figures whether the layout is a good or poor highway

design practice by checking the appropriate box

Useful expressions:

 Good design practice  Poor design practice  Good design practice  Poor design practice

 Good design practice  Poor design practice  Good design practice  Poor design practice

I think so

I don’t think I’m sure

Probably As you can see

Because

 Good design practice  Poor design practice  Good design practice  Poor design practice

 Good design practice  Poor design practice  Good design practice  Poor design practice

 Good design practice  Poor design practice  Good design practice  Poor design practice

 Good design practice  Poor design practice  Good design practice  Poor design practice

 Good design practice  Poor design practice  Good design practice  Poor design practice

Unit 1 PLANNING AND DESIGN FOR ROADS AND BRIDGES

1 WARM-UP

a Match the names of the bridge (1-4) to the

pictures (A-D)

1 Tower Bridge of London, England

2 Golden Gate Bridge, San Francisco, America

3 Sydney Harbor Bridge, Australia

4 Akashi-Kaikyo Bridge, Japan

b What do you know about these bridges?

A

B

C

D

2 VOCABULARY BUILDING

Types of Bridges

Look at the following pictures, which bridges do you know are of these kinds?

1 Beam Bridge

Basic Beam Bridge Actual Beam Bridge

A beam or "girder" bridge is the simplest and most inexpensive kind of bridge In its mostbasic form, a beam bridge consists of a horizontal beam that is supported at each end bypiers The weight of the beam pushes straight down on the piers

2 Arch Bridge

Basic Arch Bridge Actual Arch Bridge

Arch bridges are one of the oldest types of bridges and have great natural strength.Instead of pushing straight down, the weight of an arch bridge is carried outward alongthe curve of the arch to the supports at each end These supports, called the abutments,carry the load and keep the ends of the bridge from spreading out

3 Suspension Bridge

Basic Suspension Bridge Actual Suspension Bridge

Aesthetic, light, and strong, suspension bridges can span distances from 2,000 to 7,000feet - far longer than any other kind of bridge They also tend to be the most expensive tobuild

4 Cable-stayed Bridge

Basic Cable-stayed Bridge Actual Suspension Bridge

Cable-stayed bridges may look similar to suspensions bridges both have roadways thathang from cables and both have towers The difference lies in how the cables areconnected to the towers In suspension bridges, the cables ride freely across the towers,transmitting the load to the anchorages at either end In cable-stayed bridges, the cablesare attached to the towers, which alone bear the load

Basic Truss Bridge Actual Truss Bridge

A truss bridge is a bridge that has a load bearing structure supported by trusses Trussesare triangle shaped units, connected at joints Truss bridges are among the oldest inmodern bridges

3 READING

DESIGN OF HIGHWAY

BRIDGES

A highway bridge is a structure that

crosses over a body of water, traffic, or

other obstruction, permitting the smooth

and safe passage of vehicles In highway

transportation systems, the term “bridge”

is usually reserved for structures over

bodies of water However, many other

structures are generally considered

highway bridges An overhead is a

structure carrying a highway over a

railroad, and an underpass is a structure

providing passage of a highway under a

railroad An overcrossing is a structure

carrying a county road or a city street

over a state highway, and an

undercrossing is a structure providing

passage of a county road or a city street under a state highway

A separation is a structure separating into two state highways A connector ramp is a structure connecting intersecting highways and roads An interchange is the group of ramps and structures providing connections for traffic between intersecting highways A viaduct is an elevated structure carrying a highway over streets, railroads, or other features

Highway bridges can be made of steel, concrete, timber, stone, metal alloys, or advanced composite materials, and may have different structural systems such as girder (beam), truss, arch, cable-stayed, and suspension

Design

Bridge design is a combination of art and science Conceptual design is usually the first step Before any theoretical analysis and detailed design process, the designers visualize the bridge in order to determine its function and performance.

Bridge Overcrossing

Interchange

The conceptual design process includes selection of bridge systems, materials, proportions, dimensions, foundations, aesthetics, and consideration of the surrounding landscape and environment A bridge may be straight or horizontally curved, or have skewed supports The width of a highway bridge is determined by the number and width of the traffic lanes and the shoulder or sidewalk width, and is typically the same dimension as the approaching highway.

The selection of bridge type is influenced by many factors such as span length, site geology and foundation requirements, design loads, surrounding geographical features, width requirements, clearance requirement below the bridge, transportation

of construction materials, erection procedures, and construction cost and duration The table shows the span lengths appropriate for various bridge types A bridge is required to fulfil its function as a thoroughfare while blending and harmonizing with its surroundings.

The final design process involves structural analysis, member and detail design, and preparation of construction drawings and specifications Structural analysis commonly involves computer models, which use appropriate material properties, member discretization, boundary conditions, and loads

Members and connections joints are proportioned to carry all possible loads (permanent loads, vehicular live loads, wind loads, and earthquake loads), combined and factored in accordance with the requirements of applicable design standards and codes Two standards are the American Association of State Highway and Transportation Officials Load and Resistance Factor Design (AASHTO-LRFD) Bridge Design Specifications (2004) and AASHTO Standard Specifications for Highway Bridges (2003) in the United States.

Bridge typeApplicable span range lengthLeading bridge and span lengthPrestressed concrete girder10–300 m (33–984 ft)Stolmasundet, Norway; 301 m

(988 ft)Steel I/box girder 15–376 m (49–1234 ft) Sfalassa Bridge, Italy; 376 m

(1234 ft)Steel truss40–550 m (131–1804 ft)Quebec, Canada; 549 m (1801 ft) Steel arch50–550 m (164–1804 ft)Shanghai Lupu, China; 550 m

(1804 ft)Concrete arch40–425 m (131–1394 ft)Wanxian, China; 425 m (1394 ft) [steel-tube-filled concrete]Cable-stayed110–1100 m (361–3610 ft)Sutong, China;

1088 m (3570 ft)Suspension150–2000 m (492–656 ft)Akaski-Kaikyo, Japan; 1991 m (6532 ft)

Bridge typeApplicable span range lengthLeading bridge and span lengthPrestressed concrete girder10–300 m (33–984 ft)Stolmasundet, Norway; 301 m

(988 ft)Steel I/box girder 15–376 m (49–1234 ft) Sfalassa Bridge, Italy; 376 m

(1234 ft)Steel truss40–550 m (131–1804 ft)Quebec, Canada; 549 m (1801 ft) Steel arch50–550 m (164–1804 ft)Shanghai Lupu, China; 550 m

(1804 ft)Concrete arch40–425 m (131–1394 ft)Wanxian, China; 425 m (1394 ft) [steel-tube-filled concrete]Cable-stayed110–1100 m (361–3610 ft)Sutong, China;

1088 m (3570 ft)Suspension150–2000 m (492–656 ft)Akaski-Kaikyo, Japan; 1991 m (6532 ft)

Types of bridges and applicable span length

a Read the text and circle the best answer A, B, or C

1 An overcrossing is a structure

a carrying a county road or city street over a state highway

b carrying a highway over a railroad

c providing connections for traffic between intersecting highways

2 What is the first step in bridge design is

a Theoretical analysis

b Consideration of the surrounding landscape

c Conceptual design

3 The width of a highway bridge is

a determined by the length and width of the traffic lanes

b not determined by the shoulder or sidewalk width

c the same dimension as the approaching highway

4 Which suspension bridge has the longest span?

a Sfalassa Bridge, Italy; 376 m (1234 ft)

b Shanghai Lupu, China; 550 m (1804 ft)

c Akaski-Kaikyo, Japan; 1991 m (6532 ft)

5 The final process in bridge design involves

a computer models, which use appropriate material properties

b preparation of construction drawings and specifications

c member discretization, boundary conditions, and loads

b. Read the text again and answer questions

2 Which structures are considered highways bridges?

3 What materials are highway bridges made of?

4 How long is the longest steel truss bridge?

5 What are the two standards in bridge design in the United States?

c Without looking at the text, match the terms with the definitions

Overhead   is the group of ramps and structures providing

connections for traffic between intersecting highways

Underpass   is a structure separating into two state highways

Overcrossing   is a structure carrying a highway over a railroad

Undercrossing   is an elevated structure carrying a highway over streets,

railroads, or other features

Separation   is a structure providing passage of a county road or a

city street under a state highway

4 LISTENING AND SPEAKING

Golden Gate Bridge

a Listen and complete the following note

b In pairs discuss the Golden Gate Bridge using the note above

5 VOCABULARY

CROSSWORD PUZZLE

GOLDEN GATE BRIDGE

- Has the longest (1) in the world

- Suspended road: (2) long

- (3) the San Francisco Bay to Pacific Ocean

- The project took (4) to complete

- The bridge: (5) long, (6) wide

- Two large cables pass over the top of the bridge’s (7) _

- The towers stand (8) above the water and

(9) above the road

- Each cables holds (10) strands of wire

6 WRITING

a Write a short paragraph (about 250 words) about a famous bridge in the world.

- Where is the bridge?

- When did the construction begin? How long did it take to construct the bridge?

- Why was the bridge constructed?

- What type of bridge is it?

- How long/ How wide is the bridge?

- Why is special about the bridge?

1 structure carrying the roadway above the

substructure 1 bridge supported by catenary cables

2 intermediate support for bridges 3 provides connection to intersecting

b Translate the following passage into Vietnamese:

Bridge design is a combination of art and science Conceptual design is usually the first step Before any theoretical analysis and detailed design process, the designers visualize the bridge

in order to determine its function and performance The conceptual design process includes selection of bridge systems, materials, proportions, dimensions, foundations, aesthetics, and consideration of the surrounding landscape and environment A bridge may be straight or horizontally curved, or have skewed supports The width of a highway bridge is determined by the number and width of the traffic lanes and the shoulder or sidewalk width, and is typically the same dimension as the approaching highway.

The selection of bridge type is influenced by many factors such as span length, site geology and foundation requirements, design loads, surrounding geographical features, width requirements, clearance requirement below the bridge, transportation of construction materials, erection procedures, and construction cost and duration

Unit 2 CONSTRUCTION OF ROADS AND BRIDGES

’ Back

In construction grade staking:

- blue tops (2x2x6 to 12 inch stakes) mark the level of finish grade;

- red tops (2x2x6 to 12 inch stakes) mark the level of sub-grade;

Typical arrangement of various stakes on a road section (final grading)

Blue top (Grade stake)

Red top (Grade stake)

CL

CL

Match the terms with definitions.

a. indicate required grade elevations tothe construction crews During thefinal grading stage of construction, hubs called “blue tops” are used

3 Centerline

c. are used to indicate the inside edge

of the roadway shoulders Thesestakes are set opposite each center-line stake

4 Shoulder stakes  

d. a fixed reference point that is used inthe surveying process to accuratelymeasure elevations

5 Slope stakes  

e. mark the intersection offside slopes with the natural ground surface They indicate the earthworklimits on each side of the center line

h. indicate the legal right of passage

or corridor and outmost bounds ofconstruction

Two words can cause sighs of defeat and exasperation among travelers: road

construction Yet, while road construction seems inconvenient and troublesome, in truth

it benefits the public By building and repairing roadways, people may travel long distances with relative ease, a feat that would become near impossible without passable roads Road construction in the U.S follows a standard set of procedures for longevity and usability of the future roadway

b Read the text and order the paragraphs 1-6.

Workers place blue stakes every 10-20 meters and begin to level the ground to meet thepre-mapped elevation benchmarks With the "blue tops" on the surface, contractorsperform a final touch to the earth or dirt road Then workers begin to lay an aggregate, or

a rocky, densely-packed substance, to the levelled ground as a base, followed later byasphalt and other surface dressing materials

Once the surveyors have completed mapping the area, they must next assess the groundfor road suitability Workers take soil samples from boreholes using a drill rig or handauger, with a minimum of 15 samples (borings) every kilometer These samples stretchout to 30 meters on either side of the new highway and once analyzed, lead to aclassification of the area's soil profile Swamps, lakes, rivers and other wetlands requiremore surveys and assessments, not only to determine the ecological impact of a newroadway but also to determine suitability

Over time, the new road will experience damage due to weather and use Chips willdevelop in the pavement from freezing water, encroaching plants, snow chains and more.Sometimes existing roadways need expansion to handle an increasing amount of traffic.Roads undergo repaving, repainting and more to stay in operation

Surveying

Before construction ever begins, extensive mapping and topographic survey takes place.Surveyors map the entire area to pinpoint where the new road will sit Once complete,adjacent homes are mapped and if necessary, bought out through the government's right

of eminent domain, which occurs if the property falls within the new road's right-of-way.Surveyors note the topography of the surrounding area, such as mountains, streams andlakes, and place the new road accordingly Benchmarks are mapped every 250-300meters for the entire length, referencing elevation in comparison to sea level andsignifying the future preferred elevation of the road

E Finishing Touches

Workers apply paint to the finished road and begin work on slopes and ditch bottoms totry and prevent erosion They place stakes for various erosion control materials, such asstraw and rock Workers apply paint to the new road to guide the users and identifytraveledway lanes Final measurements will determine the quality of the roadconstruction job, as well as whether the road meets legally-required standards Thesefactors play into the contractor's final pay

Once the government has completed all the mapping, property acquisition and soilstudies, actual groundwork can begin Workers place survey posts every 25-30 meters onthe new road's centerline and at the right of way limits and removal of trees and bushbegins After workers have cleared the trees and bush, they place construction stakes onthe centerline, slope stakes, stakes for culverts, storm drains and curbs

c Put the following words into the six correct categories above.

mapping survey topography construction stakes painting

benchmarks repaving cross sections property cornersswamp soundings right of way acquisition centerline reestablishment

repainting tree and bush removal

d Read again and answer the questions

1 What do surveyors do before construction begins?

2 How far is it between two benchmarks?

3 How many soil samples are taken every kilometer?

4 Why do wetlands require more surveys and assessments?

5 What do workers do after tree and bush removal?

6 When do constructors perform the final touch to the dirt road?

7 What do the workers do before paving asphalt?

8 What do workers do in the finishing touches?

9 Why do the roads require maintenance?

3 LISTENING

Watch a video about Asphalt Paving Inspection and complete the following note.

ASPHALT PAVING INSPECTION

Compaction

- Compaction makes the pavement dense

- Rolling must achieve the desired (1) , smoothness and surface texture.

- 3 phases in rolling: Breakdown, intermediate, (2) .

- Typical arrangement of vehicles:

+ Steel wheel vibratory roller in breakdown.

+ Pneumatic roller in (3) .

+ Static roller in final/finish rolling.

Inspecting tips

- Watch each roller at (4) direction.

- Rollers should process in a (5) _line

- Rollers should work at (6) speed

- On super-elevation, rolling should start at (7) _ side

- Longitude (8) _ should always roll first.

4 SPEAKING

In groups of four, discuss the characteristics of asphalt pavement and PCC (Portland Cement Concrete) pavement using comparative adjectives.

Students A: List 5 advantages of Asphalt Pavement over PCC Pavement

Students B: List 5 advantages of PCC Pavement over Asphalt Pavement

Characteristics of Asphalt Pavement and PCC

Pavement

(Source: Guidelines on Expressways in Japan – Kosoku Doro Chosaika)

Items Asphalt Concrete Pavement PCC Pavement

Less noise and vibration Vibration caused at joints, and

noise due to harsh or rough texture are sometimes problems

Brightness of

Surface Reflectance of the surface islower than PCC, which causes

difficulty in driving through tunnels

Lighter after dark or inside tunnels

Large number of construction equipment items, which inevitably tends to produce restriction as below Production rate is also lower.

- Subgrade preparation should

be successively done.

- Structures like bridges and culverts should be fewer in number Pavement usually provided with asphalt wearing course.

should be avoided.

Cost Analysis Initial cost is cheaper, but

frequent repair is required and total cost over 20 years or so is sometimes higher.

Initial cost is higher Reconstruction is more expensive

Unit 2 CONSTRUCTION OF ROADS AND BRIDGES

1 VOCABULARY BUILDING

Bridge Construction Methods

a Precast Concrete Bridges

Precast I Beams & Supper Tee’s

- Standard beams can be pre and/ or

Precast Segmental Techniques

- Complete deck cast, delivered and

erected in unique cells

- Segments are prestressed together

using external and/or internal

tendons

- Joints can be “dry” or “wet”

- Typically in span by Span or

Balanced Cantilever mode

- Structurally efficient and aesthetic

- Complete with deck when erected (rapid and safe)

- Cast during substructure work (overlap activities)

- Need space for cast yard

- Difficult to transport

Figure 2 Erection on Falsework Figure 3 Erection by Gantry (span by span) Figure 4 Erection by Gantry (Balanced Cantilever)

Figure 5 Erection by Crane Figure

6 Erection by Lifting frame

Figure 7,8: Balanced Cantilever (Segmental cast

in-situ)

Figure 9,10: Incremental Launching Method (Cast in-situ)

b Fill in the blank with suitable word(s) from the table below Some words can be

use more than once Retaining wall

2 READING

THE AKASHI-KAIKYO SUSPENSION BRIDGE – JAPAN

By V Ryan

The Akashi Kaikyo Suspension Bridge is the

longest suspension bridge in the world and it is

probably Japan’s greatest engineering feat.

It took two million workers ten years to

construct the bridge, 181,000 tonnes of steel

and 1.4million cubic metres of concrete The

steel cable used would circle the world seven

times.

It has six lanes and links the island of Awaji

and the mainland city of Kobe, a distance of

four miles The concept of building a bridge

across the Akashi Straits became urgent after

a disaster in 1955 A ferry carrying over one

hundred children sank after colliding with

another ferry, in the busy shipping lane One

hundred and sixty eight children and adults

died in the disaster Political pressure for a

bridge increased and in 1988 construction

began.

The Akashi Straits is four miles wide at the bridge site with sea depths of one hundred metres and currents averaging fourteen kph The Akashi Straits is one of the busiest sea lanes in the world with over a thousand ships per day travelling through it Furthermore, the bridge is in a typhoon region in which winds can reach speeds of 290 kph

S UB

S TR

U C TU RE

S UP ER

S TR

U C TU RE

stretching between two towers The roadway beneath these is suspended by more cables To stop the towers, roadway and cables collapsing, they are held at either end by large anchor blocks (the Akashi anchor blocks weigh

350 000 tonnes) In the case of the Akashi-Kaikyo Bridge, suspension bridge technology was pushed to the limit.

The Japanese designers and engineers tested their designs by building complex models These were tested in wind tunnels which helped them refine the design so that the bridge could cope with severe weather and typhoon conditions After vigorous testing had taken place, construction of the real bridge could begin.

The two towers stand on two large circular foundations The moulds for the two foundations were built in dry dock weighing 15 000 tonnes and 60 metres in height In March 1989 a major stage of construction was reached with the moulds for the foundations to the towers being towed out to their positions in the sea by numerous tugs When in position the moulds were flooded with two hundred and fifty million litres of water, taking eight hours

to complete By the time the moulds were full, they were resting on the sea bed.

In 1989 work on the two towers began Each is nearly as high as the Eiffel Tower and is designed to have a two hundred year lifespan The towers are

283 metres in height and if the foundations are included, this adds a further

60 metres.

Each tower is made up of 90 sections and they were built with absolute precision as the design allowed only a 25mm offset at the top In order to achieve this level of accuracy each of the blocks were ‘surface ground’ to a precise finish 700 000 bolts were used to fix each of the towers together.

Each tower is designed to flex / move in storm force conditions They and even have a special mechanism that counteracts and dampens movement.

When the towers were completed a

temporary cable was stretched between

both and a wire mesh gangway built so

that workers could start construction of

the main cables This temporary

gangway can be seen in the photograph

to the right Workers and machinery

pulled the main cables from one tower to

the other.

Once the main cables and the vertical

cables were in position the deck /

roadway was fixed hanging below them.

This work took place in 1994 Large

purpose built cranes were used to lift the

sections, 4000 tonnes each, were bolted

into position, one after another 290

sections make up the entire bridge.

The photographs to the right show the

cranes in operation and the deck as it

was fixed in position, section by section.

Each section has a triangulated form This means that weight is kept to a minimum and yet each section has maximum strength.

The final section of the deck was bolted in position in September 1998 and the bridge was opened to the public on the 5th of April of the same year.

a Read the text and answer the following questions

1 How long did it take to build the Akashi-Kaikyo Suspension Bridge?

2 Why was the bridge built?

3 When did the construction of the bridge begin?

4 What are used to prevent the towers, roadway and cables from collapsing?

5 Why do you think it is important to make models of complex structures beforetheir full scale construction?

6 When was the major stage of construction reached?

7 What is special about the towers of the Akashi-Kaikyo Suspension Bridge?

8 How long are the two towers expected to last for?

9 How many bolts were used to fix each of the tower together?

10 When was the bridge opened?

b Without looking at the text, in pairs, can you remember what these numbers refer to?

90 2,000,000 15,000 200 4 168 60 283 7 350,000 700,0004,000 181,000 1,400,000 1998

3 LISTENING

Phu My Bridge

a In groups of three, discuss the following questions

- Look at the following pictures, do you know what is the type of these bridge?

- What do you know about Phu My bridge?

b. Watch a video about Phu My bridge and choose the best answer for the following questions

1 Which river does the Phu My bridge span?

a the central to Northern part of Vietnam

b the Southern Mekong Delta to the central and Northern part of Vietnam