Bài giảng Tiếng Anh Chuyên ngành giao thông Đại học Công Nghệ GTVT (UTT)Unit 2part 1

Unit 2
PART 1
1.

CONSTRUCTION OF ROADS AND BRIDGES
ROAD/HIGHWAY CONSTRUCTION

VOCABULARY BUILDING

Highway Surveys
1. In pairs, guess the meaning of the following terms.

Benchma
rk
Aggrega
te
A man standing at the benchmark point


Soil
boring
sample

Surveyors take soil boring sample using a drill rig or a hand auger

cL
6’

Front
cL’

Back

78+00

Right-of-way and centerline stakes

F
60

Centerline Stakes

cL

26.0
16.0

6.0

4.0

4.0

Front’

Marking and setting slope stakes

C
40
260

cL

78+00

Slope
stake

Back

1:1

Marking and placement of slope stakes


Red top
(Grade
stake)

Blue top
(Grade
stake)

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 subgrade;

CL
1+00

0+00

CL


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


Match the terms with definitions.



indicate required grade elevations to the construction
 crews. During the final grading stage of construction,
hubs called “blue tops” are used in lieu of stakes.

Soil
boring

samples

Stone and gravel of various sizes which compose the major
 portion of the surfacing material. The sand or pebbles
added to cement in making concrete.

Centerline
stakes



are used to indicate the inside edge of the roadway
 shoulders. These stakes are set opposite each center-line
stake.

Shoulder
stakes



a fixed reference point that is used in the surveying process
 to accurately measure elevations.

Slope stakes



mark the intersection offside slopes with the natural
 ground surface. They indicate the earthwork limits on
each side of the center line.

Right-of-way
stakes







are taken by drilling down into the ground to determine the

 soil composition before or during construction.





Benchmark

Grade stakes
Aggregate

indicate the exact center of the roadway construction.

indicate the legal right of passage or corridor and
outmost bounds of construction.


2.

READING

a. Have you ever visited a highway construction site? What can you see on
a highway construction site?

Highway Construction Procedures
By Amanda Holden
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.
A

Levelling and Paving

Workers place blue stakes every 10-20 meters and begin to level the ground to
meet the pre-mapped elevation benchmarks. With the "blue tops" on the
surface, contractors perform 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 by asphalt and other surface dressing
materials.
B

Ground Assessment

Once the surveyors have completed mapping the area, they must next assess
the ground for road suitability. Workers take soil samples from boreholes using
a drill rig or hand auger, with a minimum of 15 samples (borings) every
kilometer. These samples stretch out to 30 meters on either side of the new
highway and once analyzed, lead to a classification of the area's soil profile.
Swamps, lakes, rivers and other wetlands require more surveys and
assessments, not only to determine the ecological impact of a new roadway but
also to determine suitability.
C

Maintenance

Over time, the new road will experience damage due to weather and use. Chips
will develop 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.
D 1

Mapping and 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 and lakes, and place the new road
accordingly. Benchmarks are mapped every 250-300 meters for the entire
length, referencing elevation in comparison to sea level and signifying 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 to try and prevent erosion. They place stakes for various erosion
control materials, such as straw and rock. Workers apply paint to the new road
to guide the users and identify traveledway lanes. Final measurements will

determine the quality of the road construction job, as well as whether the road
meets legally-required standards. These factors play into the contractor's final
pay.
F

Earthwork

Once the government has completed all the mapping, property acquisition and
soil studies, actual groundwork can begin. Workers place survey posts every
25-30 meters on the new road's centerline and at the right of way limits and
removal of trees and bush begins. After workers have cleared the trees and
bush, they place construction stakes on the centerline, slope stakes, stakes for
culverts, storm drains and curbs.
c. Put the following words into the six correct categories above.
mapping survey
alignment
survey

topography
paving

construction stakes
erosion control

painting
soil

benchmarks
corners

repaving

cross sections

property

swamp soundings

right of way acquisition

repainting

tree and bush removal

centerline reestablishment


Mapping
and
Surveying
Mapping
survey

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?

PAVING
6. When do constructorsASPHALT
perform the final
touch to the INSPECTION
dirt road?
Compaction

7. What
do the workers
do before
paving asphalt?
- Compaction
makes
the pavement
dense

- Rolling must achieve the desired (1)____________, smoothness and surface
texture.
- 3dophases
in rolling:
Breakdown, intermediate, (2)____________.
9. Why
the roads
require maintenance?
- Typical arrangement of vehicles:
3. LISTENING
+ Steel wheel vibratory roller in breakdown.
+ Pneumatic roller in (3)____________.
Watch a video
about

Pavingrolling.
Inspection and complete the
+ Static
rollerAsphalt
in final/finish
following
note. tips
Inspecting
- 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.
8. What do workers do in the finishing touches?



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

Design Period

10 years

Resistance to
Deformation
and Abrasion

Less
resistant
against Deformation such as rutting is
deformation, causing rutting. hardly observed.

Noise
Vibration

20 years

Less resistant to abrasive Highly resistant to abrasion in
forces generated with studded general.
tires

and Less noise and vibration

Vibration caused at joints, and

noise due to harsh or rough
texture
are
sometimes
problems

Brightness
Surface

of Reflectance of the surface is Lighter after dark or inside
lower than PCC, which causes tunnels
difficulty in driving through
tunnels

Evenness
Surface

of Normally better than PCC

Restrictive
Conditions in
Construction

Fewer restrictive conditions
during construction work, and
production rate is normally
higher.

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.

Maintenance
and
Rehabilitation

Possible and easy with simple Comparatively large scale
methods.
methods should be employed,
so that PCC on soft ground
should be avoided.

Cost Analysis

Initial cost is cheaper, but Initial
cost
frequent repair is required and Reconstruction
total cost over 20 years or so is expensive.
sometimes higher.

is
is

higher.
more