CAMBRIDGE IELTS 1
PRACTICE TEST 4
READING
READING PASSAGE 1
You should spend about 20 minutes on Questions
1-13 which are based on Reading Passage 1 below
AIRPORTS ON WATER
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River deltas
are difficult places for map makers. The river builds them up, the sea wears
them down; their outlines are always changing. The changes in China’s Pearl
River delta, however, are more dramatic than these natural fluctuations. An
island six kilometres long and with a total area of 1248 hectares is being
created there. And the civil engineers are as interested in performance as in
speed and size. This is a bit of the delta that they want to endure.
The new
island of Chek Lap Kok, the site of Hong Kong’s new airport, is 83% complete.
The giant dumper trucks rumbling across it will have finished their job by
the middle of this year and the airport itself will be built at a similarly
breakneck pace.
As Chek Lap
Kok rises, however, another new Asian island is sinking back into the sea.
This is a 520-hectare island built in Osaka Bay, Japan, that serves as the
platform for the new Kansai airport. Chek Lap Kok was built in a different
way, and thus hopes to avoid the same sinking fate.
The usual
way to reclaim land is to pile sand rock on to the seabed. When the seabed
oozes with mud, this is rather like placing a textbook on a wet sponge: the
weight squeezes the water out, causing both water and sponge to settle lower.
The settlement is rarely even: different parts sink at different rates. So
buildings, pipes, roads and so on tend to buckle and crack. You can engineer
around these problems, or you can engineer them out. Kansai took the first
approach; Chek Lap Kok is taking the second.
The
differences are both political and geological. Kansai was supposed to be
built just one kilometre offshore, where the seabed is quite solid. Fishermen
protested, and the site was shifted a further five kilometres. That put it in
deeper water (around 20 metres) and above a seabed that consisted of 20
metres of soft alluvial silt and mud deposits. Worse, below it was a
not-very-firm glacial deposit hundreds of metres thick.
The Kansai
builders recognised that settlement was inevitable. Sand was driven into the
seabed to strengthen it before the landfill was piled on top, in an attempt
to slow the process; but this has not been as effective as had been hoped. To
cope with settlement, Kansai’s giant terminal is supported on 900 pillars.
Each of them can be individually jacked up, allowing wedges to be added
underneath. That is meant to keep the building level. But it could be a
tricky task.
Conditions
are different at Chek Lap Kok. There was some land there to begin with, the
original little land of Chek Lap Kok and a smaller outcrops of hard,
weathered granite make up a quarter of the new island’s surface area.
Unfortunately, between the islands there was a layer of soft mud, 27 metres
thick in places.
According to
Frans Uiterwijk, a Dutchman who is the project’s reclamation director, it
would have been possible to leave this mud below the reclaimed land, and to
deal with the resulting settlement by the Kansai method. But the consortium
that won the contract for the island opted for a more aggressive approach. It
assembled the world’s largest fleet of dredgers, which sucked up 150m cubic
metres of clay and mud and dumped it in deeper waters. At the same time, sand
was dredged from the waters and piled on top of the layer of stiff clay that
the massive dredging had laid bare.
Nor was the
sand the only thing used, the original granite island which had hills up to
120 metres high was drilled and blasted into boulders no bigger than two
metres in diameter. This provided 70m cubic metres of granite to add to the
island’s foundations. Because the heap of the boulders does not fill the
space perfectly, this represents the equivalent of 105m cubic metres of
landfill. Most of the rock will become the foundations for the airport’s
runways and its taxiways. The sand dredged from the waters will also be used
to provide a two-metre capping layer over the granite platform. This makes it
easier for utilities to dig trenches-granite is unyielding stuff. Most of the
terminal buildings will be placed above the site of the existing island. Only
a limited amount of pile-driving is needed to support building foundations
above softer areas.
The
completed island will be six to seven metres above sea level. In all, 350m
cubic metres of material will have been moved. And much of it, like the
overloads, has to be moved several times before reaching its final resting
place. For example, there has to be a motorway capable of carrying 150-tonne
dump-trucks; and there has to be a raised area for the 15,000 construction
workers. These are temporary, they will be removed when the airport is
finished.
The airport,
though, is here to stay. To protect it, the new coastline is being bolstered
with a formidable twelve kilometres of sea defences. The brunt of typhoon
will be deflected by the neighbouring island of Lantau; the sea walls should
guard against the rest. Gentler but more persistent bad weather – the
downpours of the summer monsoon – is also being taken into account. A mat-like
material called geotextile is being laid across the island to separate the
rock and sand layers. That will stop sand particles from being washed into
the rock voids, and so causing further settlement. This island is being built
never to be sunk.
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Questions 1-5
Classify the following statements as
applying to
A
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Chek Lap Kok
airport only
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B
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Kansai
airport only
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C
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Both
airports
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Write the appropriate
letters A-C in boxes 1-5 on your answer sheet
Example Answer
Built on a man-made island C
1
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having an area of over 1000 hectares
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2
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built
in a river delta
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3
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built
in the open sea
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4
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built
by reclaiming land
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5
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built
using conventional methods of reclamation
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Questions 6-9
Complete the labels on Diagram B below.
Choose your answers from the box below
the diagram and write them in boxes 6-9 on your answer sheet.
NB: There are more words/phrases than
spaces, so you will not use them all.
DIAGRAM
A
Cross-section
of the original areas around Chek Lap Kok before work began.
DIAGRAM
B
Cross-section
of the same area at the time the article was written.
granite
mud
Terminal
building site
sand
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runways
and taxiways
water
stiff
clay
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Questions 10-13
Complete the summary below.
Choose your answers from the box below
the summary and write them in boxes 10-13 on your answer sheet.
NB There are more words than spaces, so
you will not use them all.
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Answer
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When
the new Chek Lap Kok airport has been completed the raised area and the ____
(Example) ___________ will be removed.
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Motorway
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The island will be partially protected
from storms by _____ (10) ______ and also by _____ (11) ______. Further
settlement caused by _____ (12) ______ will be prevented by the use of _____
(13) ______.
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Construction
workers
geotextile
rainfall
sea
walls
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coastline
Lantau
Island
rock
and sand
typhoons
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dump-trucks
motorway
rock
voids
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ANSWER
KEY
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