WHY PAGODAS DON’T FALL DOWN?
In a land swept by typhoons and shaken by earthquakes,
how has Japan's tallest and seemingly flimsiest old buildings - 500 or so
wooden pagodas-remained standing for centuries? Records show that only two have
collapsed during the past 1400 years. Those that have disappeared were
destroyed by fire as a result of lightning or civil war. The disastrous Hanshin
earthquake in 1995 killed 6,400 people, toppled elevated highways, flattened
office blocks and devastated the port area of Kobe. Yet it left the magnificent
five-storey pagoda at the Toji temple in nearby Kyoto unscathed, though it
levelled a number of buildings in the neighbourhood.
Japanese
scholars have been mystified for ages about why these tall, slender buildings
are so stable. It was only thirty years ago that the building industry felt
confident enough to erect office blocks of steel and reinforced concrete that
had more than a dozen floors. With its special shock absorbers to dampen the
effect of sudden sideways movements from an earthquake, the thirty-six-storey
Kasumigaseki building in central Tokyo-Japan's first skyscraper–was considered
a masterpiece of modern engineering when it was built in 1968.
Yet in 826, with only pegs and wedges to keep his
wooden structure upright, the master builder Kobodaishi had no hesitation in
sending his majestic Toji pagoda soaring fifty-five meters into the sky-nearly
half as high as the Kasumigaseki skyscraper built some eleven centuries later.
Clearly, Japanese carpenters of the day knew a few tricks about allowing a
building to sway and settle itself rather than fight nature's forces. But what
sort of tricks?
The multi-storey pagoda came to Japan from China in
the sixth century. As in China, they were first introduced with Buddhism and
were attached to important temples. The Chinese built their pagodas in brick or
stone, with inner staircases, and used them in later centuries mainly as watchtowers.
When the pagoda reached Japan, however, its architecture was freely adapted to
local conditions they were built less high, typically five rather than nine
storeys, made mainly of wood and the staircase was dispensed with because the
Japanese pagoda did not have any practical use but became more of an art
object. Because of the typhoons that batter Japan in the summer, Japanese
builders learned to extend the eaves of buildings further beyond the walls.
This prevents rainwater gushing down the walls. Pagodas in China and Korea have
nothing like the overhang that is found on pagodas in Japan.
The roof of a Japanese temple building can be made to
overhang the sides of the structure by fifty percent or more of the building's
overall width. For the same reason, the builders of Japanese pagodas seem to
have further increased their weight by choosing to cover these extended eaves
not with the porcelain tiles of many Chinese pagodas but with much heavier
earthenware tiles.
But this does not totally explain the great resilience
of Japanese pagodas. Is the answer that, like a tall pine tree, the Japanese
pagoda with its massive trunk-like central pillar known as shinbashira simply
flexes and sways during a typhoon or earthquake) For centuries, many thought
so. But the answer is not so simple because the startling thing is that the
shinbashira actually carries no load at all. In fact, in some pagoda designs,
it does not even rest on the ground, but is suspended from the top of the
pagoda-hanging loosely down through the middle of the building. The weight of
the building is supported entirely by twelve outer and four inner columns.
And what is the role of the shinbashira, the central
pillar? The best way to understand the shinbashira's role is to watch a video
made by Shuzo Ishida, a structural engineer at Kyoto Institute of Technology.
Mr Ishida, known to his students as 'Professor Pagoda' because of his passion
to understand the pagoda, has built a series of models and tested them on a
'shaketable' in his laboratory. In short, the shinbashira was acting like an
enormous stationary pendulum. The ancient craftsmen, apparently without the
assistance of very advanced mathematics, seemed to grasp the principles that
were, more than a thousand years later, applied in the construction of Japan's
first skyscraper. What those early craftsmen had found by trial and error was
that under pressure a pagoda's loose stack of floors could be made to slither
to and fro independent of one another. Viewed from the side, the pagoda seemed
to be doing a snake dance with each consecutive floor moving in the opposite
direction to its neighbours above and below. The shinbashira, running up
through a hole in the centre of the building, constrained individual storeys
from moving too far because, after moving a certain distance, they banged into
it, transmitting energy away along the column.
Another strange feature of the Japanese pagoda is
that, because the building tapers, with each successive floor plan being
smaller than the one below, none of the vertical pillars that carry the weight
of the building is connected to its corresponding pillar above. In other words,
a five storey pagoda contains not even one pillar that travels right up through
the building to carry the structural loads from the top to the bottom. More
surprising is the fact that the individual storeys of a Japanese pagoda, unlike
their counterparts elsewhere, are not actually connected to each other. They
are simply stacked one on top of another like a pile of hats. Interestingly,
such a design would not be permitted under current Japanese building
regulations.
And the extra-wide eaves? Think of them as a tight
rope walker balancing pole. The bigger the mass at each end of the pole, the
easier it is for the tightrope walker to maintain his or her balance. The same
holds true for a pagoda. 'With the eaves extending out on all sides like
balancing poles,' says Mr. Ishida, 'the building responds to even the most
powerful jolt of an earthquake with a graceful swaying, never an abrupt
shaking. Here again, Japanese master builders of a thousand years ago
anticipated concepts of modern structural engineering.
Questions 1-4
Do the following statements agree with the claims of the writer in Reading Passage 143?
In boxes 1-4 on your answer sheet, write
TRUE if the statement agrees with the claims of the writer
FALSE if the statement contradicts the claims of the writer
NOT GIVEN if there it impossible to say what the writer thinks about this
Do the following statements agree with the claims of the writer in Reading Passage 143?
In boxes 1-4 on your answer sheet, write
TRUE if the statement agrees with the claims of the writer
FALSE if the statement contradicts the claims of the writer
NOT GIVEN if there it impossible to say what the writer thinks about this
1 Only two Japanese pagodas have collapsed in 1400
years.
2 The Hanshin earthquake of 1995 destroyed the pagoda at the Toji temple.
3 The other buildings near the Toji pagoda had been built in the last 30 years.
4 The builders of pagodas knew how to absorb some of the power produced by severe weather conditions.
2 The Hanshin earthquake of 1995 destroyed the pagoda at the Toji temple.
3 The other buildings near the Toji pagoda had been built in the last 30 years.
4 The builders of pagodas knew how to absorb some of the power produced by severe weather conditions.
Questions 5-10
Classify the following as typical of
Classify the following as typical of
A. both Chinese and Japanese pagodas
B. only Chinese pagodas
C. only Japanese pagodas
B. only Chinese pagodas
C. only Japanese pagodas
Write the correct letter, A, B or C, in boxes 5-10 on your answer sheet.
5 easy interior access to top
6 tiles on eaves
7 use as observation post
8 size of eaves up to half the width of the building
9 original religious purpose
10 floors fitting loosely over each other
5 easy interior access to top
6 tiles on eaves
7 use as observation post
8 size of eaves up to half the width of the building
9 original religious purpose
10 floors fitting loosely over each other
Questions 11-13
Choose the correct letter, A, B or C.
Write the correct letter in boxes11-13 on your answer sheet.
11 In a Japanese pagoda, the shinbashira
A bears the full weight of the building.
B bends under pressure like a tree.
C connects the floors with the foundations.
D stops the floors moving too far.
Choose the correct letter, A, B or C.
Write the correct letter in boxes11-13 on your answer sheet.
11 In a Japanese pagoda, the shinbashira
A bears the full weight of the building.
B bends under pressure like a tree.
C connects the floors with the foundations.
D stops the floors moving too far.
12 Shuzo Ishida performs experiments in order to
A improve skyscraper design.
B be able to build new pagodas.
C learn about the dynamics of pagodas.
D understand ancient mathematics.
A improve skyscraper design.
B be able to build new pagodas.
C learn about the dynamics of pagodas.
D understand ancient mathematics.
13 The storeys of a Japanese pagoda are
A linked only by wood.
B fastened only to the central pillar.
C fitted loosely on top of each other.
D joined by special weights.
A linked only by wood.
B fastened only to the central pillar.
C fitted loosely on top of each other.
D joined by special weights.
Click the button to Show/ Hide Answers
Answer:
1. TRUE
2. FALSE
3. NOT GIVEN
4. TRUE
5. B
6. A
7. B
8. C
9. A
10. C
11. D
12. C
13. C
1. TRUE
2. FALSE
3. NOT GIVEN
4. TRUE
5. B
6. A
7. B
8. C
9. A
10. C
11. D
12. C
13. C
