Where I emailprotected#%* …Bank of China Tower
Bank of China Tower, known as the tallest building in Hong Kong and Asia
from 1989 to 1992, is 1,209-foot and it is a fitting building. The “Tower”
sits in the central business district, a ribbon of land densely packed with
banks and office buildings squeezed between mountain and harbor. It is one
of the busiest, crowded, active, frenetic cities in the world. After
experiencing it, I was attracted by its visual context and its special
features, as this modern building has a flexible layout, reflective
glasses, sustainability in architectural design……etc
I.M. Pei, the architect of Bank of China Tower, tends to use large,
abstract forms and sharp, geometric designs. His glass clad structures
seem to spring from the high tech modernist movement. His reliance on
abstract form and materials such as stone, concrete, glass, and steel, has
been considered a disciple of Walter Gropius. Nevertheless, he is more
concerned with function than theory. Pei wanted to create a structure that
would represent the aspirations of the Chinese people and symbolize good
will toward the British people. His buildings are a unique testament to
how the convergence of two great traditions, the Asian and the European,
can create new aesthetic standards – timelessness in stone and glass. He
has used the urban, modern style to create the building, such as steel
frame and glass curtain wall. Bank of China Tower is the most noticeable
building in Hong Kong, not only the number of stories but is also the only
building that stands out from the rest of the other buildings because of it
Here come details of the Bank of China:
|Glass Skyscraper |
First of all, let us look back to 1883, William Le Baron Jenney invented
the first “skyscraper construction” building, in which a metal structural
skeleton supports an exterior wall on metal shelves (the metal frame or
skeleton, a sort of three-dimensional boxlike grid, is still used today).
His earliest surviving metal-skeleton structure, the Second Leiter Building
of 1891, stands at the southeast corner of State and Van Buren streets in
the Loop. The granite-face facade is extremely light and open, suggesting
the metal frame behind. The building looks so modern that it comes as a
shock to realize it is more than a century old. On the other hand, Ludwig
Mies van der Rohe’s structural and spatial concepts are analyzed through
his three major building prototypes, specifically the skeleton frame
building, both in its high- and low-rise manifestations, and the clear-span
building. His most important projects are also examined, not only as
isolated functions, but within the context of urban space. The ‘Seagram’
building in New York, hailed as a masterpiece of skyscraper design, which
profoundly influenced the form and architecture of the office building, and
the open space in the city. The extruded metal and glass curtain wall of
Seagram and its use of tinted glass became widely replicated. After the
Seagram building was completed and it encourages street-level open space in
association with high-rise buildings.
According to Ken Yeang, skyscraper, as a city-in-the-sky, in a novel design
approach that resembles urban design and planning as against the design of
a conventional building in a high-rise structure. It is a new vertical
theory of urban design. It also suggests ideas for the diversification of
vertical land uses, the creation of public realms and places-in-the-sky,
vertical landscaping, creating high-rise neighborhoods, vertical townscape,
vertical transportation and accessibility.
Structure engineer Leslie Robertson describes the tubes as “bundled
vertical space trusses.” Almost the entire gravity load of the building
flows through the structural diagonals behind the “Xs” of the facade to
four corner columns. There is a fifth central column that splits into a
tetrahedron at the twenty-fifth floor with branching legs that pass
interior loads to the comer columns adding stability close to the base and
the great clear span of the lobby.
The diagonals, intermediate minor columns and beams, and stiffening trusses
in different planes are framed into the primary comer columns. The
composite action steel and concrete comers lock the structural elements
into a space frame structure, and this is what sets this building apart
The “Tower” is sustainability in architectural design. Reduce in energy
consumption is not the only strategy of sustainable design. The resources
/ materials conservation as well as the environmentally pleasant design are
good examples that can be observed in Bank of China Tower. Five principal
columns hold up the 70-storey building with one at each of its four corners
risen to different heights and a central column transferring loads down
from the tower top to the 25th floor and then diagonally out to the corner
columns. This structural system requires less major diagonal elements and
lighter structural membering. Reinforced concrete, instead of complex and
expensive welded steel connection, was the element to envelop the joint at
which vertical, horizontal and diagonal members of the steel frame come
together from different angles. The 3-dimensional space truss together
with the concrete joint let the tower use only 60% as much steel as a
conventional skyscraper frame normally has used.
It has a flexible layout. The triangularly trussed 3-dimensional structure
gives column-free interior space that allows future change in office
layout. This saves energy and resources.Talking about the lighting,
atrium and the inclined roofs (skylight) allow more natural lighting and
therefore save energy for artificial lighting: The 15-storey atrium running
from the ground floor to the building’s first sloped roof makes possible
the diffuse of natural light down to the banking hall. “Sky lounge” on the
70th floor topped by an inclined triangular cap is also flooded by natural
The building is covered by reflective glasses. The whole building is
enclosed by silver-coated reflective glass framed in natural anodized
aluminum. Such skin not only reflects the images of changing sky and city,
but also the bright sunlight so that heat gain and cooling loads (i.e.
energy consumption) were effectively reduced.
Masking effect of water gardens is found, the whole building has rotated by
45 degree, forming triangular spaces (water gardens) at either side of the
entrance. The flowing water helps to muffle the noise from the busy traffic
roads nearby and makes the entrance area more environmental friendly and
Composite design allows the geometry of the structure to be molded to the
geometry of the facade. Pei insisted that the corners of the facade
diagonals come to a point at the absolute edge of the building. The
aluminum cladding does just that. Behind the virtuoso precision of the
curtain wall, the structure does what it has to do to hide itself.
The building rises as a great cantilever out of the ground that must
withstand lateral forces as a horizontal cantilever withstands vertical
forces. In Hong Kong these are considerable. The tower will withstand
double the wind loads of New York City – typhoon winds of 143 mph at the
top and four times the equivalent earthquake load of Los Angeles.
Cantilever loads are greatest at the fixed end. The foundation is cast-in-
place hand-dug concrete caissons with perimeter concrete diaphragm walls.
The base of the Bank of China Tower is stabilized by two steel-plate shear
tubes. These surround the service cores from foundation to fourth floor.
Steel plates are generally less than one-half inch thick. These provide
the whole lateral force system from story four down. The shear cores
include the elevators aid the bank vault areas where the steel is covered
by over three feet of concrete. There are thinner concrete overlays
elsewhere on the steel-plate shear tubes for interior building cladding.
The “Tower” was very much an international effort. “Green coated”
reinforcing bars, used in selected areas of the building to combat
electrolytic action, were a “first” in Hong Kong. The bars were purchased
in China, shipped to Abu Dhabi for epoxy coating and then to Hong Kong.
The curtain wall was bid by firms in West Germany, Japan, and the United
States. The West German firm won the contract.
The building turns to different colors as the day goes by. Because of its
steel frame and glass curtain wall, it reflects the day light. In the
morning, the building’s color is glossy sky blue and at night is both black
and gray with some night lights reflected from other building’s lights.
While visually striking as a sculptural form, the tower was also an
engineering breakthrough. By using an enormous version of a conventional
three-dimensional truss as the basic structure, Pei was able to transfer
stress to the four corners of the building, making it far more stable than
it would have been if built according to the column-and-beam method.
The Bank of China Tower differs in structural concept from the traditional
buildings around it and looks it. It is not politely nor politically
contextual. It stands out as what it is, an ingenious architectural and
structural solution symbolizing the Republic of China.
The two are entirely different building concepts with little basis for
comparison. Foster’s Hong Kong Bank is a highly hand- and machine-crafted
jewel. It is tied into the great money market electronic network of world
finance. The Bank of China Tower is a branch bank building in which most
of the space is for rent, a commercial building. The Bank of China will
occupy floors one through seventeen and sixty-eight through seventy. Fifty-
one floors are “spec. space” designed to be competitive on the Hong Kong
The Bank of China Tower is very much a building of our time. The Empire
State Building and the Chase Manhattan Bank Building were designed before
computers entered the building field to make number crunching cheap. At
that time building forms were often changed to fit calculations. Ideas
were discarded because they were too expensive to calculate.
For years, as steel and concrete increased in strength, the changes were
incorporated into building thinking as only improved versions of weaker
steel and concrete. Their design was limited by conventional thinking.
Columns could be made a bit smaller but no matter how much the strength of
steel is increased the modulus of elasticity (stiffness) changes very
little. This means it becomes a better tensile material but not a great
deal improved to withstand bending. Concrete has the opposite
characteristic. Its compressive strength increases its tensile properties
only grow as the square root of its compressive strength.
The Bank of China at least involved fung shui. The people, representing an
officially atheistic society were steadfastly opposed to the practice and
refused to have the traditional analysis done. Not surprisingly, freelance
advice began to proliferate almost as soon as the design was made public.
As if the unhappy history of the site was not curse enough, the local
geomancers noted that the masts stop the tower could be interpreted either
as chopsticks held vertically in an empty rice bowl, or as the sticks of
incense used to memorialize of the dead. Far worse were the X’s made by
the cross bracing that was to be expressed on the facades. Local
authorities noted immediately that, at best, the X’s evoked the mark
traditionally drawn on a failing student’s exercise by a calligraphy
instructor. At worst, they suggested the custom of hanging a name tag
around a condemned man’s neck and slashing an X through it to signify that
he was “finished”.
Coping with the unusual shape was a powerful motivation, an inspiration, in
the development of this new concept. The system is now tested and ready
for application to a wide variety of building systems.
It shows how the bank of china is joined together in 3 dimensions
One has the impression it was over designed and excessively detailed. In
contrast a structure as elegantly rational as the Bank of China Tower fits
together in any language. So, Bank of China Tower is worthwhile to have
further investigations. I have tried to discover what I have experienced,
instead of observing some architecture I have never seen before.
Donovan, M. (2001)The architecture of I.M.PEI. Lordon: HarryN.Abrams,
Whitney, J (1953) The Museum of Modern Art, New York: The Museum
Von Boehm G (1990) Conversations with I.M.PEI Light is the key, New York
Betsky, A (1992) Architecture and Medicine: I.M. Pei designs the
Kirlin Clinic. University of Alabama Health Services Fenestration at
the University at Birminham Medical Center: University Press of America
Pei I M (1963) Urban Renewal in Southwest Washington. AIA Journal
Wiseman, C (1990) A Profile in America Architecture. New York: H.N.Abrams
Engles H (2001)Bauhaus Architecure. New York: Prestal Verlag