AR375 Structural System in Architecture

Skyscraper Building

Roof

Moment Resisting Frame

Seismic Resisting System

Special Designed System

Wall and Shear Wall

Bearing wall

Beam

Slab (Floor)

Column

Footing and Foundation

Building Structural System

Skyscraper Building

A skyscraper is a tall, continuously habitable building of many stories,

usually designed for office and commercial use. There is no official

definition or height above which a building may be classified as a

skyscraper.

A relatively small building may be considered a skyscraper if it protrudes

well above its built environment and changes the overall skyline. The

maximum height of structures has progressed historically with building

methods and technologies and thus what is today considered a

skyscraper is taller than before.

Skyscraper Building

Skyscraper Building

Lately, the term supertall has arisen for the current generation of tall

buildings with a structural height of 300 m and more. The CTBUH has now

added the term megatall, for buildings with a height of 600 m and more.

Although great heights are now being achieved with built tall buildings—

in excess of 800 m (2,600 ft)—at the mid-point of 2011 there [were] only

approximately 54 buildings in excess of 300 m (980 ft) completed and

occupied globally.

The Council on Tall Buildings and Urban Habitat (CTBUH)

Skyscraper Building

Pre-19th century

The Two Towers of

Bologna in the 12th

century reached

97.2 m (319 ft) in height.

The Great Pyramid of Giza in ancient Egypt built in

the 26th century BCE was 146 m (479 ft).

Skyscraper Building

Early skyscrapers

In 1852 Elisha Otis introduced the

safety elevator, allowing convenient

and safe passenger movement to

upper floors. Another crucial

development was the use of a steel

frame instead of stone or brick,

otherwise the walls on the lower

floors on a tall building would be too

thick to be practical. An early

development in this area was Oriel

Chambers in Liverpool. Designed by

local architect Peter Ellis in 1864, the

building was the world's first iron-

framed, glass curtain-walled office

building. It was only 5 floors high.

Elisha Graves Otis

(August 3, 1811 – April 8, 1861)

Skyscraper Building

Early skyscrapers

Further developments led to the

world's first skyscraper, the ten-story

Home Insurance Building in Chicago,

built in 1884–1885. While its height is

not considered very impressive

today, it was at that time. The

architect, Major William Le Baron

Jenney, created a load-bearing

structural frame. In this building, a

steel frame supported the entire

weight of the walls, instead of load-

bearing walls carrying the weight of

the building. This development led to

the "Chicago skeleton" form of

construction.

Skyscraper Building

Early skyscrapers

The Flatiron Building (or Fuller Building,

as it was originally called) is located

at 175 Fifth Avenue in the borough of

Manhattan, New York City and is

considered to be a groundbreaking

skyscraper in 1903. It was designed

by Chicago's Daniel Burnham as a

vertical Renaissance palazzo with

Beaux-Arts styling. Since it employed

a steel skeleton – with the steel

coming from the American Bridge

Company in Pennsylvania – it could

be built to 22 stories (285 feet)

relatively easily, which would have

been difficult using other

construction methods of that time.

Skyscraper Building

Early skyscrapers

The Produce Exchange of 1884 made structural

advances in metal frame design.

Early skyscraper caisson foundations, 1898

Skyscraper Building

Modern skyscrapers

In 1930, The Chrysler Building is an Art

Deco style skyscraper in New York

City, located on the east side of

Manhattan in the Turtle Bay area at

the intersection of 42nd Street and

Lexington Avenue. At 1,046 feet (319

m), the structure was the world's

tallest building for 11 months before it

was surpassed by the Empire State

Building in 1931. It is still the tallest

brick building in the world, albeit with

an internal steel skeleton.

Skyscraper Building

Modern skyscrapers

In 1931, The Empire State Building is a

102-story skyscraper located in

Midtown Manhattan, New York City,

at the intersection of Fifth Avenue

and West 34th Street. It has a roof

height of 1,250 feet (381 meters), and

with its antenna spire included, it

stands a total of 1,454 ft (443.2 m)

high. It stood as the world's tallest

building for 40 years, from its

completion in 1931 until construction

of the World Trade Center's North

Tower was completed in 1972.

Skyscraper Building

Modern skyscrapers

In 1972, The World Trade Center is a

site for various buildings in Lower

Manhattan, New York City, United

States. At the time of their

completion, the original 1 World

Trade Center (the North Tower) and 2

World Trade Center (the South

Tower), known collectively as the

Twin Towers, were the tallest buildings

in the world. To meet the Port

Authority's requirement for 10,000,000

square feet (930,000 m2)) of office

space, the buildings would each

have to be 110 stories tall. It was

developed the tube-frame structural

system used in the twin towers.

Skyscraper Building

Modern skyscrapers

In 1972, The Willis Tower (Sears Tower)

is a 108-story, 1,451-foot (442 m)

skyscraper in Chicago, Illinois.[2] At

the time of its completion in 1973, it

was the tallest building in the world,

surpassing the World Trade Center

towers in New York, and it held this

rank for nearly 25 years. Their team of

architect Bruce Graham and

structural engineer Fazlur Khan

designed the building as nine square

"tubes", each essentially a separate

building, clustered in a 3×3 matrix

forming a square base with 225-foot

(75 m) sides. All nine tubes would rise

up to the 50th floor of the building.

Skyscraper Building

Modern skyscrapers

In 1998, The Petronas Towers are twin

skyscrapers in Kuala Lumpur,

Malaysia. According to the CTBUH's

ranking, they were the tallest

buildings in the world from 1998 to

2004 until surpassed by Taipei 101.

They feature a diamond-faceted

facade consisting of 83,500 square

metres (899,000 sq.ft) of stainless steel

extrusions. In addition, a 33,000-panel

curtain wall cladding system resides

within the towers. Highlighting the

magnificent towers, they are

composed of 55,000 square metres

(590,000 sq.ft) of 20.38-millimetre

(0.802 in) laminated glass to reduce

heat by reflecting harmful UV rays.

Skyscraper Building

Modern skyscrapers

The Taipei 101 (the Taipei World Financial Center), is the first building in the world to

break the half-kilometer mark in height

located in Taipei, Republic of China. The

building ranked officially as the world's tallest

from 2004 until the opening of the Burj Khalifa

in Dubai in 2010. In July 2011, the building was

awarded LEED Platinum certification. Taipei 101 comprises 101 floors above ground and 5

floors underground. The tower is designed to

withstand typhoons and earthquakes. The

design achieves both strength and flexibility

for the tower through the use of high-

performance steel construction. Thirty-six

columns support Taipei 101, including eight

"mega-columns" packed with 10,000 psi (69

MPa) concrete.[13] Every eight floors,

outrigger trusses connect the columns in the

building's core to those on the exterior.

Skyscraper Building

Modern skyscrapers

The Burj Khalifa known as Burj Dubai prior to its inauguration, is a skyscraper in Dubai,

United Arab Emirates, and is the tallest man-made structure in the world, at 829.8 m

(2,722 ft). The tower is designed by Skidmore, Owings and Merrill, which also designed the Willis Tower (formerly the Sears Tower) in Chicago and the new One

World Trade Center in New York City.

The Burj Khalifa uses the bundled tube design. The engineers developed a new

structural system called the buttressed core, which consists of a hexagonal core

reinforced by three buttresses that form the ‘Y' shape. This structural system enables

the building to support itself laterally and keeps it from twisting.

The primary structure is reinforced

concrete. Over 45,000 m3 of concrete

were used to construct the concrete

and steel foundation, which features

192 piles. It used 330,000 m3 of

concrete and 55,000 tons of steel

rebar, and construction took 22 million

man-hours. The remaining structure

above is constructed of lighter steel.

Skyscraper Building

Skyscraper Building

Future skyscrapers

The Burj Mubarak al Kabir is a proposed 250 km2 (62,000-acre) planned urban

area in Subiya, Kuwait, an area just

opposite Kuwait City. The main attraction

of Madinat al-Hareer, the Burj Mubarak al-

Kabir will stand at 1,001 m (3,284 ft) tall.

The development will cost an estimated

94 billion USD.

The Kingdom Tower (Burj al Mamlakah), previously is a

supertall skyscraper proposed

for construction in Jeddah,

Saudi Arabia. The tower was

initially planned to be 1.6-

kilometre (1 mi) high. The

building has been scaled

down from its initial 1.6 km

(about one mile) proposal,

which was never fully

designed, to a height of at

least 1,000 metres (3,280.84

ft).

Skyscraper Building

Future skyscrapers

Name Pinnacle heightYear of first

proposalStructure type Country Town

The Space Elevator 100,000 km (62,000 mi) 1959 Massivespace tether Several undetermined

The Launch loop 80 km (50 mi) 1981 SuspendedMaglev Track U.S. undetermined

Scaled-downSpace

Elevator20 km (12 mi) 2009 Massivespace tether Canada undetermined

X-Seed 4000 4,000 m (13,000 ft) 1995 Arcology Japan Tokyo

Ultima Tower 3,217 m (10,554 ft) 1991 Skyscraper U.S. undetermined

Dubai City Tower 2,400 m (7,900 ft) 2008 SkyscraperUnited Arab

EmiratesDubai

Shimizu Mega-City

Pyramid2,004 m (6,575 ft) 1996 Arcology Japan Tokyo

Millennium Challenge

Tower1,852 m (6,076 ft) 2005 Skyscraper

Kuwait (Possible

location)undetermined

Citygate Ecotower 1,500 m (4,900 ft) 2007 Skyscraper UK London

Bionic Tower 1,228 m (4,029 ft) 1997 Arcology China Hong Kong Hong Kong

Azerbaijan Tower 1,050 m (3,440 ft) 2012 Skyscraper Azerbaijan Baku

Skyscraper Building

Basic design considerations

Good structural design is important in most building design, but particularly for skyscrapers

since even a small chance of catastrophic failure is unacceptable given the high price. This

presents a paradox to civil engineers: the only way to assure a lack of failure is to test for all

modes of failure, in both the laboratory and the real world. But the only way to know of all

modes of failure is to learn from previous failures. Thus, no engineer can be absolutely sure that

a given structure will resist all loadings that could cause failure, but can only have large

enough margins of safety such that a failure is acceptably unlikely. When buildings do fail,

engineers question whether the failure was due to some lack of foresight or due to some

unknowable factor.

Skyscraper Building

Loading and vibration

The load a skyscraper experiences is largely from the force of the building material itself. In

most building designs, the weight of the structure is much larger than the weight of the

material that it will support beyond its own weight. In technical terms, the dead load, the load

of the structure, is larger than the live load, the weight of things in the structure (people,

furniture, vehicles, etc.). As such, the amount of structural material required within the lower

levels of a skyscraper will be much larger than the material required within higher levels. This is

not always visually apparent. The Empire State Building's setbacks are actually a result of the

building code at the time, and were not structurally required. On the other hand John

Hancock Center's shape is uniquely the result of how it supports loads. Vertical supports can

come in several types, among which the most common for skyscrapers can be categorized as

steel frames, concrete cores, tube within tube design, and shear walls.

The wind loading on a skyscraper is also considerable. In fact, the lateral wind load imposed

on super-tall structures is generally the governing factor in the structural design. Wind pressure

increases with height, so for very tall buildings, the loads associated with wind are larger than

dead or live loads.

Other vertical and horizontal loading factors come from varied, unpredictable sources, such

as earthquakes.

Skyscraper Building

Shear walls

A shear wall, in its simplest definition, is a wall where the entire material of the wall is employed

in the resistance of both horizontal and vertical loads. A typical example is a brick or

cinderblock wall. Since the wall material is used to hold the weight, as the wall expands in size,

it must hold considerably more weight. Due to the features of a shear wall, it is acceptable for

small constructions, such as suburban housing or an urban brownstone, to require low material

costs and little maintenance. In this way, shear walls, typically in the form of plywood and

framing, brick, or cinderblock, are used for these structures. For skyscrapers, though, as the size

of the structure increases, so does the size of the supporting wall. Large structures such as

castles and cathedrals inherently addressed these issues due to a large wall being

advantageous (castles), or ingeniously designed around (cathedrals). Since skyscrapers seek

to maximize the floor-space by consolidating structural support, shear walls tend to be used

only in conjunction with other support systems.

Skyscraper Building

Steel frame

The classic concept of a skyscraper is a large steel box with many small boxes inside it. The

genius of the steel frame is its simplicity. By eliminating the inefficient part of a shear wall, the

central portion, and consolidating support members in a much stronger material, steel, a

skyscraper could be built with both horizontal and vertical supports throughout. This method,

though simple, has drawbacks. Chief among these is that as more material must be supported

(as height increases), the distance between supporting members must decrease, which

actually in turn, increases the amount of material that must be supported. This becomes

inefficient and uneconomic for buildings above 40 stories tall as usable floor spaces are

reduced for supporting column and due to more usage of steel.

Skyscraper Building

Tube structural systems

Since 1963, a new structural system of framed tubes appeared. Fazlur Khan and J. Rankine

defined the framed tube structure as "a three dimensional space structure composed of three,

four, or possibly more frames, braced frames, or shear walls, joined at or near their edges to

form a vertical tube-like structural system capable of resisting lateral forces in any direction by

cantilevering from the foundation."[43] Closely spaced interconnected exterior columns form

the tube. Horizontal loads (primarily wind) are supported by the structure as a whole. About

half the exterior surface is available for windows. Framed tubes allow fewer interior columns,

and so create more usable floor space. Where larger openings like garage doors are required,

the tube frame must be interrupted, with transfer girders used to maintain structural integrity.

Tube structures cut down costs, at the same time allow buildings to reach greater heights.

Tube-frame construction was first used in the DeWitt-Chestnut Apartment Building, completed

in Chicago in 1963. It was used soon after for the John Hancock Center and in the

construction of the World Trade Center.

Skyscraper Building

Tube structural systems

The tubular systems are fundamental to tall building design. Most buildings over 40-storeys

constructed since the 1960s now use a tube design derived from Khan’s structural engineering

principles,[3][42] examples including the construction of the World Trade Center, Aon

Centre[disambiguation needed], Petronas Towers, Jin Mao Building, and most other supertall

skyscrapers since the 1960s.[35] The strong influence of tube structure design is also evident in

the construction of the current tallest skyscraper, the Burj Khalifa.

Framed tube

Trussed tube and X-bracing

Bundle tube

Concrete tube structures

Skyscraper Building

AR375 Structural System in Architecture

Dr. Punravee KongboontiamFaculty of Architecture and Environmental DesignMaejo University