VERTICAL BUILDING

STRUCTURES

Prof. Wolfgang Schueller

Shibam, mud-brick-city, Yemen, 16th century,

houses are 5 to 9 stories high

High-rise buildings up to 10 stories or more flourished already in ancient Rome

Stupa Borobudur near Yogyakarta, Java, Indonesia, 9th cent.

San Gimignano, Italy, city of

medieval towers, c. 13th century

The residential towers of Bologna

(Italy) in the 12 th century numbered

80 to 100 at the time, the largest of

which rise to 97 m (319 ft)

Ponttor , Aachen, Germany, 17th-

18th cent., former gate in the city

wall

Aachen Cathedral, Aachen, Germany, 800 - 1880

Aachen Cathedral, Aachen, Germany,

c. 790 - 1884

Palatine Chapel (Octogon),

Aachen Cathedral, c. 790

Glass Chapel (100 ft), Aachen Cathedral, 1414

Cologne Cathedral, 1248 –

1880, towers are 157 m high

The Iron Pagoda (187 ft), Kaifeng, Henan

province, China, 1049 AD (Song Dynasty)

The six minarets of the Blue Mosque (1616),

Istanbul, Turkey

Current tall high-rise building structures

Vertical building structures range from massive building blocks to slender towers. They

may occur as isolated objects or urban mega structures. This geometrical study: from

the single house to the urban building, suggests the formal variations including,

single and cluster houses, free-standing and merging buildings, terraced and

inverted stepped buildings, open and closed shapes,

and so on.

High-rise building shapes range from boxy,

pure shapes (prisms as based on rectangle,

cruciform, pinwheel, etc.) to compound hybrid

forms; the high-rise of the postmodern era

seem to have complete freedom of form-giving.

The building masses may be broken up

vertically and horizontally into interacting

blocks to reduce the scale of the building.

Infinite many possible building shapes depending on urban context, building function,

economy, aesthetics, etc.

Views of Various Buildings

Examples of Terraced

Housing

Atrium Buildings

Sloped Building Structures

European Parliament, Luxemburg

European Parliament, Luxemburg

Visual study of unconventional building structures of the 1960s and 1970s

Some current tall high-rise

building structures

The Formation of Space

Typical Building Sections

Typical Plan Forms

Floor Framing Systems in Concrete

Further floor framing patterns, floor stucture systems, corner framing and core framing

Building Organism:

structure, geometry, function,

elevators, mechanical

systems, zoning, etc.

Plan Forms, Circulation and

Core Location: The vertical

distribution of people along the

cores and horizontal branches to

the respective activity zones that

either consist of closed cellular

aggregates or open layers can

only be suggesgted in this study.

Some of the variables influencing

this flow are: building shape, plan

form and depth, number,

location, and orientation of

core(s); arrangement and access

of activity units.

Circulation Systems for

Apartment Buildings

Movement Systems

The distribution of

mechanical systems to

the various thermal zones

is studied. The flow of the

many systems is

dependent on the

function of the building: in

buldings with fixed

cellular sudivisions a

decentralized branching

may be needed, whereas

in open-office landscapes

a much more centralized

branching of the

mechanical services is

the rule.

Examples of Elevator

Shaft Systems and

Mechanical Floors

Highrise Structure Systems

Possible location of lateral-force resisting structures within the building

The Structure in Plan

Floor Framing Systems

A building structure can be visualized as

consisting of horizontal planes (floor and

roof structures), the supporting vertical

planes (walls, frames, etc), and the

foundations. The horizontal planes tie the

vertical planes together to achieve somewhat of

a box effect, and the foundations make the

transition from the building to the ground

possible.

It is obvious that a slender, tall tower must be a

compact, three-dimensional closed structure where

the entire body acts a unit. On the other hand, a

massive building block only needs some stiff,

stabilizing elements that give lateral support to the rest

of the building.

THE RANGE OF

BUILDING

STRUCTURES

It is obvious that a

slender , tall tower

must be a compact,

three-dimensional

closed structure

where the entire body

acts a unit. On the

other hand, a massive

building block only

needs some stiff,

stabilizing elements

that give lateral

support to the rest of

the building.

Introduction to Load Action

Vertical Force Flow

Lateral Force Flow: Wind

Building Response to Load Action

The development of modern building support structures has its origin in the inventive

spirit of structural engineering and the rapid progress in the engineering sciences

during the 19th century. The birth of the new era of high-rise building construction is

surely reflected by the unbelievable height of the

• Eiffel Tower in Paris, 1889, with 300 m. The exponential shape of the tower is

almost funicular as vertical cantilever with respect to lateral wind pressure and as a

column with respect to weight (i.e. equal stress). The tower conveys an understanding

of equilibrium forms and expresses clearly lateral stability with its wide base similar to

the base of tree trunks.

• With the 15-story Johnson Wax Tower (1950) at Racine, Wisconsin, Frank Lloyd

Wright became the first designer to break away from the traditional skeleton concept

in high-rise construction. He used the tree concept, in his urge toward the organic, by

letting the mushroom-type floor slabs cantilever from the central core, which is deeply

rooted in the ground. Wright freely used the plastic quality of concrete and helped to

even further identify the potential of the material.

Influenced by the newly found possibilities of engineering and the spirit of invention,

the Russian Constructivists experimented in the early 1920s or so with different

building shapes, the deconstruction of the building, in other words by taking a

completely opposite position to the classical tradition of façade architecture.The

constructivist art of modernism surely has influenced designers. Pioneers such as

Antoine Pevsner and Naum Gabo at the early part of this century in Russia, and later

Alexander Calder’s kinetic art and Kenneth Snelson’s tensegrity sculptures.

The birth of the new

era of high-rise building

construction is surely

reflected by the unbelievable

height of the Eiffel Tower in

Paris, 1889, with 300 m. The

exponential shape of the

tower is almost funicular as

vertical cantilever with

respect to lateral wind

pressure and as a column

with respect to weight (i.e.

equal stress). The tower

conveys an understanding of

equilibrium forms and

expresses clearly lateral

stability with its wide base

similar to the base of tree

trunks.

The early development of tall buildings occurred in Chicago from about 1880 to 1900, where

block- and slab-like building forms reached 20 stories.

Then the soaring towers of New York introduced the true skyscraper, the symbol of

American cities.

• Louis Sullivan integrated masterfully abstract stylistic considerations of

tripartite subdivision with the expression of load-bearing in the Guarantee

Building, Buffalo, 1895.

• The Gothic style was applied to the Cathedral of Learning at the University of Pittsburgh

(mid 1930s) to articulate height of the tower through the upward thrust that is the skyscraper.

• The Empire State Building (1250 ft), New York, 1931, Shreve, Lamb, and Harmon - the

building does not express the complexity of the building organism as the modernists do

Notice the further development of the façade and appearance as the effect of

functionalism in the resolution of the wall to a transparent weightless skin or the

deconstruction of the façade takes place.

The early development of modern tall buildings occurred in Chicago from about 1880 to 1900,

where block- and slab-like building forms reached 20 stories.

Then the soaring towers of New York introduced the true skyscraper, the symbol of American

cities.

Louis Sullivan integrated masterfully abstract stylistic considerations of

tripartite subdivision with the expression of load-bearing in the Guarantee

Building, Buffalo, 1895.

Carson Pirie Scott Building,

Chicago, 1899, Louis Sullivan

The Gothic style was applied to the Cathedral of Learning at the University of

Pittsburgh (mid 1930s) to articulate height of the tower through the upward thrust

that is the skyscraper.

Empire State Building (381 m, 1250 ft), New York, 1931, Shreve, Lamb, and Harmon, the

building does not express the complexity of the organism as the modernists do.

Glass skyscraper project, 1920, Mies

van der Rohe

Bauhaus Dessau, Germany, 1926, Gropius

Lever House, New York, 1952,

Gordon Bunshaft/ SOM

Seagram Building, New York,

1958, Mies van der Rohe, Philip

Johnson

gravity flow lateral force flow

Johnson Wax Research Tower (8 stories), Racine, WI, 1944, Frank Lloyd Wright

With the 15-story Johnson Wax Tower

(1950) at Racine, Wisconsin, Frank

Lloyd Wright became the first designer

to break away from the traditional

skeleton concept in high-rise

construction. He used the tree

concept, in his urge toward the organic,

by letting the mushroom-type floor slabs

cantilever from the central core, which

is deeply rooted in the ground. Wright

freely used the plastic quality of

concrete and helped to even further

identify the potential of the material.

Notice the further development of

the façade and appearance as the

effect of functionalism in the resolution of the

wall to a transparent weightless skin or the

deconstruction of the façade takes place.

Engineering College, Ningbo

Institute of Technology, Zhejiang

University, Ningbo, 2002,

Qingyun Ma

Library, Ningbo Institute of Technology, Zhejiang University, Ningbo, 2002, Qingyun Ma

Administration Building, Ningbo Institute of Technology, Zhejiang

University, Ningbo, 2002, Qingyun Ma

University Hotel, Ningbo Institute of Technology, Zhejiang University

Tour Lilleurope (115m), Lille, France, 1995, Claude Vasconi

Building complex in

Amsterdam

Lloyd’s Registry, London, 2000,

Richard Rogers, Anthony Hunt

Dormitory of Nanjing University,

Zhang Lei Arch., Nanjing University,

Research Center o0f Architecture

Tod’s Omotesanto Building,

Tokyo, Japan, 1997, Toyo Ito,

network of concrete trees

Audi Forum Tokyo –t he Iceberg, 2006,

Benjamin Warner

The transition of the high-rise building

to the base and its interaction with the urban

scale has become has become an important design

consideration.

The transition of

building to base

ING Group Headquarters,

Amsterdam, 2002, Meyer en

Van Schooten Arch

NordDeutsche Landesbank am

Friedrichswall, Hannover, 2002,

Behnisch

4/15/2016 84

Real Life

Exchange House, London, 1990, SOM; located directly over the British Rail train tracks north of the

historic train sheds that were renovated as part of the overall development, the 10-story office block

supported on an expressed structural frame spans the tracks in the manner of a bridge, with a parabolic

arch the basis of the overall structural engineering design.

Influenced by the newly found possibilities of

engineering and the spirit of invention, the Russian

Constructivists experimented in the early 1920s or so

with different building shapes, the deconstruction of

the building, in other words by taking a completely

opposite position to the classical tradition of façade

architecture. The following slides reflect some of that

spirit: The constructivist art of modernism surely has

influenced designers. Pioneers such as Antoine

Pevsner and Naum Gabo at the early part of this

century in Russia, and later Alexander Calder’s

kinetic art and Kenneth Snelson’s tensegrity

sculptures.

“Monument to the Third

International,” model designed by

Vladimir Tatlin, 1920, experiments

with structure, Russian

Constructivism

Shabolovka tower, Vladimir Shukhov, 1922, Moscow

Experiments with structure,

Russian Constructivism

Experiments with structure, Russian Constructivism

Early 1960s, glass sculptures of Harry

Saeger

Early 1960s, glass sculptures

of Harry Saeger

Ribat, 1979, wood sculpture

Picasso sculpture, Chicago,

1967

Tree of Bowls, Jean (Hans) Arp,

Foundation Beyeler,

Riehen/Basle, Switzerland, 1960

Kenneth Snelson, Needle Tower, 1968,

Hirshorn Museum, Washington; this 60-ft

high (18 m) tower explores the spatial

interaction of tension and compression.

A network of continuous cables is

prestressed into shape by discontinuous

compression struts which never touch

each other. Buckminster Fuller explained

tensegrity as tensile integrity, as

islands of compression in a sea of

tension

The primary load-bearing structure of

a building is subdivided into the

gravity structure and the lateral-

force resisting structure which

resists wind and earthquakes and

provides lateral stability to the

building.

A building structure can be visualized as consisting of horizontal planes (floor and roof

structures), the supporting vertical planes (walls, frames, etc), and the foundations. The

horizontal planes tie the vertical planes together to achieve somewhat of a box effect, and the

foundations make the transition from the building to the ground possible.

Tower, steel/concrete frame, using Etabs

Turning Torso (Lateral-

force resisting tower), (25

stories), Malmö, Sweden,

2005, Santiago Calatrava,

based in form on “turning

torso”

Gravity structure: Rosenthal Center for

Contemporary Art, Cincinnati, 2004, Zaha

Hadid

The strength and stiffness of a

building is very much related to the

type and arrangement of the

vertical structural elements, as

is suggested in this study of

structure placement in plan. The

density and interaction or

continuity, of the elements, together

with the degree of symmetry,

indicate the degree of compactness

of the structure.

However, not only the

horizontal building cross-

section where the location of

the structure is defined, but

also the nature of the vertical

structures in the vertical

section (i.e. elevation of

structure) must be considered

as is demonstrated in the

drawing for planar structures.

Introduction to load action

The vertical force flow is

investigated in this drawing.

Notice that the type and pattern

of force flow depend on the

arrangement of the vertical

structural planes. The path of the

force flow may be continuous

along the columns or may be

suddenly interrupted and

transferred horizontally to

another vertical line. The

transmission of the loads may be

short and direct, or long and

indirect with a detour as for a

suspension building. When

columns are inclined, gravity

will cause directly lateral

thrust, keeping in mind,

continuous rectangular frame

action will cause indirect

lateral action.

Some considerations related to wind action are studied in this drawing indicating that

wind loads are not simply uniform pressure values as given by codes.

The building response to lateral load action is investigated in this drawing. The

horizontal forces are transmitted along the floor/roof diaphragms, which act as deep

flat horizontal beams, to the vertical lateral-force resisting structures which in turn

respond as vertical , flexural or shear cantilevers.

In this study of the

building response

to force action, the

increase of force

flow towards the

base is

convincingly

expressed by the

density of the

stress trajectories

and the truss

analogy.

This drawing shows a high-rise building structure under gravity and

lateral load action modeled as an engineering line diagram.

Introduction to Response

of Building to Load Action

High-rise structures range from pure structure systems, such as skeleton and

wall construction, and systems requiring transfer structures, to composite

systems and mega-structures.

As the building increases in height, or buildings become slenderer, different

structure systems are needed for reasons of efficiency, i.e. a particular structure

system is applicable within certain height limits, that is as the scale changes

different structure systems are required.

The effect of scale is known from nature, where animal skeletons become

much bulkier with increase of size as reflected by the change from the tiny ant

to the delicate gazelle and finally to the massive elephant. The impact of

scale on structure and form is apparent from nature not only with respect to

animals but also plants. For instance, the slenderness height-to-diameter of

the wheat stalk is around 500, while it decreases to 133 for bamboo and to

about 36 for a giant redwood tree, clearly illustrating again that proportions are

not constant but change. We may conclude that structure proportions in

nature are derived from behavioral considerations and cannot remain

constant. Thus the dimensions are not in linear relationship to each other; the

weight increases much faster than the corresponding cross-sectional

area.

This phenomenon of scale is taken into account by the various structure

members and systems as well as by the building structure types as related to

the horizontal span, and vertical span or height. With increase of span or

height, material, member proportions, member structure, and structure

layout must be altered and optimized to achieve higher strength and

stiffness with less weight.

For high-rise steel buildings the efficiency of a particular structure system is

measured as the quantity of material used that is the weight per square foot or

the total building structure weight divided by the total square footage of the

gross floor area.

The effect of the scale is clearly reflected by the change of weight for a

10-story braced frame structure from 6 psf (0.3 kPa or kN/m2)) to 29 psf (1.4

kPa) for a 100-story tubular structure!

The discussion above refers only to ordinary buildings; special building

configuration (in plan and elevation) and special load transfer conditions

obviously have their unique solution and cannot be organized according to

general rules.

The efficiency of a concrete structure is evaluated to a

great extent in terms of process of construction, in additions to the

quantities of materials used that is roughly between 0.5 ft3/ft2 (0.15

m3/m2) to 1.0 ft3/ft2 (0.30 m3/m2) concrete, and reinforcing steel of 2 lb/ft2

(96 N/m2 = 9.67 kgf/m2) to 4 lb/ft2 (192 N/m2 = 19.53 kgf/m2), in contrast

to steel, which considers only the quantity of material used.

Basic design considerations

As already mentioned previously, every building consists of the load-bearing

structure and the non-load-bearing portion. The main load bearing structure,

in turn, is subdivided into:

Gravity structure consisting of floor/roof framing, slabs, trusses,

columns, walls, foundations

Lateral force-resisting structure consisting of walls, frames,

trusses, diaphragms, foundations

Support structures, in general, may be classified as,

Horizontal-span structure systems:

floor and roof structure

enclosure structures

Vertical building structure systems:

walls, frames cores, etc.

tall buildings

VERTICAL BUILDING STRUCTURE SYSTEMS 1

EXAMPLES OF VERTICAL BUILDING STRUCTURES

Vertical building

structure systems ,

organized according to

efficiency

The functioning of the building

The presentation of building structures is organized as follows:

STRUCTURE SYSTEMS

A NEW GENERATION OF BUILDING STRUCTURES

THE NEXT GENERATION OF SKYSCRAPERS

GREEN HIGHRISE BUILDINGS

SUPERTALL (SLENDER) BUILDINGS

STRUCTURE SYSTEMS

• Bearing wall structures (up to approximately 28 stories)

• Core structures (and bridge structures)

• Suspension buildings

• Skeleton structures and flat slab building structures

Rigid frame (up to ≈ 30 stories)

• Braced frame structures: frame with shear wall/core (45 stories)

Staggered wall-beam structures (up to ≈ 40 stories)

Frame with shear, band and outrigger trusses (up to ≈ 60 stories)

• Partial tubular systems (up to ≈ 65 stories)

Exterior framed tubular (up to ≈ 90 stories)

Bundled framed tubes (up to ≈ 110 stories)

Exterior diagonalized tubes (up to ≈ 115 stories)

• Mega-structures

Hybrid structures

The bearing wall was the primary support structure for high-rise

buildings before the steel skeleton and the curtain wall were introduced in the

1880s in Chicago. The traditional tall masonry buildings were massive

gravity structures where the walls were perceived to act independently; their

action was not seen as part of the entire three-dimensional building body. It

was not until after World War II that engineered thin-walled masonry

construction was introduced in Europe.

Bearing wall construction is used mostly for building types that require

frequent subdivision of space such as for residential application. Bearing

wall buildings of 15 stories or more in brick, concrete block, precast large-

panel concrete, or cast-in-place reinforced concrete are commonplace

today; they have been built up to the 26-story range.

BEARING WALL STRUCTURES

16-story Monadnock Building,

Chicago, 1891, John Wellborn

Root, clear expression of

structure (no decoration)

Plan forms range from slab-type buildings and towers of various shapes to any

combination. The wall arrangements can take many different forms, such as the cross-

wall-, long-wall-, double cross-wall-,tubular-, cellular-, and radial systems.

The walls may be continuous or perforated to various degree, as is suggested in the

study of the effect of lateral load action upon walls with openings.

Study of gravity force flow along walls:The nature of gravity force flow can be visualized as the

flow of water which is distributed when an object is submerged in the uniform current thereby

displacing the flow lines. The resulting flow net depends on the type of opening in the wall and

support conditions. The degree of disturbance, that is the crowding of the stream lines, indicates

the increased speed or the corresponding intensity of load action

High-rise cantilever walls

Perforated Concrete Wall

18-story Nederlandse

Gasunie, Groningen, 1994,

Alberts + Van Huut Arch., is

organically shaped to

reflect the constant

movement under the

change of sun and

weather. The slender

building, 1:6.7, consists of

load bearing concrete walls

anchored front to back by

nearly ½ m thick diaphragm

walls. The 60-m glass wall

in front, which appears

almost like a waterfall, is

carried by an enormous

steel space frame covering

the atrium space.

Dormitory of Nanjing University,

Zhang Lei Arch., Nanjing

University, Research Center of

Architecture

Neuer Zollhof, Duesseldorf, Germany, 1998, Frank

O. Gehry, looks like an unstable collage, they are

solid concrete walls for the middle portion of the

building group, The walls of the center building

have a surface whose shape is much like that of

folds of hanging fabric, where the undulating wall

is clad in polished stainless steel

Unite d’Habitation, Marseille,

France, 1952, Le Corbusier, is

450 ft (137 m) long, 80 ft (24 m)

wide and 184 ft (56 m) high and

the cross walls are spaced at

circa 4 m.

Typical cross shear wall structure

The behavior of ordinary

cross shear walls

Typical long-wall structure

Zollverein School of Management & Design, Essen, 2006, SANAA : Kazuyo Sejima +

Ryue Nishizawa, SAPS / Sasaki, Tokio, B+G Ingenieure / Bollinger und Grohmann

Apartment

building,

Heerlen,

Netherlands

WALDEN 7, 1974. Sant Just Desvern. Barcelona, Ricardo Bofill. The building is a vertical labyrinth

consisting of seven interior patios linked on all levels by vertical and horizontal circulation routes. The

dwellings, the combination of square 30 m2 modules, come in different sizes, ranging from the single-

module studio to the four-module apartment, either on one floor or duplex.

Visual study of the structure of Walden 7

LA MURALLA ROJA, 1973. Calpe, province of Alicante, Spain, Ricardo Bofill

Visual study of LA MURALLA ROJA

Visual study of LA

MURALLA ROJA

Black castle,

Spain, Ricardo

Bofill

Visual study of Stufendomino Lyngberg, Bonn- Bad Godesberg, Wetzel Wohnbau, 1975

The fractal space of Moshe Safdie’s Habitat 67 in Montreal, Canada, consists of load bearing precast concrete

boxes which were stacked 12 stories high and are tied together by post-tensioning. The vertical elevator shafts

and stair cores together with elevated horizontal streets give lateral support in frame action to the asymmetrical

assembly.

Visual study of box-type wall arrangements

Ramot Housing Complex, 1970s,The

Cube and the Dodecahedron in My

Polyhedric Architecture, Zvi Hecker

Sky Village (380 ft), Rødovre, Copenhagen, 2011, MVRDV

Sky Village—as the mixed-use building is being called—steps out in more than one direction.

Designed by Rotterdam-based MVRDV and its Danish codesigners, ADEPT, the 380-foot-tall

“stacked neighborhood” features a combination of apartments, offices, retail, and parking.

The basic design starts with a square grid of 36 units, or pixels, each two stories tall and

measuring 251⁄2 feet wide by 251⁄2 feet long, a dimension arrived at for its flexibility for use

as a suitable parking grid, housing unit, and office type. The four central pixels make up the

core. Surrounding pixels are removed and stacked on top of each other in various

configurations, though no single floor comprises all 36 pixels. The building gets “fattest”

about a third of the way up, where floors contain up to 26 pixels. “We’re very fond of

Legos and use them in the office for conceptual designs,” says Anders Peter Galsgaard, one

of the Copenhagen-based engineers. “We try to build the same way.”

Galsgaard also likens the structure to a Christmas tree, with a very stiff base, in

this case consisting of two levels of underground parking, and a main trunk, the

cast-in-place concrete core made up of elevators, stairs, and shafts. The pixels,

which have a column at each of the corners and diagonal bracing on two

sides, will hang from the core from steel trusses rather than cantilever in the

traditional sense. According to Galsgaard, “Hanging the pixels this way creates a

lot of compression in the core, so even under very high wind loads there is very

little tension, which allows us to use steel more efficiently.”

CORE STRUCTURES

Many multi-core buildings with their exposed service shafts have been

influenced by the thinking of the Metabolists in Japan of the 1960s, who

clearly separated the vertical circulation along cores and the served spaces.

Their urban clusters consisted of vertical service towers linked by multilevel

bridges, which in turn contained the cellular subdivisions.

Many multi-core buildings with their exposed service shafts

have been influenced by the thinking of the Metabolists of the

1960s, who clearly separated the vertical circulation along

cores and the served spaces. Their urban clusters consisted of

vertical service towers linked by multilevel bridges, which in

turn contained the cellular subdivisions. The linear bearing wall

structure works quite well for residential buildings where

functions are fixed and energy supply can be easily distributed

vertically. In contrast, office and commercial buildings require

maximum flexibility in layout, calling for large open spaces

subdivided by movable partitions. Here, the vertical circulation

and the distribution of other services must be gathered and

contained in shafts and then channeled horizontally at every

floor level. These vertical cores may also act as lateral

stabilizers for the building.

Visual study of core structures

The linear bearing wall structure works quite well for residential buildings where functions are

fixed and energy supply can be easily distributed vertically. In contrast, office and commercial

buildings require maximum flexibility in layout, calling for large open spaces subdivided by

movable partitions. Here, the vertical circulation and the distribution of other services must be

gathered and contained in shafts and then channeled horizontally at every floor level. These

vertical cores may also act as lateral stabilizers for the building.

Joint Core System, Arata Isozaki, 1960

Study of central core structures

There is an unlimited variety

of possibilities related to the

shape, number, arrangement,

and location of cores. They

range from single-core

structures (e.g. core with

cantilevered floor framing) to

multiple core structures.

A.N. Richards Medical Research Laboratory, Philadelphia, Louis Kahn

A.N. Richards Medical

Research Laboratory,

Philadelphia, Louis Kahn

SHIZUOKA PRESS & BROADCASTING CENTER,Tôkyô, 1967, Kenzo Tange

Torre de Collserola, Norman Foster, 1992, guyed mast

Knight’s of Colombus Building (23

stories), New Haven, 1970, Kevin Roche

Marina Towers (179 m, 62 stories), Chicago, 1964, Bertrand Goldberg Marina City. The first 18 stories of

each tower consist of continuously rising circular slabs for parking. The remaining 62 stories consist of

pie-shaped apartments with cantilevered balconies which give the towers a scalloped form. (Chicago,

Illinois)

Kisho Kurokawa, Nakagin Capsule

Tower, Tokyo, Japan, 1972, The 14-

story high Tower has 140 capsules

stacked at angles around a central

core. Kurokawa developed the

technology to install the capsule

units into the concrete core with only

4 high-tension bolts, as well as

making the units detachable and

replaceable.

Federal Reserve Building, Boston, 1972, Stubbins Arch, Le Messurier Struct. Eng., 3-story

transfer trusses carry 30 floors to the end cores

OCBC Center (197.7 m (649 ft), Singapore, 1976, I.M. Pei, Arup,,

concrete mega-frame

Torre Caja Madrid, 250 m (820 ft) and

45 floors, 2008, Foster, Halvarson and

Partners

Chicago firm collaborates to design Spain's tallest building

The Torre Repsol high-rise building was designed by the architectural firm Foster and Partners to be the

new corporate headquarters for Repsol YPF S.A., Spain's largest oil company. The tower—located in

Madrid on the former training grounds of the Real Madrid soccer team—is part of a new business park

called Cuatro Torres, which includes three other new office towers. At 250 meters (820 feet), Torre Repsol

will be the tallest of the four new buildings, as well as the tallest in Spain.

Halvorson and Partners of Chicago collaborated with Foster and Partners to design a unique and iconic

building, which would be used to consolidate the oil company's many smaller offices into one central

location. Ultimately, the tower's design would include five parking levels below grade and 34 office floors

(a total of approximately 110 square meters) divided into three distinct office blocks of 11, 12, and 11

floors. Each office block is supported on a set of two-story steel trusses that span between two reinforced

concrete cores.

The trusses transfer all of the tower's gravity loads to the two cores, which are the only vertical load-

carrying elements that extend to the foundation. The trusses also link the cores together, and in essence,

behave as a large moment-frame to resist east-west lateral forces. The typical office floor plate

cantilevers to the north and south of the cores with only two exterior columns on the north and south

faces.

Buildings in Madrid are typically founded on drilled piers that bear on a stiff clay layer called Tosca. At the

Cuatro Torres site, the Tosca clay is approximately 20 meters below grade, and it was presumed that a

mat foundation supported on drilled piers would be the appropriate foundation.

Concrete cores and transfer trusses

The two reinforced concrete cores, located on the east and west sides of the building, are the only vertical load-carrying elements of

the tower that extend down to the mat foundation; achieving one of the owner's objectives—a column-free lobby. The eight gravity-

load columns on the typical office floor plate are transferred to the cores by three sets of two-story-deep trusses. In plan, each core

measures 22 meters in the north-south direction and 10 meters in the east-west direction; with wall thickness of 1,200 millimeters at

the base to 400 millimeters at the top.

North-south lateral loads are resisted by pure cantilever action of two cores, and since the gravity load for the entire building is

carried by the cores, there is no uplift or tensions in the core walls, even with an aspect ratio of 11 to 1.

For east-west lateral loads, the cores are too narrow to provide adequate strength and stiffness as pure cantilevers, and the transfer

trusses are used to link the two cores together, such that the system behaves like a large moment-frame to resist lateral forces.

At each of the three truss levels, the system of trusses consists of the following: two primary trusses that span east-west—32 meters

between the cores; and two secondary trusses that cantilever 10 meters north and south from the primary trusses and transfer the

eight gravity columns back to the primary trusses. Ideally, the primary trusses would be simple span between the cores; however,

since the primary trusses also interact with the cores to resist lateral loads, the top chord of the truss would need to be connected to

the core. Connecting the top chords of the truss to the core walls would induce negative bending moments in the truss under gravity

loads, resulting in top-chord tensions at the connection to the core. To minimize the gravity-load negative moments, the top-chord

connection of the primary trusses to the core has been detailed to allow horizontal movement; this connection was not fully t ightened

until the full structural dead load had been applied to the truss. Therefore, in the permanent condition, top-chord tensions only result

from live loads and east-west lateral loads.

The connection of the primary trusses to the cores is one of the most critical in the building. Transmitting the large gravity and lateral

loads to the cores is accomplished with a robust and positive connection of the truss chords to an embedded, built-up steel column

within each core (four total). During erection, the tension force that would develop in the bottom chord of the primary truss actually

resolves itself as a horizontal thrust against the cores, since the bending stiffness of the cores is larger than the axial stiffness of the

truss chord. The thrust on the cores caused complexity with the diaphragm-to-core connection details of the floors above and below

the truss levels. To eliminate this thrust, post-tensioning tendons are provided along the bottom chord of the primary truss and

anchored to the embedded column in the cores. In addition to minimizing the axial thrust, the post-tensioning provides a level of

redundancy for the critical truss to core connection.

At each level where the truss top and bottom chords attach to the core, a 1,900-millimeter-thick slab is provided within the core. The

thick slabs provide a means of engaging the full cross-section of the core to resist the truss chord forces. The 1,900-millimeter slabs

are reinforced with both mild reinforcement and post-tensioning tendons in two directions.

Herbert F. Johnson Museum of Art, Cornell University, 1973, I. M. Pei, constructivist sculpture

Herbert F. Johnson Museum of Art, Cornell University, 1973, I. M. Pei, constructivist sculpture

STC Building, New Delhi,

1989, Raj Rewal

Hypobank (21 stories), Munich, Germany, 1981, Walter and Bea Betz

Triangle building,

Friedrichstr/ Mauerstr.

Berlin, 1996, Josef Paul

Kleihues

Sendai Mediatheque, Kasuga-machi, Aoba-ku,

Sendai-shi, Japan, Toyo Ito + Mutsuro Sasaki,

2001; the transparent facade allows the

revelation of diverse activities that occur within

the building. Along this main facade the six 15.75-

inch-thin floor slabs seem to be floating within the

space connected only by the 13 vertical tube

steel lattice columns that rise up from ground

floor to roof, similar to the trunks of trees of a

forest. The tubes are both structure and vector for

light and all of the utilities, networks and systems

that allow for technological communication and

vertical mobility, including elevators and

stairs. Each vertical shaft varies in diameter and

is independent of the facade, allowing for a free

form plan which varies from floor to floor.

Visual study of Urban Megastructure and Bridge Structures

Yamanashi Communications

Center, Kofu, Japan, 1967,

Kenzo Tange

University Clinc (Klinikum), Aachen, Germany, 1981, Weber + Brand

University Clinc (Klinikum), Aachen,

Germany, 1981, Weber + Brand

Visual study of bridge buildings

The Hong Kong Club and Office Building, Hong Kong, 1983, Harry Seidler, 112-ft (34 m)

curved prestressed concrete girders are shaped according to the intensity of force flow

and carry the loads to four huge S-shaped corner columns

The Hong Kong Club and Office Building, Hong Kong, 1983, Harry Seidler, 112-ft (34 m)

curved prestressed concrete girders are shaped according to the intensity of force flow

and carry the loads to four huge S-shaped corner columns

SUSPENSION BUILDINGS

The application of the suspension principle to high-rise construction rather than

roof structures is essentially a phenomenon of the late 1950s and 1960s. The

structuralists of this period discovered a wealth of new support structure systems

in the search to minimize the material and to express lightness allowing no visual

obstruction with heavy structural members. The fact that hanging the floors on

cables required only about one-sixth of the material compared to columns

in compression, provided a new challenge to designers.

Tree-like buildings with a large central tower, from which giant arms are

cantilevered at the top or intermediate levels, to support tensile columns, are

quite common today. The typical suspension systems use the

• rigid core principle (single or multiple cores with outriggers or beams, mega-

frames, tree-like frames, etc.),

• guyed mast principle,

• tensegrity or spacenet principle.

Visual study of suspension structures

Westcoast Transmission Tower, Vancouver, Canada, 1969

Hospital tower of the University of Cologne, Germany, Leonard Struct. Eng.

Lille Europe Tower (115 m), Lille, France, 1995, Claude Vasconi, where the floors are

suspended from a huge cross-beam on top which, in turn, is supported by the end cores

Standard Bank Centre (35 stories),

Johannesburg, South Africa, 1970, Hentrich-

Petschnigg

The 22-story, 100-m high, BMW Building in Munich,

Germany (1972, Karl Schwanzer) consists of four suspended

cylinders. Here, four central prestressed suspended huge

concrete hangers are supported by a post - tensioned bracket

cross at the top that cantilevers from the concrete core.

Secondary perimeter columns are carried in tension or

compression by story-high radial cantilevers at the

mechanical floor level. Cast aluminum cladding is used as

skin.

Visual study of the Narcon

Building, Hannover, 1984,

Visual study of the Narcon

Building, Hannover, 1984

Olivetti Building (5 floors), Florence, Italy, 1973, Alberto Galardi

Old Federal Reserve Bank Building,

Minneapolis, 1973, Gunnar Birkerts, 273-ft

(83 m) span truss at top

Singapore Tower, 2007 - ,

Rem Koolhaas (OMA)

Lookout Tower Killesberg (40 m), Stuttgart, 2001, Schlaich

SKELETON STRUCTURES,

FLAT SLAB BUILDING STRUCTURES

When William Jenney in the 10-story Home Insurance Building in Chicago

(1885) used iron framing for the first time as the sole support structure

carrying the masonry façade walls, the all-skeleton construction was born.

The tradition of the Chicago Frame was revived after World War II when the

skeleton again became a central theme of the modern movement in its search

for merging technology and architecture. A typical expression of this era are

Mies Van der Rohe’s buildings, which symbolize with their simplicity of

expression the new spirit of structure and glass.

Visual study of skeleton structures

The skeleton structure in plan

Typical skeleton structures in elevation

Skeleton steel connections

Some Typical Curtain Walls

Various Colunmn

Exposures

Curtain Walls

Frame behavior

3 Sp @ 20' = 60'1

5 S

p @

12

' =

18

0'

7 S

p @

25

ft

= 1

75

ft

18

0/2

= 9

0'

2(1

80

)/3

= 1

20

'

Analysis of frames

Lake Shore Drive Apts, Chicago, Ludwig Mies van der

Rohe, at Chicago, 1948 to 1951

The drawing of Mies van der Rohe’s 52-story, 212-m IBM Tower in Chicago (1973)

expresses the structural action and organization of the steel frame; the building is

controlled by the grid of 9 x 12 m; the grid seems almost to subdue the structural action

Beijing Jian Wai SOHO, Beijing, Riken Yamamoto, 2004

Beijing Jian Wai SOHO, Beijing, Riken

Yamamoto & Field Shop

New architecture next to

Tsinghua University, 2006

National Permanent Building (1977),

Washington, Hartman-Cox

Lloyd’s of London (20 floors), 1986,

Richard Rogers, Arup

Simmons Hall dormitory, MIT, (2002), Steven Holl, Guy Nordensen

Simmons Dorm, MIT, Boston, 2002, Steven Holl. The undergraduate residence is envisioned with

the concept of "porosity." It is a vertical slice of city, 10 stories tall and 382' long, providing a 125 seat theater, a

night café, and street level dining. The "sponge" concept transforms the building via a series of programmatic and

bio-technical functions. The building has five large openings corresponding to main entrances, view corridors, and

outdoor activity terraces. Large, dynamic openings are the lungs, bringing natural light down and moving air up.

Each of the dormitory's single rooms has nine operable windows. An 18" wall depth shades out the summer sun

while allowing the low angled winter sun to help heat the building. At night, light from these windows is rhythmic

and magical.

178 Mirador, Madrid, Spain

2004, MVRDV

Ching Fu Group Headquarters,

Kaohsiung, Taiwan, 2007, Richard

Rogers

The Colonnade (28 stories),

Singapore, 2001, Paul Rudolph

Wisma Dharmala Sakti (30 stories), Jakarta,

Indonesia, Paul Rudolph – adopted local

character of Indonesian architecture

Lippo Center (44 floors, 172

m), Hong kong, 1988, Paul

Rudolph, he Lippo Centre is

popularly referred to as the

"Koala Buildings" because the

shapes look like koala bears

climbing a tree trunk.

The Netherlands Architectural

Institute, Rotterdam, 1993, Jo

Coenen Arch.: The building

complex is divided into several

sections suggesting its

continuation into urban

context. The concrete skeleton

dominates the image

supplemented by steel and

glass. The main glazed

structure appears to be

suspended, and allows the

concrete load-bearing structure

behind to be seen. The high,

free-standing support pillars

and the wide cantilevered roof

appear more in a symbolic

manner rather as support

systems. The building complex

clearly articulates its presence

to the context.

Visual study of the skeleton as assembly: the various systems can only suggest the

infinite variation in which the linear beam and column elements can be formed and

related to one another

Flat slab building structures:

from a behavioral point of view

flat slabs are highly complex

structures. The intricacy of the

force flow along an isotropic

plate in response to uniform

gravity action is reflected by

the principal moment contours

BRACED FRAME STRUCTURES

The most common construction method is, to resist lateral force action through

bracing; it is applied to all types of buildings ranging from low-rise structures to

skyscrapers. At a certain height, depending on the building proportions and the

density of frame layout, the rigid frame becomes too mushy and may be

uneconomical so that it must be stiffened.

Typical Braced

Frame Structure

The difference in stiffness between frame and braced frame

Shear wall - frame interaction

Concrete Frame-Shear Wall Interaction: self-weight case

Example Rigid Frame Shear Wall interaction

Example hinged steel frame braced by concrete shear wall a

Gravity action

Multi-bay concrete shear wall steel frame building: under gravity and lateral load action

Bracing systems for tall buildings

Visual study of braced frame structure

Visual study of braced frame structure

Housing, Isle of Dogs, London, Docklands, UK, 1989, Campbell etc.

Office Building, Central Beheer, Apeldorn, Holland, 1987, Herman Herzberger

Visual study of shear wall/ core – frame interaction systems in plan: typical structures

are shown, in some cases the core is the stiffest element and resists nearly all the

lateral loads, in other building the resistance to lateral force action is shared.

Example of core – frame structure

Visual study of floor framing systems

Richard Daley Center, Chicago,

1965, C.F. Murphy

Daley Center Building; this 31-story steel frame building is constructed in Cor-Ten

steel. It is a larger scale frame consisting of 89-ft. wide bays, the horizontal beams

being deep I-beams with web stiffeners. The steel sculpture in the plaza in front of

the building is by Picasso. (Chicago, Illinois)

Inland Steel Building, Chicago, 1957, Walter Netsch + Bruce Graham (SOM)

First National Bank Building (844 ft, 60 stories). Chicago, 1969, C. F. Murphy, This 60-

story building completed in 1969 has a concrete frame with a curved taper giving the

structure a broad base. (Chicago, Illinois) First National Bank Building. View of the

half-width of the base of the building. At the right is the center line of the building,

and this line is vertical (also seen to the right in GoddenF22). The sloping members

to the left are the main outside columns which form the continuous taper of the

building width. (Chicago, Illinois)

Transamerica Pyramid,

San Francisco, 1972,

William L. Pereira

AT&T, New York,

Johnson/Burgee

Staggered wall-beam buildings: story-high wall beams span the full width of the building on

alternate floors of a given bay and are supported by columns along the exterior walls; there

are no interior columns. One can visualize the apartment units to be contained between the

wall-beams and to be vertically stacked to resemble masonry bond patterns.

Staggered truss examples

STEEL PLATE SHEAR

WALLS

Steel plate shear walls

Bridge Structures

Visual study of façade trussing: lateral

bracing of buildings need not to be

restricted to internal cores, shear walls,

etc, it may also be expressed on the

façade, serving aesthetic as well

structural functions

Visual study of façade

trussing

Century Tower, Tokyo, 1991, Norman Foster

Central Plaza, Kuala Lumpur,

Malaysia, 1996, Ken Yeang

NTV Nittele Tower, Tokyo, 2003,

Richard Rogers

Turmhaus am Kant-Dreieck mit

Wetterfahne aus Blech, Berlin,

Josef Paul Kleinhues, 1994

Capita Centre , Harry Seidler &

Associates , 1989, Sydney, 34 levels

above ground (including a 3 storey

lobby), 2 levels of basement ,

rectangular reinforced concrete core,

external columns, lateral bracing truss

- material composite structural

steel/concrete

The external truss runs vertically over

the East facade and consists of three

"chords" which read as columns; the

top, middle and bottom, at 12 m

spacings. In between these run

diagonal webs which act as lateral

bracing.

The members are of similar

construction to the columns, being

made up of a welded steel box section

that is rigidly bolt fixed to the steel

floor structure and then encased in

concrete.

Poly International Plaza (36

stories, 165 m), Guangzhou, China,

2007, SOM

Linked Hybrid Housing, Beijing, Steven Holl, 2009

SLICED POROSITY BLOCK, Chengdu,

China, 2012, Steven Holl Architects

The Leadenhall Building, London, 2010,

Rogers Stirk Harbour + Partners, Arup

Proposal for 75-story tower

next to MoMA, New York,

Jean Nouvel

High Line (HL) 23, 14

story, New York, 2009,

Neil M. Denari, Desimone

Consulting Engineers

Denari, like OMA, was faced with a narrow Manhattan lot, which was further

constrained by the presence of the High Line—a 22-block-long former railway

that rises almost 20 feet above grade—immediately adjacent to it. But unlike

OMA’s tower a few blocks east, which is completely (and surprisingly) as-of-

right, Denari’s building— his first ground-up design—required a number of

waivers. “There were a lot of restrictions for this site, but the developer was not

interested in conforming to the building code,” Denari admits. “He really wanted

to push boundaries.” Fortunately for both the architect and the developer, the

city was behind the project, particularly because of its relation to the High Line,

which is currently being transformed by Diller Scofidio + Renfro and Field

Operations from its disused state into a nearly 7-acre, elevated urban park.

Denari’s project also takes a much different structural approach than 23 East

22nd Street. “Because the building is wider at the top than at the bottom,

there is a natural instability,” explains Stephen DeSimone, president of

DeSimone Consulting Engineers, who is working with Denari. “By using

steel—which is a much lighter building material—you automatically

reduce the effect of the building wanting to topple over.” So, unlike 23 East

22nd Street, which can be described as a brute-force solution with its thick

concrete walls, HL23 is made up of slender structural members, including

canted steel columns (at a maximum 24-degree angle and located mostly along

the long, steel-clad eastern facade) and diagonal bracing (composed of 8-inch

pipes and forming a tripartite composition on the glazed north and south

elevations).

The building reaches overall stability only

upon completion of construction.

Throughout the construction process, guy-

wires provide supplemental bracing. They

will stay in place until the concrete slabs are

poured. Because of the small building footprint,

concrete is not used in the elevator core.

Instead, a steel plate acts as a sheer wall to

take horizontal and twisting loads—the first time

such an assembly has been used in a

residential building in New York City, according

to the engineers.

The structure is also integral to the envelope,

and was designed at the same time, with

facade consultant Front, to avoid any “reverse

engineering,” as Denari puts it. The sloping

east facade, which cantilevers a total of 14

feet 6 inches over the High Line (it is set

back 8 feet from the High Line platform at

the second floor), features custom-designed

stainless-steel panels with small window

openings. The north and south facades feature

extra-large glass panels measuring up to 111⁄2

feet tall.

As construction progresses, an independent

contractor lasers the structure to produce

surveys on an ongoing basis. “This building is

closer to a Swiss watch than most buildings,”

says Denari. “Ambitions are higher and

tolerances are smaller. None of the steel can be

even slightly out of place.”

Though the forms of each of these buildings are new, the technology that

makes them possible is not. And while they seem to push the limits of

structural engineering, they have only just begun to scratch the surface of

what’s possible for 21st-century buildings.

Prada Boutique Aoyama Tokyo,

Tokyo, Japan,2003, Herzog & de

Meuron, Takenaka Corporation.

structure: S & RC, 7 Fl. above, 2

Fl. below ground

Tod’s Omotesanto Building,

Tokyo, Japan, 1997, Toyo Ito,

network of concrete trees

Hinged frame + core/ outrigger building construction: the stiffness of the structure can be

greatly improved by using story-high or deeper outrigger arms that cantilever from the core

or shear wall at one or several levels and tie the perimeter structure to the core by either

connecting directly to individual columns or to a belt truss. This makes the structure act as

as a spatial structure similar to a cantilever tube-in-tube.

Composite and Mixed

Steel-Concrete Buildings

Allied Bank tower (71 stories),

Houston, 1983, SOM

Trump tower(68 stories), New York, 1982, Swanke Hayden Connel

Trump International Hotel and

Tower (415 m, 1362 ft, 92 floors),

Chicago, 2009, SOM

Visual study of composite

building structures

TUBULAR STRUCTURES

As the building increases in height in excess of circa 60 stories, the slender interior core and the

planar frames are no longer sufficient to effectively resist lateral forces. Now the perimeter

structure of the building must be activated to provide the task by behaving as a huge cantilever

tube. Much credit for the development of the system must given to the eminent structural

engineer Fazlur Khan of SOM in Chicago.

Various types of wall perforations and wall framing for tubes are shown in the next figure:

• Perforated shell tube (j): concrete wall tube, stressed skin steel tube, composite steel-

concrete tube

• Framed tube or Vierendeel tube (H)

• Deep spandrel tube (I)

• Framed tube with belt trusses (L)

• Trussed or braced tube (M)

• Latticed truss tube (N)

• Reticulated cylindrical tube (O)

• Combination (K)

Further organization of tubes according to behavior (cross section):

• Pure tubular concept: Single-perimeter tubes, tube-in-tube, bundled tubes (modular tubes)

• Modified tubes: interior braced tubes, partial tubes, hybrid tubes

The behavior of the cantilever tube

Tubular Structures: various

types of tubular systems are shown:

perforated shell tube ( stressed skin

steel tube, concrete wall tube,

composite steel-concrete tube), framed

or Vierendeel tube, deep spandrel tube,

framed tube with belt trusses, trussed

or braced tube, latticed truss tube, any

combinations. The organization

according to the cantilever cross-

section is: single perimeter tubes, tube-

in-tube, bundled or modular tubes, and

modified tubes (interior braced tubes,

partial tubes, hybrid tubes)

Cook County Administration Building (Brunswick Building), Chicago, 1964, Myron

Goldsmith (SOM), perimeter tube + interior core

One Shell Plaza,

Houston, 1971,

SOM

Standard Oil, Chicago,

Perkins + Will, Edward

Durell Stone

World Trade Center, New York,

1973, Minoru Yamasaki, before

9/11/2001

Shenzhen Stock Exchange HQ, 2011, OMA- Rem Koolhaas

780 Third Avenue Office

Building (50 stories), New

York, 1985, SOM

Alcoa Building (6 stories), San

Francisco, 1967, SOM

Swiss Reinsurance Headquarters,

London, Norman Foster

Hearst Tower, New York, 2005, Foster Associates Architects, Green Highrise: the diagrid frame used 20%

less steel than the average astructure, the building glass has a special coating that lets in natural light

while keeping out the solar radiation that causes heat. It is the double-wall technology that dissipates the

sun's heat; ventilation that runs under the floor rather than through overhead ducts; carbon-dioxide

monitors that assure adequate fresh air; and a system that collects and reuses rainwater and wastewater,

saving 10.3 million gallons of water each year.

John Hancock Center (100 stories, 344 m), Chicago, 1968, Bruce Graham/ Fazlur Kahn (SOM)

Onterie Center, SOM

Sears Tower (110 stories), Chicago, 1974, SOM

Fountain Place (219 m), Dallas, 1986, I.M. Pei, is of elaborate formal geometry where the

perimeter trussed steel frame for the lower 40-story portion is the primary support structure

Bank of America Center (238 m, 56 stories), Houston, 1984, P. Johnson, the tower has the appearance of

three adjoining towers, where the tallest tower consist of a perimeter tube closed on the inside with a

Vierendeel hat truss following the gabled roof line that ties the braced frame of the interior core to the

exterior tube; the intermediate tower consists of a channel-shaped partial tube and the low-rise tower has

a planar welded frame along the end face.

JP Morgan Chase Tower (75 stories,

305 m), Houston, 1982, I.M. Pei, mixed

construction

Messeturm (256 m), Frankfurt/M, 1991, Jahn/Murphy, tube-in-tube in concrete, 50% of wind

moments is carried by the perimeter tube

23 East 22nd Street

Residential High-Rise, New

York City (24-story, 355 ft =

107 m), 2010, Rem Koolhaas

(OMA), WSP Cantor Seinuk

The 355-foot-tall OMA building would tower over its neighbors on 22nd Street, a mostly residential block lined with a mix of

10- to 12-story structures and smaller town houses in the shadow of the Flatiron Building. The original motivation for the

growth spurt in the OMA building’s midsection was to provide a good mix of apartment units—a total of 18 luxury units,

including several duplexes and terraces—with varying floor plans and ceiling heights. OMA’s initial design included a much

more dramatic cantilever. Working from the earliest stages of design development with structural engineers at WSP Cantor

Seinuk, however, OMA modified that element so that the cantilever became more gradual. The first cantilever, on the

seventh floor, where the building sets back slightly, is the greatest, at 10 feet 5 inches, with successive ones above it

stepping out at every other floor for a total overhang of 30 feet 8 inches above the adjacent five-story town house to the

east. (The developer purchased air rights from a number of nearby

Spanning 10 floors of the 24-story building, the cantilever resembles an inverted staircase. At such a scale, the daring

design is impressive, but the concept is an ancient one. In a corbel, which predates vaults, a block or brick is partially

embedded in a wall, with one end projecting out from the face. The weight of added masonry above stabilizes the

cantilever and keeps the block from falling out of the wall. The same theory holds true for this building, though steel

plates are added at each of the cantilevered floors to counter overturning due to lateral, or wind, forces. In the absence of

such forces, the building would be completely stable without additional support because of plans to use post-tensioning

cables to anchor it into the bedrock.

The primary structure of the building, however, is not steel but concrete. The facades are composed of 12-inch-thick, high-

strength structural concrete and act as sheer walls (thinning out to 10 inches above the 21st floor). The structural strategy

can alternately be described as a tube with punched-out window openings or a series of stacked Vierendeel trusses

that form a tube. “The structure fits nicely with the architecture,” explains Silvian Marcus, C.E.O. of WSP Cantor Seinuk.

“Because the floor area is so small, putting the structure in the perimeter keeps the interiors free of columns. It also

suits the architects’ desire for varied fenestration.”

In fact, the vertical window openings, which mimic those of nearby buildings, play a significant structural role. The size of

the openings correlates to moments of stress. In areas under greatest stress, the window spacing is modified to

provide increased structural area and rigidity, supporting the building like a structural corset. In the tower’s

midsection, where the forces generated by the cantilevers are greatest, openings are smallest. There, ceiling heights

are also at their lowest at 11 feet. Where forces are minimal, as at the top of the building, ceiling heights increase to 15 feet,

and openings get bigger, creating loftlike interiors. All of the forces from the upper part of the building travel down the

east and west side walls to the building’s base, where a 46-foot-tall, column-free screening room for the Creative Artists

Agency is located. The box-in-box construction at the base acoustically isolates the screening room from the apartments.

Adds Long, “In some ways, the base is more complicated structurally than the cantilever above.”

MEGASTRUCTURES

AND HYBRID STRUCTURES

The term megastructure refers not to the visionary concepts of the 1960s

expressing the comprehensive planning of a community, but solely the support

structure of a building. However, the megastructure is still formulated on the basic

concept of a primary structure that supports and services secondary structures or

smaller individual building blocks. In the early 1970s, Fazlur Khan proposed to

replace the multicolumn concept by four massive corner column supporting

superframe. Theprinciple can be traced back to the John Hanckock Center in

Chicago.

Study of new generation of structures (hybrid structures): the current trend

away from pure building forms towards hybrid solutions as expressed in geometry,

material, structure layout, and building use, is apparent. In the search for more

efficient solutions for unique conditions, a new generation of structural systems has

developed with the aid of computers which, in turn, have an exciting potential of

architectural expression. Mathematical modeling with computers has made mixed

construction possible, which may vary with building height, thus allowing nearly

endless possibilities that one could have not imagined only a few years ago.

Hotel de las Artes (154 m, 44 floors),

Barcelona, Spain, 1992, SOM/Iyengar,

diagonally braced tube in the form of mega

portal frames

Proposal for the new World Trade Center in New York (2002), Rafael Vinoly

Overseas Union Bank Center (280 m, 63 floors), Singapore, 1986, 280m, Kenzo Tange, hybrid

system of steel frames with concrete walls to increase rigidity (the core consists of hybrid

steel frame with concrete wall zones) allowing for column-free floor space.

Petronas Towers (88 stories, 452 m), Kuala Lumpur, Malaysia, 1996, mixed construction, core-outrigger:

the towers are each framed by a 152-ft (46 m) diameter concrete perimeter tube connected by floor

diaphragms to a high-strength reinforced concrete core nearly 75 ft (23 m) square. The core columns are

connected at the corners to the perimeter tube by four reinforced concrete Vierendeel trusses at the 38th

floor above ground. The slenderness of tower is 8.6!

Petronas Towers (88 stories, 452 m), Kuala Lumpur, Malaysia, 1996, mixed construction, core-outrigger: the

towers are each framed by a 152-ft (46 m) diameter concrete perimeter tube connected by floor diaphragms to a

high-strength reinforced concrete core nearly 75 ft (23 m) square. The core columns are connected at the corners

to the perimeter tube by four reinforced concrete Vierendeel trusses at the 38th floor above ground. The

slenderness of tower is 8.6!

Jin Mao Building (88

stories, 1380 ft), Shanghai,

China, 1999, SOM, recalling the

ancient pagoda forms, gently

stepping back to create a

rhythmic pattern as it rises

upward. The tower is organized

into 8 segments (considered a

lucky number) where each one is

reduced in height by 1/8 of the

base height.

The composite

structure comprises a

concrete core, 8

concrete mega

columns, eight steel

columns, and steel floor

framing.

Visual study of mega structures

Examples of mega-structures: the Bank of Southwest Tower, Houston, proposal, Murp

hy/Jahn + LeMessurier, 1985; Medical Mutual, Cleveland, Stubbins + LeMessurier, 1980

Citicorp Center (59 stories), New York,1977, Stubbins + William LeMessurier

The Bank of Southwest

Tower (82 stories, proposal),

Houston, 1982, Murphy/Jahn,

LeMessurier Struct. Eng.,

Bank of China Tower (369 m, 70 stories), Hong Kong, 1989, I. M. Pei + L. E. Robertson; space-frame

braced tube organized in 13-story truss modules, where the 170-ft (52 m) square plan at the bottom of

the building is divided by diagonals into four triangular quadrants. The mixed construction of the

primary structure consists of the separate steel columns at the corners (to which the diagonals are

connected), which are encased and bonded together by the massive concrete columns. The giant

diagonal truss members are steel box columns filled with concrete.

Visual study of hybrid structures hybrid structures

A NEW GENERATION OF HIGH-RISE

BUILDING STRUCTURES as

ARCHITECTURE

These structures do not use new structure systems, but

employ them in a perhaps innovative fashion.

Hongkong Bank (180 m), Honkong, 1985, Foster + Arup, steel mast joined by suspension

trussesacting in portal frame action

Duesseldorf City Gate (67 m, 19

stories), Duesseldorf, Germany, H.

Petzinka + Fink Arch (and Ove Arup

for preliminary design of structure), is

presented as an introduction to the

new generation of high-rise

structures. The 56 m high interior

open space atrium is a typical

characteristic of this new generation

of urban buildings. The twisted

composition of the rhombus-like

arched building (circa 51 x 66 m in

plan) is laterally supported by two

triangular trussed framed core towers

or mega-columns which are

connected to form three portal frames

that is a Z-like bracing system in plan

view. The steel pipes of the trussed

frames are filled with concrete.

Messe-Torhaus (116 m, 30 floors), Frankfurt, 1985, O.M. Ungers

Seoul Broadcasting Center, Seoul, 2003, Richard Rogers Arch. And Buro Happold Struct. Eng

Samsung Samsung Jongro Tower, Seoul, 1999, Rafael Vinoly

Samsung Jongro Tower, Seoul, 1999,

Rafael Vinoly Arch, Structural Design

Group Co. Ltd, Tokyo, Japan: the 33-story

building is about 157 m high from

foundation level, 35 m wide, and 75 m long.

It consists of a mega-structure, that is three

cylindrical steel cores at the corners of a

triangular plan, which are tied together at

the top by a space frame head truss to form

a portal frame, which encloses infill

framing in between. The innovative glass

curtain (one of the largest in the world) is

suspended on vertical stainless steel rods

supported by cantilevered steel brackets at

the 11th floor and uses glass beams (or

blades) for support. The 45 m hanging

glass and steel curtain comprises panels 1

m tall and 2.2 m wide. The horizontal glass

beams are formed of 5 pieces of tempered

glass and span 11 m between columns.

Tower of the Arabs, Chicago Beach Hotel, Dubai,

United Arab Emirates, 1998 (Atkins & Partners

Overseas); the 56-story (321 m, 1053 ft high)

hotel is constructed on a man-made island

approximately 300 m offshore

Nord Deutsche Landesbank am

Friedrichswall, Hannover, 2002, Behnisch

The 23-story multiuse tower's stepped-

glass profile and giant cantilevers pierce

the skyline of the city's Friedrichswall

district. In addition to an intriguing

appearance, the building features an

environmentally innovative design. A soil-

heat exchanger in the foundation

distributes cool air to upper levels, and a

daylight-redirection system is integrated

into a glare-eliminating sunshade.

New Museum of

Contemporary Art, New

York, 2008, Kazuyo

Sejima + Ryue Nishizawa

/ SANAA, Mutsuro

Sasaki Struct. Engineer

THE NEXT GENERATION OF

SKYSCRAPERS

In many cities of the world the traditional limits of zoning laws, requiring

staggered setbacks, are underway to be changed with structures that taper,

tilt, twist, forms that one could have never imagined providing the designer with

unprecedented ability to manipulate light and space. Other motivations are:

• Sustainable, green buildings

• Active control of seismic and wind vibrations: damping systems

• Wind energy

• Complex computer graphics

Helicoidal Skyscraper, Manfredi Nicoletti, 1974

Business Bay Signature Towers (a 75-

storey office development, 65-storey

hotel; and 55-storey residential building ,

Dubai, 2011, Zaha Hadid, Arup

Phare Tower (68 stories), La Défense, Paris. 2012, Thom Mayne’s (Morphosis, LA)

Shinjuku, Tokyo,

Kenzo Tange, 2009

Dubai Dancing Towers, Dubai, United Arab Emirates

Thompson, Ventulett, Stainback Arch, Arup Eng., The four

towers: Ranging from 54 to 97 floors were inspired by the

flames and movement of candlelight

HIGH-RISE APARTEMENT TOWER (190 m, 623 ft, 54-floor), Malmö, Sweden, 2005,

Calatrava, based in form on the sculpture Turning Torso

Apeiron Hotel (28-floors,

185 m), Dubai. Sybarite

UK

CCTV Headquarters and TVCC Building (234 m, 54-floor),

Beijing, Rem Koolhaas and Ole Scheeren, Arup Eng

GREEN HIGH-RISE BUILDINGS

• sky gardens

• collection of natural energy from daylight, wind, and sun heat:

wind turbines, solar collectors

• materials that store natural energy

• natural ventilation

• facades that reduce the building’s energy load

• etc.

International Prefecture Hall, Fukuoka, Japan,

1996, Emilio Ambasz Arch.: the green building -

garden city - the interaction of nature and

building - building is internally broken up with

atria - terraced gardens along the south side of

the building: the building in a way gives back

to nature what it has taken away – penetration

into the building

Menara Mesiniaga, Subang Jaya,

Malaysia, 1993, Ken Yeang, bioclimatic

design, garden spiral

Fusionopolis (15-story),

Singapore Green

Building, Ken Yeang

EDITT Tower (26-story),

Singapore, 2009-, Ken Yeang.

Residence Antilia (40-story, 245

m), Mumbai, India, 2009, Syed

Mobin Architects

Dancing Apartment, 2009 -, South

Korea, Unsangdong Architects

Commerzbank (259 m, 60 stories), Frankfurt, Germany, 1997, Norman Foster + Arup, the triangular steel

tower has a central atrium where the corner core columns support the Vierendeel trusses which, in

turn, carry the floors and skygarden while allowing column-free interior spaces.

Facades that Reduce the Building’s Energy Load

• Solar control facades

• Day-lighting facades

• Double-skin facades and natural ventilation

• Active façade systems (e.g. demand-responsive programs)

GSW Headquarters (21-story),

Berlin, 1999, Sauerbruch

Hutton, Arup

sky gardens

Headquarter RWE AG (31-story, 127 m), Essen, 1996,

Cristoph Ingenhoven;

Double façade system (breathing wall) is composed

of single pane clear glass fixed at the outside and the

operable double-pane glass inside. A louvered blind is

utilized in the 20-in (50 mm) buffer zone.

Al Faisaliah Tower 1 (44-story, 267 m, 876

ft), 2000, Riyadh, Foster + Happold

Doha High Rise Office Building (45-

STORY), Qatar, 2010, JEAN NOUVEL

The curtain wall is composed of four “butterfly” aluminum elements of different scales. This overall pattern

changes in order to provide maximal protection from the strong east and west sun. In other words, the glass-

clad building is wrapped in a metal brise-soleil based on a traditional Islamic pattern. Butterfly aluminum

elements 'echoing the geometric complexity of the mashrabiyya are set on the facade according to the specific

orientation of each part of the building - 25 % toward north, 40 % toward south, 60 % on east and west. Beneath

this layer, a slightly reflective glass skin complements the system of solar protection. Roller blinds are also

provided inside."

Sony Center am Potsdammer Platz, Berlin, Helmut Jahn, 2000

Sony Center am Potsdammer

Platz, Berlin, Helmut Jahn, 2000

Bahrain World Trade Center (50-

floors, 240 m) , Manama, Bahrain,

2008, Shaun Killa, with the world’s

first integrated wind turbines

Rotating wind power tower (250 m),

2009 - , Dubai, David Fisher, Dynamic

Architecture

The tower will allow each floor to rotate

freely allowing the building to shift its

shape; in between each floor horizontal

wind turbines will allow the building to

produce energy.

SUPER TALL (SLENDER)

BUILDINGS BUILDING AERODYNAMICS

While major innovations in structural systems have permitted the increased

lateral loads to be efficiently carried, the dynamic nature of the wind that is the

phenomenon of vortex shedding, is still a factor, causing discomfort t to

building occupants and causing serious serviceability issues.

Mitigation of wind-induced motions caused primarily by the vortex-shedding

phenomenon, through modification of building aerodynamics:

• modification of building form

• use of auxiliary damping systems

Vortex-shedding phenomenon:

When a building is subjected to a wind flow, the originally parallel

wind stream lines are displaced on both transverse sides of the

building and the forces produced on these sides are called vortices.

At low wind speeds, the vortices are shed symmetrically (at the same

instant) on either transverse side of the building, and the building

does not vibrate in the across wind direction.

On the other hand, at higher wind speeds, the vortices are shed

alternately first from one and then from the other side. When this

occurs, there is an impulse both in the along the wind and across

wind directions. The across wind impulses are, however, applied

alternatively to the left and then to the right. This kind of shedding

which causes structural vibrations in the flow and the across

wind directions is called vortex shedding.

The problem of excessive building motions and their effect on comfort

of the occupants can be more difficult one to solve in the case of very

tall and slender buildings.

Modification of building form:

Investigation into the relationship between the aerodynamic

characteristics of a structure and the resulting wind-induced excitation

level. Aerodynamic modifications of a building’s cross-sectional shape,

the variation of its cross-section with height, or even its size, can

reduce building motion.

• slotted and chamfered corners

• fins

• setbacks

• buttresses

• horizontal and vertical through-building openings

• tapering the shape to reduce the frontal area at the top of the tower

• drop-off corners

• sculptured building tops

Shanghai World Trade Center

(101-story, 494 m, 1622 ft)

Shanghai, 2008, Kohn Pedersen

Fox, L.E. Robertson

92nd floor

87th

floor

Taipei 101 (509 m, 1671 ft, 101 floors),

2004, Taipei, Taiwan, CY Lee &

Partners + Thornton & Tomasetti

Twisting Scyscraper proposal for

Chicago, Calatrava, (2000 ft)

Burj Dubai concrete

tower (818 m, 2684 ft,

160 floors), 2009,

Dubai, United Arab

Emirates, SOM/ Baker

Nakheel Tower (1400 m, 4593 ft, 228 floors), Dubai, United Arab Emirates, 2010 - ,

I.M. Pei/ Woods Bagot + WSP Cantor Seinuk

Nakheel Tower (1400 m, 4593

ft, 228 floors), Dubai, United

Arab Emirates, 2010 - , I.M.

Pei/Woods Bagot + WSP Cantor

Seinuk,

the Capital Gate building

in Abu Dhabi (RMJM

architects

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