Prof. Wolfgang Schueller
VERTICAL BUILDING STRUCTURES
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, 17th18th 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
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 4/15/2016 84 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 lateralforce 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 (Lateralforce 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 crosssection 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 largepanel 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 crosswall-, 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 singlemodule 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 14story 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 loadcarrying 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 gravityload 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 tightened 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 15.75inch-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, megaframes, 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, HentrichPetschnigg
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'
Analysis of frames 7 Sp @ 25 ft = 175 ft
15 Sp @ 12' = 180'
2(180)/3 = 120'
180/2 = 90'
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
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 60story 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
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-ofright, 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, guywires 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 steelconcrete 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 crosssection is: single perimeter tubes, tubein-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, highstrength 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
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
Nord Deutsche Landesbank am Friedrichswall, Hannover, 2002, Behnisch The 23-story multiuse tower's steppedglass 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 soilheat 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 75storey 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
Headquarter RWE AG (31-story, 127 m), Essen, 1996, Cristoph Ingenhoven; sky gardens
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 (45STORY), 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 glassclad 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 (50floors, 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 - ,
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
