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1
DEPARTMENT OF ARCHITECTURE
ABUBAKAR TAFAWA BALEWA UNIVERSITY, BAUCHI
ARC 615: ADVANCED BUILDING STRUCTURES
LESSON 7: HIGH RISE BUILDING STRUCTURES
1.1 Introduction
1.2 History of high rise structures
1.3 Generations of structural systems used in high-rise
structures
1.4 Structural systems forms used in high-rise structures
1.5 Advantages and disadvantages of high rise structures
1.6 Structural problems of high rise structures
1.7 Wind loading of high rise structures
1.8 Vertical transportation in high rise structures
1.9 Factors influencing choice of structural system of high rise
buildings
1.10 Foundation design
1.11 Think green
1.12 Examples of high rise structures
1.13 References
1.1 Introduction
1.2 History of High Rise Building Structures
1.2.1 Definition of High Rise Buildings
A multi-story structure between 35–100 meters tall, or a building of unknown
height from 12–39 floors (Emporis Standards)
A building with four floors or more, or 15 to 18 meters or more in height (Indian
Building Code).
Any structure where the height can have a serious impact on evacuation
(International Conference on Fire Safety in High-Rise Buildings).
A building higher than 75 feet (23 meters), or about 7 stories (National Fire
Protection Association).
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Generally, a high-rise structure is considered to be one that extends higher than the
maximum reach of available fire-fighting equipment. In absolute numbers, this is
about 23 meters or about 7 to 10 stories.
1.2.2 Types of High Rise Buildings
Office buildings.
Hotel buildings.
Residential and apartment buildings. An apartment building is a building containing
more than one dwelling unit.
Mixed-use buildings. A mixed-use building may contain offices, apartments,
residences, and hotel rooms in separate sections of the same building.
1.2.3 Demand for High Rise Buildings
Scarcity of land in urban areas.
Increasing demand for business and residential space.
Economic growth.
Technological advancements.
Innovations in structural systems.
Desire for aesthetics in urban settings.
Concept to of city skyline.
Cultural significance and prestige.
Human aspiration to build higher.
1.2.4 Development of High Rise Buildings
Tower of Babel
According to the Old Testament, after the Flood, people wanted to make a name for
themselves by building a city called Babel with a tower that reached into heaven. The
tower was constructed using brick for stone and tar (asphalt) for mortar. This brick tower
was designed so that the “top may reach unto heaven” (Genesis, 11:4), but its building was
discontinued after God confounded their speech and scattered them upon the face of the
3
Earth. The Third Apocalypse of Baruch describes how they “sought to pierce the heavens,
saying, Let us see (whether) the heaven is made of clay, or of brass, or of iron”. The Book of
Jubilees gave the height as 2,484 metres, which is about three times the height of the Burj
Khalifa (Jubilees 10:18-27; Charles, 1913; Wikipedia, 2017x).
Plate 7.1: Artist’s impression of the Tower of Babel by Pieter Bruegel the Elder (1563). Source: Open History Society (2013).
Roman Insula
As early as 3rd century BC.
Five or six stories high (70 Roman feet).
Mostly built with wood frames; and they were so high and poorly built that they
were in constant danger of collapse or destruction by fire.
The skyscraper
Invention of the world’s first safety lift in 1853.
4
In the 1870s, steel frames became available, gradually replacing the weaker
combination of cast iron and wood previously used in construction. Until then, the
walls had to be very thick to carry the weight of each floor.
Foundations: use of piles which were driven into the ground all the way to the
bedrock.
Modern building services: incandescent lamps, central heating, and forced-air
ventilation, followed in the 20th century by fluorescent lights and air-conditioning,
addressed the issue of providing adequate lighting, heating, ventilating, and air-
conditioning.
1.2.5 Tallest Buildings in the World (Chronologically)
Table 1: Chronology of tallest buildings in the World.
Year Name Location
1885 Home Insurance Building Chicago, Illinois
1890 World Building New York City
1892 Masonic Temple Building Chicago, Illinois
1894 Manhattan Life Insurance Building New York City
1898 St. Paul Building New York City
1899 Park Row Building New York City
1908 Singer Building New York City
1909 Metropolitan Life Tower New York City
1913 Woolworth Building New York City
1930 Manhattan Company New York City
1930 Chrysler Building New York City
1931 Empire State Building New York City
1971 – 1973 World Trade Center New York City
1974 Sears Tower Chicago, Illinois
1998 Petronas Towers Kuala Lumpur, Malaysia
2004 Taipei 101 Taipei, Taiwan
2009 Burj Dubai Dubai, United Arab Emirates
1.2.6 Tallest Buildings in the World by 2017 (Top 15)
1. Burj Khalifa (828 m, Dubai, UAE, 2010).
5
2. Makkah Royal Clock Tower Hotel (601 m, Mecca, Saudi Arabia, 2012).
3. Ping An Finance Centre (599 m, Shenzhen, China, 2017).
4. Lotte World Tower (554 m, Seoul, South Korea, 2016).
5. One World Trade Centre (541 m, New York, USA, 2014).
6. Guangzhou CTF Finance Centre (530 m, Guangzhou, China, 2016).
7. Taipei 101 (508 m, Taipei, Taiwan, 2004).
8. Shanghai World Financial Centre (492 m, Shanghai, China, 2008).
9. International Commerce Centre (484 m, Hong Kong, 2010).
10. Changsha IFS Tower T1 (452 m, Changsha, China, 2017).
11. Petronas Towers 1 &2 (452 m, Kuala Lumpur, Malaysia, 1998)
12. Zifeng Tower (450 m, Nanjing, 2010).
13. Suzhou IFS (450 m, Suzhou, China, 2017).
14. Willis Tower formerly Sears Tower (442 m, Chicago, USA, 1974).
15. KK100 (442 m, Shenzhen, China, 2011).
6
Figure 7.x: Top ten world’s tallest buildings by 2014.
7
Plate 7.2: Empire State Building, New York (1931). 102 storeys, 443 m tall. Steel frame, full-width moment frames.
8
1.3 Generations of Structural Systems Used in High-Rise Structures
There are 3 generations of high rise buildings (O’Hagan, 1977).
1.3.1 First generation
The exterior walls of these buildings consisted of stone or brick, although sometimes cast
iron was added for decorative purposes. The columns were constructed of cast iron, often
unprotected; steel and wrought iron was used for the beams; and the floors were made of
wood. Elevator shafts were often unenclosed. There were no standards for the protection
of steel used in the construction of these high-rises.
1.3.2 Second Generation
The second generation of tall buildings are frame structures, in which a skeleton of welded-
or riveted-steel columns and beams, often encased in concrete, runs through the entire
building. This type of construction makes for an extremely strong structure, but not such
attractive floor space. The interiors are full of heavy, load-bearing columns and walls.
Examples: Metropolitan Life Building (1909), the Woolworth Building (1913), and the
Empire State Building (1931).
1.3.3 Third generation
Within this generation there are those of steel-framed construction (core construction and
tube construction), reinforced concrete construction, and steel-framed reinforced concrete
construction.
Steel-Framed Core Construction
These structures are built of lightweight steel or reinforced concrete frames, with exterior
all-glass curtain walls. The so-called curtain walls consist of thin, vertical metal struts or
mullions, which encase the large glass panels constituting most of the wall surface. The
curtain wall, built for lighting and temperature-conditioning purposes, does not have the
strength to stand by itself and is supported by a frame of steel or concrete, which
constitutes the structure of the building (Salvadori, 1980).
Steel-Framed Tube Construction
Tube structures represent a modern change in the design of steel-framed buildings which
enables them to be built extra tall and yet remain strong enough to resist the lateral forces
of winds and the possible effects of an earthquake. Tube construction uses load-bearing
exterior or perimeter walls to support the weight of the building. The key to stability is a
9
resistance to lateral wind or earthquake forces, which grow dramatically in magnitude
with the building’s height. If not counteracted by proper design, these forces would cause a
tall building to slide on its base, twist on its axis, oscillate uncontrollably, bend excessively
or break in two. Because the core and perimeter columns carry so much of the load, the
designers could eliminate interior columns, with the result that there is more open floor
space for tenants. Floor areas tend to be larger, with few partitions using floor-to-ceiling
walls and barriers (Seabrook, 2005).
10
Figure 7.x: Types of Tubular Systems.
11
Reinforced Concrete Construction
Parallel to the development of tall steel structures, substantial advancements in high-rise
structural systems of reinforced concrete have been made since 1945. The first of these
was the introduction of the shear wall as a means of stiffening concrete frames against
lateral deflection, such as results from wind or earthquake loads. The shear wall acts as a
narrow deep cantilever beam to resist lateral forces. Concrete requires no additional
fireproofing treatments to meet stringent fire codes, and performs well during both natural
and manmade disasters. Because of concrete’s inherent heaviness, mass, and strength,
buildings constructed with cast-in-place reinforced concrete can resist winds of more than
320 kilometres per hour and perform well even under the impact of flying debris.
Steel-Framed Reinforced Concrete Construction
These structures are a mixture of reinforced concrete construction and steel-framed
construction, hence the name steel-framed reinforced construction. An example would be a
steel framed structure with a concrete shear core and composite floors built with steel
decking. The term mixed construction is sometimes used to describe this type of high-rise
construction.
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1.4 Structural Systems Forms Used in High-Rise Structures
Figure 7.1: Evolution of Structural System Forms for high Rise Buildings (Lateral Load Resisting Systems).
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Figure 7.x: Steel Structural Systems and the Number of Stories.
Rigid frames: Rigid frames connect the columns and girders by moment-resistant
connections. They resist lateral deformation by joint rotation. They require high
bending stiffness of columns and beams. Rigid joints are essential for stability. They
are not effective for heights over 30 storeys.
14
Figure 7.2: Shear Frame Structural System.
Infilled frames: The reinforced concrete frame of columns and girders is in-filled by
panels of brickwork, blockwork or cast-in place concrete. When subjected to lateral
loads, the infill acts as a strut along the compression diagonal to brace the frame.
Braced frames: In the braced frame system, the lateral load resistance is provided
by the “web” formed by the diagonal members tied to the girders. This creates a
vertical truss, with the columns acting as the chords. The horizontal shear is
resisted by the horizontal component of the web members. This system is highly
efficient and economical in resisting lateral loads for any height of building,
including the very tallest.
15
Figure 7.2: Braced Frame Structures.
Shear walls: Shear walls made from reinforced concrete may serve as both
architectural and structural partitions, capable of carrying gravity and lateral loads.
Their very high in-plane stiffness and strength make them ideal for bracing tall
buildings. In a shear wall building, the shear walls are the primary lateral load
resistance. Shear walls act as vertical cantilevers in the form of separate planar
walls and non-planar assemblies, typically around elevator, stairs and service
shafts. Shear walls are stiffer than rigid frames, and are economical to about 55
stories.
Figure 7.3: Shear Wall Structural System.
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Figure 7.4: Shear Wall Structural System.
Wall frame: The combination of shear walls and rigid frames is called a wall-frame
structure. The structure is constrained to adopt a common deflected shape to both
systems through the horizontal rigidity of the girders and slab. The walls and frame
interact horizontally, especially at the top, to produce a stiffer and stronger
structure. The combination increases the economy of height to the 65 story range,
well above the range of rigid frames or shear walls alone. Most wall-frames are
reinforced concrete. However, steel buildings may use the braced frame to offer
similar benefits of horizontal interaction.
Framed tube: The essence of the framed-tube are the four very stiff moment-
resisting frames that form the “tube” around the perimeter of the building. The
frames consist of closely spaced columns, typically 2 to 4 m, tied together by
horizontal deep spandrel girders. The outer tube carries 100% of the lateral loads,
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and 75 to 90% of the gravity loads. The remaining gravity load is carried by the
small cluster of core columns (or shear walls). This form is the most significant
modern development in tall buildings. Examples are the World Trade Centre, Sears
Tower, Petronas Towers and the Burj Khalifa.
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19
Bundled Tube Structures: The natural evolution of the framed tube form was the
use of several tubes bundled together “like tied sticks”. A bundled group of tubes
provides greater strength that a single tube. These bundled tubes were first tried by
Fazlur Khan in Chicago, when the Sears tower was finished in 1974. The new
internal webs greatly reduce the effect of shear lag in the flanges. Therefore, the
column stresses are more evenly distributed than in a single tube structure. The
bundled tubes thus provide a much larger lateral stiffness, albeit at the expense of
internal planning.
Figure 7.5: Bundled Tube Structural System.
Plate 7.3: Burj Khalifa, Dubai: Example of Bundled Tube Structural System.
20
Figure 7.6: Sears Tower, Chicago: Example of Bundled Tube Structural System.
21
Plate 7.4: Sears Tower, Chicago: Example of Bundled Tube Structural System.
Braced Tube Structures: The efficiency of the framed tube structures can be
improved by adding diagonal bracing to the faces. This results in greater heights
and greater spacing between the perimeter columns. The first steel braced tube was
Chicago’s 97-story John Hancock building, finished in 1969. Because the diagonals
of a braced tube are connected to the columns at each intersection, they virtually
eliminate the effects of shear lag in both the flange and the web frames. As a result,
22
the structure behaves under lateral loads more like a braced frame, greatly
diminishing the bending in the members of the frames. Columns may have greater
spacing, allowing for much greater windows than with a conventional tube.
23
Outrigger braced: This system consists of a central braced core, which is either a
braced frame or shear walls, plus horizontal cantilever “outrigger” trusses or
girders that connect the core to the outer columns. When the structure is loaded
horizontally, the vertical plane rotations of the core are restrained by the outriggers
through tension in the windward columns and compression in the leeward columns.
The outriggers join the columns to the core to make the structure behave as a partly
composite cantilever. The perimeter columns can also participate in the outrigger
24
action by joining all the perimeter columns with the horizontal truss or girder
around the face of the building at the outrigger level. Typically, the outrigger level is
two-stories in depth and thus are usually used to harbor the building’s MEP
systems. The outrigger system has been used to 70 stories in height. If the building
has greater side dimensions, this form could reach much greater heights. The
efficiency of this form depends on how well are the perimeter columns tied to the
core through the outrigger structure.
Figure 7.7: Outrigger structural system.
25
Figure 7.8: Taipei 101. Outrigger structural system.
26
Plate 7.6: Taipei 101. Outrigger structural system.
Suspended Structures: A suspended structure consists of a central core with
horizontal cantilevered outrigger trusses at the roof level, from which are
suspended vertical hangers of steel cables. The floor slabs are connected to these
cables. This permits the ground floor to be exempt of any perimeter columns,
thereby allowing an open concourse. The cables have very small cross-sectional
areas compared to columns, and can be embedded around window sills. Another
advantage is the casting of the floors at ground level and then raised into position.
27
The system is limited to relatively small heights (about 10 to 15 stories) because of
structural disadvantages, such as live-load floor-to-floor connection variations, and
limited core dimensions.
Core Structures: A single core serves to carry the entire gravity and horizontal
loading. It is similar to the suspended building, provides a column-free perimeter at
ground level. However, it is highly inefficient.
Figure 7.9: Core Structure System.
Core or Tube-in-Tube Structures: A variant of the framed-tube form is the
replacement of the inner, or core columns and walls, with another tube. Thus, the
hull (or external tube) and the new core tube act jointly to resist both gravity and
lateral loads. This improved form is called a tube-in-tube, or a hull-core structure. A
steel building could provide a core tube made up of braced frames, whereas a
reinforced concrete building would consist of an assembly of shear walls for the
28
core. The outer framed tube (hull) and the inner core interact horizontally as the
shear and flexural components of a wall-frame structure. This provides the benefit
of a greatly increased lateral stiffness. The outer tube (hull) of course always
dominates, because of its greater structural depth. It is presumed that this form
could push the heights to an economical 120 stories. An example is the Taipei 101
Building in Taiwan.
Plate 7.7: Lumbago Tatung haji Building, Kuala Lumpur. Example of Tube in Tube Structural System.
Space Structures (Space Frames): The space frame serves the dual function of
resisting gravity and lateral loads, thereby becoming one of the most efficient
structural forms. Its lightweight and high efficiency permit these frames to reach
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the greatest heights. A notable example is Hong Kong’s 76 story Bank of China
building. Space frames are usually complex to analyse, and difficult to provide
proper load transfer connections between the floors and the main frame. These
connections are costly and sometimes awkward. One solution is to have an inner
braced core, which serves to collect the lateral loads and the inner region gravity
loading, from the slabs over a number of multi-storey regions. At the bottom of each
region, the lateral and gravity loads are transferred out to the main joints of the
space frame. These structures are very pleasing aesthetically and have great appeal
to architects and the general public.
30
31
32
33
Plate 7.5: Bank of China, Hong Kong: Example of Bundled Tube Structural System.
Hybrid Structures: The modern trend in architecture, especially the so called
postmodern building, is to create non-regularly shaped buildings. The structural
engineer will find these structures do not conform to a single form. Analysis must
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therefore use several combinations of the previously discussed forms. The structure
may comprise for example, of a tube and outrigger system superimposed on each
other, or of a tube system on three faces with a space frame on a faceted fourth face.
The improvements in both computer hardware and software, permit us to
approximate acceptable solutions to these complex structures.
1.5 Advantages and disadvantages of high rise structures
1.5.1 Advantages of high rise structures
Reduced Cost
Use tall buildings decreases land price per capita, street cost per capita, and cost
of underlying facilities
Save costs of construction and reduced cost of residential units
Compressed cities decrease volume of infrastructures of cities and reduce costs
Perspective
Possible creation of cozy and relaxed atmosphere far from crowdedness; urban
perspective
Due to visual highlight, high rise buildings can help orientation of cities
Prevention of Horizontal Extension
Decreased suburban development and decreased damage to environment
A suitable model for housing in cities facing limited physical horizontal
extension
Social
Possible creation of suitable space for improving social facilities and urban
services
1.5.2 Disadvantages of high rise structures
Environmental
Environmental pollutions due to vehicle congestion
Destroy nature and environment in case of incorrect location
35
Tall buildings block fresh air circulation and sunlight (Rahnama et al, 2014).
Traffic
Increased traffic volume due to increased plot ratio of tall buildings
Increased distance between place of occupants, because of erected tall
residential
complexes as mass building projects
Social
Social degeneration, social isolation and alienation in tall residential complexes
Decreased health social relations among occupants of tall buildings due to their
scale and nature
Cultural
Spatial limitation of tall buildings prevents activities rooted in local culture from
being accomplished
Incompatibility of ideology and culture of occupants of tall buildings with their
spaces
Priority of high rise buildings over low rise ones
Safety
Vulnerability of tall buildings relative to low rise buildings against accidents
such as earthquake
In cases where such accidents as fire occur, the fire will spread
Possibility of accidents including falling down the stairs and falls from height
Health
Pressure from weight of tall building breaks soil layers and connects sewage
networks with groundwater supplies
Existence of car parking lots in a closed space in tall buildings makes pollution
stable.
Aesthetic
36
Erection of tall buildings near each other prevents natural perspectives such as
sunrise and sunset, from being seen from low rise buildings
Mass building of tall blocks causes the environment to be drab
1.6 Structural problems of high rise structures
Strength of materials.
Proportion of structural area to useable space.
Wind loading.
Seismic activity.
Vertical communication.
1.7 Wind loading of high rise structures
1.7.1 Building Shapes and Aerodynamics
Rectangular
Circular
Triangular
37
Figure 7.10: Drag Coefficients of various Building Shapes
Figure 7.11: Vortex Shedding Effects
1.7.2 Modification to Building Shapes to reduce Wind Effect
Stair Step Corner
Through Building Openings
Rotate ad Twist
38
Plate 7.8: Rough Corner can Reduce Vortex Shedding Effects.
39
Plate 7.9: Openings reduce wind forces (reduced ‘sail area’).
40
Plate 7.10: Rotate to minimize load from prevailing direction. Twist avoids simultaneous vortex shedding along height.
41
1.7.3 Damping and Dynamics
Damping directly reduces building accelerations
Some damping inherent in construction (Concrete framing > steel framing)
When inherent damping is not sufficient, provide supplementary damping
Dampers occupy space : Quantity and location based on modes to be treated
Costs include purchase, installation, tuning, maintenance, inspection.
Figure 7.12: Tuned mass damper.
1.7.4 Seismic activity and high rise structures
Seismic Design Issues
Less critical than wind for tall building with long natural period (minimum base
shear may govern seismic)
Inter-story drift (maximum at upper floors)
Ductile detailing still important!
Geometric compatibility
Performance Based Design
1.8 Vertical transportation in high rise structures
1.8.1 Types of vertical transportation in high rise structures
Stairs
42
Elevators
Escalators
Ramps
1.8.2 Elevator Planning
Building access plays a crucial role in the development and feasibility of high-rise
construction plans. Internal transportation systems function as the building’s main artery,
determining the functionality and quality of life within the tower block, yet they also result
in a considerable loss of rentable floor space on each level. Moreover, the elevator core is
often the building’s support structure, especially in narrower constructions. For this
reason, it is very important that a traffic flow specialist be involved in the initial orientation
phases of a high-rise construction project, as well as the developer, architect and structural
engineer. Specifications for internal transportation must be drawn up whereby routing and
usage remain logical, while occupying as little space as possible. Above all, the capacity
required for stairs, elevators and shafts need to be determined (Deerns Consulting
Engineers, 2017).
1.8.3 Elevator Design Criteria
Height of the building and its individual storeys.
Distribution of the population throughout the building.
Main entrance levels (points of entry and exit).
Distribution of population over elevator groups (if the same destination can be
reached using more than one group).
Stair usage.
1.8.4 Primary Considerations for Estimating Elevator Group Requirements:
Number of elevators per group.
Nominal elevator load capacity (based on car floor area).
Realistic car occupancy.
Nominal elevator speed.
1.9 Factors Influencing Choice of Structural System of high Rise Buildings
Time for design and planning
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Construction time
Cost of construction
Life cycle cost: the present value of the total cost of a building over its operating life,
including initial capital cost, occupation cost, operating cost and the cost incurred
derived from the disposal of the building at the end of its life.
Fire safety
Acoustics
Installation of service systems (MEP, HVAC).
1.10 Foundation Design
Intensive soil investigation and analysis
Concentrated building weight affecting strength and settlement studies
Construction sequences
Model deep basement “anchor” against overturning vs. baseline at top of mat
Pile depths – verticality
Dewatering for deep basements
44
1.11 Think Green
Plate 7.11: EDDIT Tower, Singapore.
45
Plate 7.12: O14, Dubai
46
1.12 Examples of high rise structures
Figure 7.x: Examples of Steel Structural Systems.
47
Plate 7.13: The Petronas Towers, Kuala Lumpur, Malaysia. Source: Author’s photograph (2011).
48
Plate 7.14: The Burj Khalifa in Dubai. Standing at 930 metres, this remains the tallest building and the tallest man-made structure in the world. Source: Author’s photograph (2011).
49
Empire State Building, New York, USA
Burj Al Arab, Dubai (Occupied: 197 m, to tip: 321m).
50
51
Hearst Tower by Norman Forster, 300 W 57th Street, New York, USA (182 m).
52
53
54
1.13 References
Charles, R. H. (1913). The Book of Jubilees. In: The Apocrypha and Pseudepigrapha of the
Old Testament, Clarendon Press, Oxford.
O’Hagan, J. T. (1977). High Rise/Fire and Life Safety. 2nd printing. Saddle Brook, NJ: Fire
Engineering, A PennWell. Pp 145-146.
Open History Society (2013). Tower of Babel – Donald Trump. Retrieved from
http://www.openhistorysociety.org/wp-content/uploads/2012/06/Tower-of-Babel-
Donald-Trump1.jpg.
Salvadori, M. (1980). Why Buildings Stand Up: The Strength of Architecture . New York: W.
W. Norton; p. 22.
Seabrook, J. (2001). The Tower Builder, Why did the World Trade Center buildings fall
down when they did? The New Yorker. November 19, 2001:66.
Wikipedia (2017). Tower of Babel. Retrieved from
http://en.wikipedia.org/wiki/Tower_of_Babel.