Tall structures are defined as buildings over 50m or 14 stories tall. Rapid urban growth and limited land availability have driven the construction of ever taller buildings for business, prestige, and tourism. Structural systems for tall buildings must effectively resist both vertical and lateral loads. Common high-rise structural systems include rigid frames, flat plates, cores, shear walls, braced frames, outriggers, tubes, and megaframes. System selection depends on height, with tubes and outriggers enabling the tallest structures over 40 stories. Floor systems also vary between one-way and two-way slabs for steel or concrete construction.

1. SEMINAR REPORT
ON
STRUCTUR
AL
ARRANGEM
ENT
OF
TALL
Under the Guidance:
PROF. (DR.)DIPANKAR
CHAKROBORTY
DEPARTMENT OF CIVIL
ENGINEERING
JADAVPUR UNIVERSITY

2. INTRODUCTION
DEFINITION OF TALL STRUCTURES
• Tallness is a relative matter
• its structural analysis and design are in some way
affected by the lateral loads
• According to the CTBUH,
 Buildings of 14 storeys or 50 m height+:-“tall
buildings”;
 buildings of 300 m + : “super tall buildings”;
 buildings of 600 m + : “mega tall buildings”

3. WHY TALL BUILDINGS:
• Rapid growth of urban population and consequent pressure
on limited space.
• Business activities close to each other and to the city
center putting intense pressure on available land.
• Prestige symbols
• High cost of land, desire to avoid continuous urban sprawl
• Preserve important agricultural production.
• Attraction of tourists such as hotels, restaurants and watch
towers.
• Local Topographical restriction such as Hong Kong, Rio De
Janeiro

4. Tallest 20 in 2020 (ref.: CTBUH projection)
• Competitors
− You may want to allocate one slide per
competitor
• Strengths
− Your strengths relative to competitors
• Weaknesses
− Your weaknesses relative to competitors

5. LATERAL LOAD DESIGN PHILOSOPHY
• In contrast to vertical load, lateral load
effects on buildings are quite variable
and increase rapidly with increases in
height.
• There are three major factors to consider
in the design of all structures:
• strength,
• rigidity, and
• stability

6. CONCEPT FOR PREMIUM FOR HEIGHT
• the material required for the vertical system, such as
column; and walls, in a high-rise structure is substantially
more than that for a low-rise building.
• The material increases in the ratio (n + 1)/2, where n is the
number of floors

7. THE STRUCTURAL SYSTEMS OF TALL
BUILDINGS
• Rigid frame systems
• Flat plate/slab systems
• Core systems
• Shear wall systems
• Shear-frame systems
shear trussed frame (braced frame) systems
shear walled frame systems
• Mega column (mega frame, space truss) systems
• Mega core systems
• Outriggered frame systems
• Tube systems
• framed-tube systems
• trussed-tube systems
• bundled-tube systems.

8. Tall Building Structural System and tentative number of
floors they reach efficiently and economically
10 20 30 40 >40
Rigid frame systems
Flat plate/slab systems with columns and/or shear walls
Core systems
Shear wall systems
Shear-frame systems
(shear trussed /braced frame systems & shear walled frame
systems)
Mega column (mega frame, space truss) systems
Mega core systems
Outriggered frame systems
Tube systems

9. Rigid frame structures
• capable of resisting both vertical and lateral loads
by the bending of beams and columns.
• beam-column connections should have adequate
rigidity
• it is necessary to have closely spaced columns, and
for the beams connecting them to be sufficiently
deep
• In rigid frame systems ductility is achieved by the
formation of plastic hinges in the columns and
beams
• disadvantage in rigid frame systems is the
magnitude of lateral drift,

10. the 16-storey, 65 m high Ingalls
Building (Cincinnati, 1903)

11. Flat plate/slab systems.
• Using a flat ceiling instead of beams, and thus
attaining the maximum net floor height.
• In resisting lateral loads, flat plate/slab systems
may be insufficient
• The addition of shear walls to flat plate/slab
systems mitigates this problem.

12. Flat plate/slab systems: (a) without column capitals, (b) with column capitals, (c)
with gussets

13. Core systems
• This system consists of a reinforced concrete core shear wall
resisting all the vertical and lateral loads.
• In core systems, floor slabs are cantilevered from the core
shear wall independently or else cantilevered modules of
floor slabs are used

14. • Core systems efficiently and economically
provide sufficient stiffness to resist wind and
earthquake induced lateral loads in buildings
of up to about 20 storeys;
• “Mega core systems”, which are made with
much thicker core shear walls than normal,
can be used efficiently and economically in
buildings of more than 40 storeys.

15. • Shear wall systems:
• used in reinforced concrete buildings.
• Shear wall systems efficiently and
economically provide sufficient stiffness to
resist wind and earthquake induced lateral
loads in buildings of up to about 35 storeys.

16. Shear Frame System
• Vertical shear trusses (braces) and/or shear
walls are added to the rigid frame to carry
the external shear induced by lateral loads

17. Frame systems can be divided into two types:
• shear trussed frame (braced frame) system
• shear walled frame system

18. • Provide a greater stiffness than a system of
“shear truss / shear wall” or “rigid frame”
acting alone .

19. • Provide sufficient stiffness to resist wind and
earthquake induced lateral loads in buildings of
more than (as well as below) 40 storeys.
(a) Shear trusses / shear walls in plan, (b) partially closed cores in plan

20. • Seagram Building, New York, USA, 1958

21. Shear trussed frame (braced frame) systems
• consist of rigid frames and braces in the form of
vertical trusses

22. Shear walled frame systems
• consist of rigid frames and reinforced concrete shear
walls that are perforated or solid

23. Mega column (mega frame, space truss) systems
• horizontal connections are of primary
importance.
• to support this behaviour of restraining the
columns laterally, belts, vierendeel frames, and
mega braces are used.
• all external mega columns and/or shear walls
are connected together to participate in the
lateral stiffness of the structure

24. Mega column (mega frame, space truss) system

25. Mega core systems
• core shear walls with much larger cross-sections than
normal, running continuously throughout the height of
the building
Slabs in the mega core system: (a) cantilever slab, (b) supported cantilever
slab

27. Outriggered frame systems
• Outriggers are added to shear-frame systems with core (core-frame
systems) so as to couple the core with the perimeter (exterior)
columns.
•

29. Hinged connections between outriggers and perimeter
columns increase the efficiency of the system by maximising
the utilisation of not only the moment resisting capacity of the
shear core but also the axial capacity of the columns.

30. Evaluation of outrigger frame systems

31. Tube systems
• The tube system can be likened to a system in which a hollow
box column is cantilevering from the ground, and so the
building exterior exhibits a tubular behaviour against lateral
loads.
• closer spacing of the perimeter columns
• increasing the depth of the spandrel beams connected to the
perimeter columns
• adding shear trusses/braces or shear walls to the core
• adding an inner tube in place of the core (tube-in-tube)
• adding a truss (multi-storey braces) to the building exterior
(trussed-tube)
• combining more than one tube (bundled-tube).

32. Tube systems can be divided into three types:
• framed-tube systems
• trussed-tube systems
• bundled-tube systems.

33. Framed-tube systems
Configurations of the ground floor in the framed-tube system

35. Trussed-tube systems
• In order to increase the spacing between the columns without
inhibiting the tubular behaviour, connecting the perimeter
columns with exterior multi-storey braces led to the
development of the trussed-tube (braced-tube) system

36. Bundled-tube systems
• in bundled-tube systems, the increase in the cross-sectional
dimensions at the ground floor in order to control the slenderness
of the building makes it possible to reduce the cross-sectional
dimensions by different amounts throughout the height of the
building.
• In bundled-tube systems formed from framed-tubes and/or
trussed-tubes, greater building heights and wider column spaces
are obtained than in framed-tube systems.

37. • 442 m high Willis Tower (Chicago, 1974)

38. FLOOR SYSTEMS
• One way slab on beams and walls
• . One-Way Pan Joists and Beams.
• One-Way Slab on Beams and Girders
• Two-Way Flat Plate
• Two-Way Flat Slab
• Waffle Flat Slabs
• Two-Way Slab and Beam

39. FLOOR SYSTEMS—STEEL FRAMING
One-Way Beam System
Two-Way Beam System
Composite Steel-Concrete Floor Systems

41. Concluding Remarks:
• First half of the twentieth century were the braced frame.
• These forms have now been augmented by a variety of other
forms that allow structures of greater efficiency and height to
be achieved in both steel and concrete.
• Advances have occurred mainly in the use of shear walls,
framed tubes, large-scale braced systems, and space frames,
and in better recognizing and accounting for the various types of
vertical and horizontal interaction between the major vertical
components In these mixed forms, combinations of two or more
of the single forms are used to fit the "postmodern" buildings'
irregular shapes or cut-outs.