Seminar presentation of tube frame structions,

2. TUBE FRAME
STRUCTURES
SUBMITTED BY
ZAFRIN MOHAMED
ROLL.NO:77
S7 CE B
GUIDED BY
Mrs. VARNA K THANKAPPAN
ASSISTANT PROFESSOR
IIET,NELLIKUZI

3. CONTENTS
• Introduction
• Need for high rise buildings
• Different configurations
• Advantages
• Disadvantages
• Brief explanation of shear lag
• Conclusion
• References
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4. INTRODUCTION
• Introduced by Fazalur Khan,Dhaka
Bangladesh
• Hollow cantilever perpendicular to
the ground
• Buildings in excess of 40 stories
• A 43-story Khan-designed De-Witt
Chestnut Apartment in Chicago
• Steel, concrete, or composite
construction
TUBE FRAME STRUCTURES
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TUBE FRAME STRUCTURES
De-Witt Chestnut Apartment,
Chicago

6. Need for tall structure
• Increase in building height
• Slenderness
• Building weight reduction
• Limited availability of land
• Rapid increase in cost of land
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TUBE FRAME STRUCTURES

7. CONCEPT OF TUBULAR
SYSTEM
• Design of strength, rigid and stable
structures
• Largely economic solution
• Building designed for resisting lateral loads
• Hollow cantilever perpendicular to ground
• Incarnation of the tubes
• Exterior-Columns and beams forms a rigid
frame
• Interior-simply framed for gravity loads
• 50% of windows on exterior wall surface 5/26
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TUBE FRAME STRUCTURES

8. Defining tube frame
• Predict the structural behavior
• Replace 3D system by equivalent
plane frame
• Analysed by conventional methods
• Comparison of results- 15 story
Perspex model of the building
• Deciding the type of configuration
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TUBE FRAME STRUCTURES

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TUBE FRAME STRUCTURES
Configuration of Tubes
• Framed or box tube
• Braced tube
• Tube in tube
• Bundled tube

10. The Framed Tube
• The frames consist of closely spaced
columns,
2 - 4 m between centers, joined by deep
girder .
• Act as perforated chimney or stack
• Lateral resistance is by the stiff moment
resisting frames
• Gravity load shared by interior and
exterior columns
• Appropriate for buildings having 40-100
storeys
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TUBE FRAME STRUCTURES

11. Tube frame structures
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Cont..
• Grid like facade structures and is repetious
• Use of prefabrication possible
• Larger distance of exterior column from
NA resists bending moment
• Economically attractive and possess
torsional rigidity
• Greater flexibility in space planning
• A well known example-World Trade Centre

12. CASE STUDY OF WORLD TRADE CENTRE
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TUBE FRAME STRUCTURES
• Architect:-Minoru
Yamasaki
• 110 story tower
• 415m in height
• 50,000 employees
and 80,000 visitors
daily
• Twin tower in
diagonal
juxtaposition

13. Cont…
• vertical extrusions of square plans
• The framed tube consist of 56 box steel
columns joint by moment resisting
connections
• The overall dimensions of framed tube
column are constant
• Wall thickness increases from top to
bottom to increse response to loads
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TUBE FRAME STRUCTURES

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TUBE FRAME STRUCTURES
Braced Tube Structures
• Further improvement of framed tube
• Cross bracing frame with x braces over
many stories-(fig)
• First used in John Hancock building,
Chicago-(fig)
• Diagonals of a braced tube connect
columns at each intersections
• Shear lag is virtually eliminated
• Spacing for columns are increased
• Depth of girders are small

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CIVIL DEPT.IIET NELLIKUZHI
John Hancock Building, Chicago

16. Cont…
• Large sized windows are allowed
• Braces transfer axial load from highly
stressed column to low stressed
column
• Hence eliminates difference between
load stress
• Large scope of architecture .uses a
structural-architectural concept
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TUBE FRAME STRUCTURES

17. Tube-in Tube Structures
• Consist of outer framed tube together with
an internal elevator and a service core
• Inner tube would be braced frames
• Outer tube has greater structural depth, so
plays dominant role
• Outer tube-hull (fig)
• Inner tube –core
• Inner tube holds elevator and other
services
• Another tube around the exterior
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TUBE FRAME STRUCTURES

18. Cont…
• 780 third avanue,Metro Manhattan
office space is the first work
• Concrete shear wall for bracing in the
hull(fig)
• Off centre core allowing column free
interiors
• Accuracy,reliability and simplicity are
verified
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core
hull

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TUBE FRAME STRUCTURES
Metro Manhattan Office
Space

21. Bundled Tube
• Consists of multiple tubes instead of
1.
• Several tubes tied up to resist lateral
forces
• Interior columns on the parameters
of the tube (fig)
• Willis Tower, Burj Khalifa are best
examples
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TUBE FRAME STRUCTURES

22. Cont..
• Highly efficient in
economic terms
• Bundled together
in different sorts of
grouping
• Not necesserily
box shaped
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23. Willis Tower
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Burj Khalifa

24. Advantages of TFS
• Allows greater flexibility in planning of
interior space
• Regularity in the column schedule allows
off-site fabrication and welding
• maximum advantage is taken of the total
width of the building to resist overturning
moment
• Identical framing for all floors
• When well designed, tubular forms uses
same amount of material as in a half large
structure
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TUBE FRAME STRUCTURES

25. Criticism of TFS
• Reduces the size of the opening in
the building .
• At greater heights,view of outer
world is obstructed
• Shear lag
• Linear distribution of axial forces
across flange and web varies
• closely spaced columns are not
encouraged and undesirable
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26. Shear lag
• Occurrence of non uniform
axial stress distribution
Features:-
• Positive shear lag
• Negative shear lag
• Negative shear lag-buckling
on the compression side
&cracking on tension side.
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27. Conclusion
• The provision of adequate, stiffness,
particularly lateral stiffness is a major
consideration In the design of a tall
building hence TFS are engineers favorite
• But structural cost of the TFS may be high
with respect to conventional shear wall
structure
• so necessary to do research for cost
comparison between TFS and conventional
shear wall
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28. References
1. Er. Nahant Rana,et.al.” Structural Forms Systems for Tall Building
Structures,SSRJ”, International Journal Of Civil Engineering (SSRG IJCE),
September 2014volume issued4
2. Hardin J. Patel,et,al. “Braced Tube Structural System: A review”
International Journal of Scientific & Engineering Research, December-2015, ,
Volume 6, Issue 12.
3. R. Mahjoub,et,al, “Simple Analysis of Tube Frame System of Tall Building by
Using Deformation Functions”. Australian Journal of Basic and Applied
Sciences, February 2011. [324-332]
4. Reza Mahjoub,et.al“Analysis of Tube Frame System of Tall Building by
Using of Deformation Functions”. Australian Journal of Basic and Applied
Sciences, 5(8): 1475-1482, 2011.
5. Sharadrao Patil,et.al, “Shear Lag in Tube Structures”. IJISET - International
Journal of Innovative Science, Engineering & Technology, March (2015), Vol.
2 Issue 3,
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