for the subject offered in GTU, ACE special structures for the 6th sem subject and for the master of construction management

1. SPECIAL
STRUCTURES
Presented by
Karm P Balar
Asst. professor
SSASIT, SURAT

2.  TALL STRUCTURE
– Definition
– Needs of tall structure
– Types of tall structure
– Factor affecting tall structure
– Design consideration of tall structure
– Structural frame system
 URBAN SPATIAL STRUCTURE
– How do we measure USS?
 PRESTRESSED STRUCTURE
– Prestressing effect on beam
– Accessories require for pre-stressing
– Advantages & disadvantages

3. Definition :
A structure or a building having
height more than 80 m is known
as tall structure.
Tall structure are also known as a
skyscraper.
From structural Engineer’s point
of view, a tall building may be
defined as one that, because of
its height it is affected by lateral
forces such as wind force,
earthquake forces.
BURJ KHALIFA SKYSCRAPER

4. The rapid growth of the urban population and the pressure on
limited space have influenced the development of tall
structures.
Tall structure makes distinctive land marks and tall commercial
buildings are developing in city centers as prestige symbols for
corporate organizations.
The business and tourist community with its increasing
mobility has considered the preferable need for more high rise
and city Centre hotel accommodation.
Tall commercial structures are mainly a response to the
demand by business activity to be as close to each other,
especially to the city center areas as possible.

6. Multistorey
residential building
Multistorey commercial
building

7. Multistorey mix purpose
building

8. Cooling tower
High rise elevated
service reservoirTall chimney

9. 1) Availability of construction materials, equipment (mobile cranes,
pumps for concrete)
2) Advancement in new construction technologies
3) Research and development of light weight concrete and light
weight framework
4) Development of skeleton structure
5) Advancement in analysis and design of tall structure
6) Availability of advance design software
7) Development of earthquake resistant structural design
8) Energy dissipation base isolation techniques
9) Increased speed of erection
10) Slip form technique and flying formwork
11) Light partitions, glass curtain walls etc.

10. 1) Loading
2) Floor system
3) Strength and stiffness
4) Storey drift
5) Creep, shrinkage and temperature effects
6) Foundation settlement and soil-structure interation
7) Other important services like ventilation, electric
power supply, air conditioning, heating, water supply
system, waste disposal, vertical transportation (lifts)
etc.

11. 1) Loading :
 The principal loads considered in the design of tall structures are :
• Gravity loads
• Dead loads
• Wind loads
• Earthquake loads
 These forces depends on :
• Size and shape of the building
• Geographical location of building
Dead load Earthquake load
Gravity load Wind load
2) Floor system :
 (a) For R.C.C. structures :
• One way slab on beams & joints
• Two way slab on beams & joints
• Two way flat slab
• Waffle flat slab
 (b) For steel structures :
• One way beam system
• Two way beam system
• Composite steel concrete floor system

12. 3) Storey drift :
The drift in a storey is computed as a difference of deflections of
the floors at the top and bottom of the storey.
When building is subjected to earthquake forces, the floor are
deflected laterally.
The total drift in storey is the sum of shear deformations of that
storey, axial deformation of floor, axial deformation of column and
foundation rotation.
Total drift = S.D + A.D of floor + A.D of column + F.R
Due to the minimum specified design lateral force, the storey drift
in any storey with a partial load factor of 1.0, should not exceed
0.004 times the storey height.
Partial load factor < 0.004 (storey height)
LIMITATION DURING EARTHQUAKE :
To provide human comfort
To limit damage to non-structural elements
To preserve vertical stability of a structural system
To limit the effect of eccentric gravity load
To minimize damage due to pounding

13. 4) Strength and stiffness :
The structure should have proper strength in lateral as well as in
vertical direction. The structure should not collapse even under a
worst combination of loads.
Stiffness is the property of a structure to resist deformation.
Lateral stiffness is the major consideration in the design of tall
structures.
The stiffness of joints particularly in the design of precast or
prefabricated structure, should be given special attention to
develop lateral stiffness of the structure and to avoid progressive
failure.
A brittle structure having more stiffness, proves to be less durable
during earthquake, while a ductile structure performs well in
earthquake.

14. 5) Creep, Shrinkage and temperature effect :
The vertical deformation due to creep and shrinkage may cause
distress in non-structural elements like flooring, cladding,
partition etc.
Temperature difference between the exterior and interior
columns, induces stresses in the structural elements.
6) Foundation settlement and soil-structure interation :
In tall structures gravity forces and lateral forces (earthquake
force, wind force) are very large . So, the foundation should be
capable of transmitting these loads to the under ground strata
without exceeding permissible settlement.
For tall structure deep foundation ( pile foundation, deep caisson
) are provided.

15. Earthquake causes shaking of ground in all three
direction along the two horizontal directions ( X
and Y ) and vertical direction (Z).
There are main four structural systems to resist
lateral loads :
(a)Load bearing wall system
(b)Moment resisting frame system
(c)Dual system ( frame + shear wall/bracing )
(d)Tube systems

16. (a) Load bearing wall system :
• Suitable for low rise building
• Very weak in resisting lateral loads
• Seldom recommended for multi storey building
(b) Moment resisting frame system :
• The ability of multistorey building to resist the lateral
forces depends on the rigidity of joints between the
beams and columns.
• When this joints are fully rigid, the structure is capable
of resisting the lateral loads. The frame is called
moment resisting frame.
• Strength and stiffness are not sufficient

17. • M.R.F. may be strengthened by incorporating the following
structural components such type of system is known as dual
system.
1. Load bearing shear wall
2. Shear wall with column
3. Infilled shear walls
4. Bracing
5. Diaphragms
1. Load bearing shear wall :
• Useful in preventing the failure of non structural component
• May be of RCC, steel, composite and masonry
• Thickness :150 mm , height :400 mm
(c) Dual system :

18. 2. Shear wall with column :
• Provided along both length and width of building
• Vertically oriented wide beams that can carry earthquake loads
from diaphragms and transmit them to the ground
3. Bracing :
• It may be offer lower resistance depending on their design and
construction
• Section may be steel rolled, circular bar or tube
• Vibration may cause the bracing to elongated or compress
• Ductility is very important in designing the bracing
4. Diaphrams :
• Horizontal resisting elements like floors, roofs
• Transfer the lateral forces between vertical resisting elements
• Acts as the web of beam and edges as flanges

19. Pure frame Load bearing shear
walls
Shear wall with
column

20. Infilled shear wall Braced frame Whole building
braced

21. • Building taller than about 40 storey the lateral
force becomes very intense. In this case tube
system is more economical.
• Classification of tube system
1. Framed tube
2. Trussed tube
3. Tube in tube
4. Bundled tube
(d) Tube system :

22. 1. Framed tube system
• closely spaced columns
• tied at each floor level by deep spandrel beams
2. Trussed tube system
• The diagonal members along with grinder and columns, form a
truss system that imparts a great deal of stiffness to the building.
3. Tube in tube
• Consist of an exterior tube that resist the bending moment due to
lateral forces and an interior slender tube, which resist the shear
produced by the lateral forces.
4. Bundled tube
• Made up of a number of tubes separated by shear walls
• The tubes rise to various heights
• Each tube is designed independently

23. FRAME TUBE TRUSSED TUBE BUNDLED TUBE

24. Interior tube
Exterior tube
TUBE IN TUBE

26.  Construction:21 Sept 2004-4 Jan2010
 Design: Adrian Smith and his team
 Place: Chicago office of SOM
(skidmore,owings and Merrill)
 Height: 828 m
 NOS of floors: 160+
 Area of tower: 280,000 sq m
 Total Cost: 4.2 Billion Dollars
 22 million man hours to construct
 Concrete used: 250000 cu.m
 Steel rebars: 39,000 tonnes
 Curtain walls: 83,600 sq.m glass
27900 sq.m of metal

27.  Status: on hold
 Type: Hotel, residential retail
 Location: Marin line,
Mumbai
 Coordinates: 18.950159˚N
72.821348˚E
 Construction: started 2010
 Estimated completion: 2010
 Height: 700 m
 NOS of floors: 126
 Design and construction:
Architect Foster and Partners

28.  Opened : 2010
 Height: 210 m
 Floor: 60
 Address: Mumbai
 Architect: Hafeez
construction
IMPERICAL TOWER

29. PLANET GODREJ
City: Mumbai
Year: 2010
Height: 181 m
Floor: 51

30. RNA MirajMVRDCOrchid Enclave

31. NO. NAME CITY HEIGHT (m) FLOORS YEAR
1. Imperial tower Mumbai 249 60 2010
2. Lodha Bellissimo Mumbai 197 48 Under const.
3. Planet Godrej Mumbai 181 51 2009
4. Ashok Tower I Mumbai 193 49 2009
5. RNA Mirage Mumbai 180 40 2009
6. Oberoi woods tower Mumbai 170 40 2009
7. MVRDC Mumbai 156 35 2009
8. Shreepati acard Mumbai 153 45 2002
9. Vasant polaris Mumbai 151 34 2009
10. Belvedere court Mumbai 149.35 40 2008

32. A cluster of concepts concerned with
“the arrangement of urban public
space.”
Two types of patterns :
I. Spatial pattern of population
distribution within built up area
II. Pattern of population movement
around the city during the day

33. SPATIAL REPRESENTATION OF POPULATION

34. We can define USS using no. of indicators
3 main indicators :
1) Land consumption (density)
2) Density profile
3) Degree of monocentricity (share of trips
with central destination)

35. BUILT-UP DENSITIES AROUND THE WORLD

36. 1) Land consumption per person :
• Higher the density the lower the consumption of
land per person
• Density = city population / built up area
2) Pattern of daily trips within built-up area :
I. Monocentric model (exist only in master plans)
II. Polycentric model (common in North American
Cities
III. Mixed mono-polycentric model (more common)

37. Urban planner should analyse and monitor
the evolution of the city
Planner should identify the type of urban
structure which is compatible with
municipal strategy

38. Definition: The application of
predetermined force or a moment to
structural member in such a manner
that the resulting stresses due to this
force or moment and external loading
will be confined within specified limits

40. I. Pre-tensioning
II. Post-tensioning

41. (a) Pre-tensioning :
• Steel tendons are placed in position in the framework
• Predetermined tensile force P is applied to the tendons are kept in
stretched condition
• Concrete is now placed in formwork and allowed to cure to gets its
design strength
• Tendon become bounded to concrete throughout their length
• The tendon tend to regain their original length by shortening
• Method is useful for small elements like railway sleepers, electric
poles, pipes etc.
Jack
Abutment
Tendon
Beam or block
Prestressing bed
Jack

42. 2) Post-tensioning:
• Concrete is cast while there is no stress in the tendon
• When concrete is hardened, the tendons are stretched through
hydraulic member through hydraulic jacks bearing against the
concrete
• The tendon force is transferred to the member through wedges or
blocks at the end of the member
• The flexible hose or rubber tube may be used to house the tendons
so that bond is not developed between the wires and concrete
• After the tendon has been stressed, the void space between the
tendon and hose is filled with grout
• The tendon becomes bounded to concrete and corrosion of steel is
prevented
Hollow duct for tendon
Anchor plate
Jacking deviceBeam

43. • As the entire prestressed concrete section is in compression, it is
free from tensile cracks
• It eliminates corrosion of steel when structure is expose to
weather
• Pre-stressed concrete section are much smaller than those in
reinforced concrete cement structure, because dead load
moments are neutralised by prestressing moments and shear
stresses are also reduced
• In prestressed concrete, entire section is utilised for resisting loads.
This will reduce the size of members and dead weight of the
structure.
• As the self weight of the structure reduces, the foundation cost will
also reduce
• Under service loads, deflection of member will be less
• It has high live load carrying capacity

44. • It requires high strength concrete (minimum
M-30) and high strength steel
• It requires end anchors and bearing plates
• It requires better quality control
• It requires complicated formwork
• Labour cost may be higher

45. 1. Discuss important points to be considered while constructing tall
structure.
2. Discuss important points to be considered while constructing spatial
structure
3. What is tall structure? What is need of tall structure?
4. List names of any 5 tall structure in India
5. List names of any 5 tall structure in world
6. Enumerate the factor affecting growth, height and structure form of tall
structure
7. Explain various design consideration of tall structure
8. Explain with sketches various structural framing system used for tall
structure
9. What are urban spatial structure?
10. Write short note on ‘urban densities’.
11. What is pre-stressing? Explain concept of pre-stressing.
12. Give advantages and disadvantages of pre-stressing.
13. Explain equipment and accessorises used in pre-stressing.