Presentation on COMPARATIVE STUDY OF OUTRIGGER STRUCTURE WITH DIFFERENT CONFIGURATIONS made by Nilesh Prajapati under guidance of Ms Pooja Mistry & prepared by Jugal Senghani at #33NCCE #IEIGSC

1. COMPARATIVE STUDY OF
OUTRIGGER STRUCTURE WITH
DIFFERENT CONFIGURATIONS
PREPARED BY
JUGAL S. SENGHANI
Str. Design Engineer at
Post Tension Services India
Pvt. Ltd., Vadodara.
GUIDED BY
MS. POOJA MISTRY
Assistant Professor at
Government Engineering
College, Bharuch.
2ND
AND 3RD
SEPT. 2017
3333rd
NATIONAL CONVENTION OF CIVIL ENGINEERSNATIONAL CONVENTION OF CIVIL ENGINEERS
INSTITUTION OF ENGINEERS (I)INSTITUTION OF ENGINEERS (I)
GUJARAT STATE CENTRE,AHMEDABAD.GUJARAT STATE CENTRE,AHMEDABAD.
PRESENTED BY
NILESH V PRAJAPATI
Designs (R&B) circle,
Roads & Building
Department, Gandhinagar.

2. PRESENTATION OUTLINES…PRESENTATION OUTLINES…
INTRODUCTION
BACKGROUND
BENEFITS OF OUTRIGGER SYSTEM
OBJECTIVE OF PRESENT STUDY
ANALYSIS AND GRAPHICAL REPRESENTATION
CONCLUSION
REFERENCES

3. INTRODUCTIONINTRODUCTION
• What is outrigger?
Outrigger is a connecting and tying member between two structural member, which is
generally core of building and peripheral columns.
The outrigger system typically engages the core with columns to increase the lateral
stability and stiffness of a building.
It is also defined as a, rigid horizontal structural members to improve building
overturning stiffness and strength by connecting the building core to a peripheral
columns.

5. • The explanation of building outrigger behaviour is simple because outriggers act as
stiff arms engaging outer columns, when a central core tries to tilt, its rotation at the
outrigger level induces a tension- compression couple in the outer columns acting in
opposition to that movement.
• The result is a types of restoring moment acting on the core at that level.
• Analysis and design of a complete core-and-outrigger system is not that simple,
distribution of forces between the core and outrigger system depends on the relative
stiffness of each element.

6. BACKGROUNDBACKGROUND
• Outrigger have been used in tall, narrow building for nearly half a century, but the
design principle has been used for millennium.
• The oldest “outrigger” are horizontal beams connecting the main canoe-shaped hulls of
Polynesian oceangoing boats to outer stabilizing floats.
• A narrow boats hull can overturn when tossed by unexpected waves, but small amount
of upward resistance or weight (downward resistance) acting through outrigger
leverage is sufficient to avoid overturning. Same phenomenon we can apply to the
building by connecting the core and perimeter columns.

7. BENEFITS OF OUTRIGGERBENEFITS OF OUTRIGGER
SYSTEMSYSTEM
• Reduction in deformation of building.
• Reduction in storey drift.
• It increases the lateral stability of structure.
• Force reduction at core foundation.

8. OBJECTIVE OF PRESENTOBJECTIVE OF PRESENT
STUDYSTUDY
• To minimize the lateral displacement of high-rise RC building.
• To finding out the optimum location of Outrigger structural system for high-rise RC
building to resist the seismic load and wind load.
• For combining the strength of outrigger system and shear wall system to withstand the
lateral load.
• To increase the stability of structure by tying the two main structural elements.

9. STUDY MODELSTUDY MODEL
Types of models for 30 storey building
•Type of models with shear wall and outrigger-belt truss at different positions

10. Plan view of bare frame
STUDY MODELSTUDY MODEL

11. Plan view of Shear Wall at centre +corner
STUDY MODELSTUDY MODEL

12. STUDY MODELSTUDY MODEL
View of Structure with outrigger at 20th
storey

13.  COMPARISON TOP STOREY DISPLACEMENT BETWEEN STRUCTURE WITH
AND WITHOUT OUTRIGGER FOR 30 STOREY BUILDING.
Type of
structure
Top Storey Displacement (mm)
At 10th
storey At 20th
storey At 30th
storey
Bare frame 134 283.2 370.2
SW at core 98.6 222.4 310.5
SW at core + corner 66.1 170.4 262.3
RCC Outrigger at 10th
storey 78.8 185 277.1
RCC Outrigger at 20th
storey 100.1 203.6 270.8
RCC Outrigger at 30th
storey 99.4 223 297.1
Results and DiscussionResults and Discussion

14.  GRAPHICAL REPRESENTATION OF STOREY
DISPLACEMENT
Continue…

15.  Graphical representation of Top Storey Displacement
Continue…

16. Continue…
 Graphical representation of Storey Drift Ratio

17.  Comparison of Base Shear
Continue…
Base Shear
Bare frame SW at core
SW at core+
corner
RCC
Outrigger at
10th
RCC
Outrigger at
20th
RCC
Outrigger at
30th
X-Dir
kN
X-Dir
kN
X-Dir
kN
X-Dir
kN
X-Dir
kN
X-Dir
kN
Base Shear 12134.65 13545.78 17652.09 14182.55 13856.14 13953.91
Weight 413091.7 418132.6 438265.1 419819.5 419819.5 419819.5

18.  Graphical representation of Base Shear
Continue…

19. COMPARISON BETWEEN STRUCTURE WITH
RCC AND STEEL OUTRIGGER FOR 30 STOREY
BUILDING.
Storey
RCC Outrigger
at 10th
RCC
Outrigger at
20th
RCC
Outrigger at
30th
Steel
Outrigger a
10th
Steel
Outrigger at
20th
Steel
Outrigger at
30th
X-Dir
mm
X-Dir
mm
X-Dir
mm
X-Dir
mm
X-Dir
mm
X-Dir
mm
Storey 10 78.8 100.1 99.4 82.9 98.4 99
Storey 20 185 203.6 223 192.3 205.3 222.1
Storey 30 277.1 270.8 297.1 281.9 277.1 297.9
 Comparison of Top Storey Displacement

20. Continue…
 Graphical representation of Storey Displacement

21. Continue…
 Graphical representation of Storey Displacement

22. Continue…
 Graphical representation of Top Storey
Displacement

23. Continue…
 Graphical representation of Top Storey Displacement

24.  Comparison of Base Shear
Continue…
RCC
Outrigger at
10th
RCC
Outrigger at
20th
RCC
Outrigger at
30th
Steel
Outrigger at
10th
Steel
Outrigger at
20th
Steel
Outrigger at
30th
X-Dir
kN
X-Dir
kN
X-Dir
kN
X-Dir
kN
X-Dir
kN
X-Dir
kN
Base Shear 14182.55 13856.14 13953.91 13795.11 13643.26 13700.52
Weight 419819.5 419819.5 419819.5 418457.4 418457.4 418457.4

25.  Graphical representation of Base Shear
Continue…

26. Comparison between structure with RCC Outrigger
and Belt truss at different positions.
 Comparison of Top Storey Displacement

27. • Above results shows the comparison of storey displacement, storey drift ratio and base
shear for Bare Frame, Frame with shear wall (different location of shear wall) and
outrigger systems (different locations and patterns).
• Outrigger structural system is effective when outrigger beam is placed at its optimum
location.
• In 30 storey building optimum position of outrigger was found at 20th
storey.
• Structure using shear wall at center and corner gives the less displacement than the
structure with single outrigger at its optimum position, but its base shear is very higher
than structure with outrigger system.
• Therefore outrigger structural system is more economical and effective than the shear
wall.

28. CONCLUSIONCONCLUSION
• From the comparison for storey drift, it can be concluded that location of outrigger
beam gives the least storey drift at that storey.
• Comparison has been made between RCC & Steel Outrigger systems for 10th
, 20th
, 30th
storey locations in 30 storey building, conclusion can be made that RCC Outrigger
gives less displacement than steel outrigger.
• Therefore RCC outrigger is more effective than Steel outrigger
• Material for outrigger like RCC and Steel does not give major difference in base shear.

29. FUTURE SCOPEFUTURE SCOPE
• Same structural configuration can be used for steel structure and composite section as a
outrigger beam.
• Buildings with irregularities can be further proposed to this lateral load resisting systems.
• This subject further can be elongated for the study in wind along with dynamic wind
effect.

30. ACKNOWLEDGEMENTS
• I am thankful to Shri. S. K. Patel sir , Additional Secretary & Chief Engineer,
R & B Department, And Director-STC , Government of Gujarat, Gandhinagar, for his
Excellency, valuable support, Guidance and continuous inspiration for the paper.
• The work carried out in the Department of Civil Engineering,C.S.P.I.T, Charusat
University, Changa,during the course of M.tech. By Jugal Senghani guided by Ms.
Pooja Mistry and me. We really thankful to the Department of Civil
Engineering,C.S.P.I.T, Changa.

31. REFERENCESREFERENCES
1. Agarwal, P. & Shrikhande, M., 2006. Earthquake Resistant Design of Structures. Delhi: PHI learning Private Limited.
2. Bungale, T. S., 2010. Reinforced Concrete Design of Tall Building. s.l.:CRC Press is an imprint of Taylor & Francis Group.
3. Choi, H., Ho, G., Joseph, L. & Mathias, N., 2012. Outrigger Design for High-Rise Buildings. Chicago: Council on Tall Buildings and Urban
Habitat.
4. Chopra, A. K., 2007. Dynamics of Structures. 3rd ed. s.l.:person education, Inc.
5. Gursale, M. & Patil, P. S., 2015. Comparative Parametric Study of Linear and Nonlinear Behavior of Multisory Structures. International
Journal of Research in Engineering and Technology, 4(4).
6. Herath, N., Haritos, N., Ngo, T. & Mendis, P., 2009. Behaviour of Outrigger Beams in High rise Buildings under Earthquake Loads.
Australian Earthquake Engineering Society.
7. Kamath, K., N, D. & Rao, A. U., 2012. A Study on Static and Dynamic Behavior of Outriggr Structural System for Tall Building. Bonfring
International Journal of Industrial Engineeringand management Science.
8. Patel, D., Amin, J. A. & Shah, N. D., n.d. A Parametric Study on Effectiveness of Shear Wall Patterns in Reducing Lateral Displacement &
Inter Storey Drift.
9. Shah, H. J., 2014. Reinforced Concrete. 7th ed. s.l.:Charotar.
10. Shivacharan, K., Chandrakala, S., Narayana, G. & N, K., 2015. Analysis of Outrigger system for tall vertical irregularites structures
subjected to lateral loads. International Journal of Research in Engineering and Technology.