Authors: Vandana Kushwaha, Neeti Mishra
Certificate: View Certificate
In this research dynamic analysis of outrigger system was carried out for a 60-storey building having an overall height of 180 m. First of all, comparison of performance between single and multi-outrigger was drawn, then analysis was carried out on different outriggers such as X, V, Inverted V and shear wall. Outriggers were placed according to Taranto theory i.e. (1/n+1), (2/n+1), (3/n+1), (4/n+1) … (n/n+1) of height . Frame with only shear wall core and other outrigger models were analysed in ETABS software and different parameters as Maximum Story Displacement, Maximum Story Drift and Story Shears was compared. By analysing all the models by dynamic analysis for Earthquake Load (Response Spectrum) and static analysis for Wind Load it was concluded that structure becomes more resistive to lateral load with increase in no. of outriggers. Between X, V and inverted V type steel outrigger, inverted V is most effective but when shear wall was used as an outrigger, it gave better results than steel outriggers. Also belt trusses or shear bands increases the effect of outriggers even more.
From the early days of the human civilization migration has been a common part of day-to-day life. Early people travelled thousands of miles in search of food, water and safety. In the modern era people still migrate from one place to other for better job opportunities and lifestyle. As we know big cities and metropolis provides a great deal of life to human these days hence a lot of people are attracted toward the big cities. Due to which the population of these cities are raising ten folds. Supporting a large amount of population in a limited area of land has been a challenge to the society. Different types of land utilization techniques were evolved in the past years, one of these techniques is high rise buildings. High rise building is best land utilization technique in present time it can save a lot of land as the plan of high-rise buildings are very less as compare to the elevation.
With less plan area and more elevation, it has no limitations in vertical direction till sky. A high-rise building is a building having height more than 35 meters. High rise buildings that are taller than 150m are termed as “skyscrapers”, buildings taller than 300m are termed as “Supertall” and buildings taller than 600m are termed as “Megamall”.
But with great advantages there are some great challenges which are faced by engineer daily to make these buildings into reality. One of these challenges is lateral forces i.e., earthquake and wind forces. High rise building consists of a large elevation area than plan which makes them easy target for lateral forces. Hence, they are very venerable to earthquake and wind loads on regular basis. Hence to make high rise buildings safe against lateral loads different types of structural systems are used.
A. Description of the Model
In this research a 60-storey building was considered having 3 m of storey height. Plan dimension was of 38 × 38 m with five bays of 8 × 6 × 10 × 6 × 8 m in both directions. Total height of the building was 180 m. M30 grade of concrete and Fe345 steel was used in different members of structures. Size of the column was taken as 0.8 × 0.8 m and beam of size 0.5 × 0.8 m and for the outrigger beams ISMB250 was used. Slab thickness was kept 0.2 m. Vertical and horizontal loads were calculated as per recommendations of IS 456 , IS1893 (Part1)  and IS-875 (Part 3) . First of all, comparison of performance between single and multi-outrigger was drawn, then analysis was carried out on different outriggers such as X, V, Inverted V and shear wall. ETABS software was used for modelling and analysis purpose, two type of analysis was done i.e., Response Spectrum and Static Wind Analysis.
II. LITERATURE REVIEW
Outrigger is a very old concept but still a lot of things in it are not very clear, this chapter consists of some past researches on outriggers by different authors.
This study compares the behaviour of multi outriggers, effect of belt truss (shear band) on outriggers and effect of different bracings as outriggers. The results of parameters such as maximum story displacement, maximum story drift and story shears are drawn. Hence the conclusions are made as follows With the increase in the no. of outriggers performance of the building also increases and use of belt trusses and shear band with outriggers is more effective than only outriggers. Between X, V and Inverted V type steel outrigger bracing beams, inverted V combined with 4 outriggers is most effective but shear walls are far better than steel bracings.
 Akbar, A., & Azeez, S. (2016). “EFFECT OF OUTRIGGER SYSTEM IN A MULTISTORIED IRREGULAR BUILDING,” 197–203.  Bayati, Z., M. Mahdikhani, and A. Rahaei. \\\"Optimized use of multi-outriggers system to stiffen tall buildings.\\\" The 14th World Conference on Earthquake Engineering, Beijing, China. 2008.  Chen, Yue, and Zhenya Zhang. \\\"Analysis of outrigger numbers and locations in outrigger braced structures using a multi objective genetic algorithm.\\\" The Structural Design of Tall and Special Buildings 27.1 (2018).  Haghollahi, Abbas, Mohsen BesharatFerdous, and Mehdi Kasiri. \\\"Optimization of outrigger locations in steel tall buildings subjected to earthquake loads.\\\" The 15th World Conference on Earthquake Engineering, LISBOA. 2012.  Hasan, R. A. A. J. Behavior Of beam and wall outrigger in high –rise building and their comparison.  Herath, N., et al. \\\"Behaviour of outrigger beams in high rise buildings under earthquake loads.\\\" Australian Earthquake Engineering Society Conference. 2009.  Ho, G. W. M. (2016). The Evolution of Outrigger System in Tall Buildings. International Journal of High-Rise Buildings, 5(1), 21–30. https://doi.org/10.21022/IJHRB.2016.5.1.21  IS:16700-2016. “Criteria for Structural Safety of Tall Concrete Buildings.” New Delhi: Bureau of Indian Standard; 2016.  IS:1893 (Part 1)-2002.” Criteria for Earthquake Resistant Design of Structures Part 1 General Provisions and Buildings (Fifth Revision).” New Delhi: Bureau of Indian Standard; 2002.  IS:456-2000. “Plain and Reinforced Concrete – Code of practice (Fourth Revision).” New Delhi: Bureau of Indian Standard; 2000.  IS:800-2007. “General Construction in Steel – Code of Practice (Third Revision).” New Delhi: Bureau of Indian Standard; 2007.  IS:875 (Part 1)-1987. “Code of Practice for Design Loads (Other than Earthquake) for Buildings and Structures Part 1 Dead Loads – Unit weights of building materials and stored materials (Second Revision).” New Delhi: Bureau of Indian Standard; 1987.  IS:875 (Part 2)-1987. “Code of Practice for Design Loads (Other than Earthquake) for Buildings and Structures Part 2 Imposed Loads (Second Revision).” New Delhi: Bureau of Indian Standard; 1987.  IS:875 (Part 3)-1987. “Code of Practice for Design Loads (Other than Earthquake) for Buildings and Structures Part 3 Wind Loads (Second Revision).” New Delhi: Bureau of Indian Standard; 1987.  Jagadheeswari, A. S., and C. Freda Christy. \\\"Optimum Position of Multi Outrigger Belt Truss in Tall Buildings Subjected to Earthquake and Wind Load.\\\" International Journal of Earth Sciences and Engineering, ISSN (2016): 0974-5904.  Jagadish, J. S., and Teja’s D. Doshi. \\\"A Study on Bracing Systems on High Rise Steel Structures.\\\" International Journal of Engineering Research and Technology 2.7 (2013): 1672-1676.  Jayaram, N. \\\"OPTIMUM POSITION OF OUTRIGGER SYSTEM FOR HIGH RAISED RC BUILDINGS USING ETABS 2013.1. 5 (PUSH OVER ANALYSIS).\\\"  Kamath, Kiran, N. Diva, and Asha U. Rao. \\\"A study on static and dynamic behaviour of outrigger structural system for tall buildings.\\\" Boning international journal of industrial Engineering and Management Science 2.4 (2012): 15.  Kiran Kamath, Avinashi AR, and K. Sandesh Upadhyay. \\\"A Study on the performance of multi-outrigger structure subjected to seismic loads.\\\" IOSR Journal of Mechanical and Civil Engineering e-ISSN (2013): 2278-1684.  Kogilgeri, Srinivas Suresh, and Beryl Shanthapriya. \\\"A study on behaviour of outrigger system on high rise steel structure by varying outrigger depth.\\\" IJRET: International Journal of Research in Engineering and Technology 4.07 (2015): 434438.  Mistry, Krunal Z., and Dhruti J. Dhyani. \\\"Optimum Outrigger Location In Outrigger Structural System For High Rise Building.\\\" International Journal of Advance Engineering and Research Development (IJAERD) Volume 2 (2015).  Mulla, Abdul Karim, and B. N. Srinivas. \\\"A study on outrigger system in a tall RC structure with steel bracing.\\\" International Journal of Engineering Research & Technology (IJERT) Vol 4 (2015).  Nanduri, PMB Raj Kiran, B. Suresh, and MD Ihtesham Hussain. \\\"Optimum position of outrigger system for high-rise reinforced concrete buildings under wind and earthquake loadings.\\\" American Journal of Engineering Research 2.08 (2013).  Patil, Dhanaraj M., and Keshav K. Sangle. \\\"Seismic Behaviour of Outrigger Braced Systems in High Rise 2-D Steel Buildings.\\\" Structures. Vol. 8. Elsevier, 2016.  Safari Gorji, M., & Cheng, J. J. R. (2017). Steel plate shear walls with outriggers. Part I: Plastic analysis and behavior. Journal of Constructional Steel Research, 134, 148– 159. https://doi.org/10.1016/j.jcsr.2017.02.033  Shetty, Anitha Ganesh, and G. Narayan. \\\"EVALUATION OF SEISMIC RESPONSE OF STRUCTURAL SYSTEMS IN HIGH. RISE BUILDING WITH DIFFERENT CONFIGARATION USING ETABS.\\\"  Shivacharan, K., et al. \\\"Analysis of outrigger system for tall vertical irregularities structures subjected to lateral loads.\\\" IJRET 4.05 (2015): 84-88.  Sukesh, H. S., Chandra, H. S. S., Lakshmi, P. S., Student, P. G., Engineering, C., Mandya, P. E. S. E., … Mandya, P. E. S. E. (2017). Influence of Outrigger system in RC Structures for Different Seismic Zones. International Research Journal of Engineering and Technology (IRJET), 4(6), 1749–1752. Retrieved from https://irjet.net/archives/V4/i6/IRJET-V4I6566.pdf  Sukhdev, Shruti B. \\\"Optimum Position of Outrigger in G+ 40 RC Building.\\\" IJSTE- International Journal of Science Technology & Engineering 2.10 (2016): 1051-1055. 30. Taranto, Bungle S. “Reinforced concrete design of tall building.” CRC press, 2009.
Copyright © 2022 Vandana Kushwaha, Neeti Mishra. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.