Analysis and design of the sky scraper structure subjected to earthquake load using software etabs 2

Scientific Journal of Impact Factor (SJIF): 3.134

E-ISSN (O): 2348-4470 P-ISSN (P): 2348-6406

International Journal of Advance Engineering and Research Development Volume 2, Issue 12, December -2015

ANALYSIS AND DESIGN OF THE SKY SCRAPER STRUCTURE SUBJECTED TO EARTHQUAKE LOAD USING SOFTWARE ETABS 2015 Pratik S. Bhandari1,Anuj K. Chandiwala2 1 2

Civil Engineering Department, Chhotubhai Gopalbhai Patel Institute of Technology Civil Engineering Department, Chhotubhai Gopalbhai Patel Institute of Technology

Abstract — Effect of Earthquake on sky scraper structures shows that if the structures are not well designed and constructed with and adequate strength it leads to the complete collapse of the structures. Specific lateral loading due to earthquake load along with vertical gravity loads is important for finding the behavior of the tall buildings. As the height of a building becomes taller, the amount of structural material required to resist lateral loads increases drastically. The design of Sky scraper buildings essentially involves a conceptual design, approximate analysis, preliminary design and optimization, to safely carry gravity and lateral loads. The design criteria are strength, serviceability and human comfort. The aim of the structural engineer is to arrive at suitable structural schemes, to satisfy these criteria. In the present study, the limit state method of analysis and design of Sky scrapers under seismic load as per IS codes of practice is described. Analysis and design the Sky scraper structure under the effect of earthquake force by using ETABS-2015 that is the ultimate integrated software package for the structural analysis and design of buildings. Indian standard code of practice IS-1893 (Part I: 2002) for earthquake guidelines and methodology are used to analyzed and designed building.

Keywords- Sky scraper structure, Seismic force, Response Spectrum Analysis.

I.

INTRODUCTION

Developing of the sky scraper structure in world increasing drastically, which is going to add in the history of World’s Tallest Structures. Developing the sky scrapers start at a very early stage. In general, for design of Sky scraper buildings both wind as well as earthquake loads need to be considered. Governing criteria for carrying out dynamic analyses for earthquake loads are different from wind loads. According to the provisions of Bureau of Indian Standards for earthquake load, IS 1893(Part 1):2002, height of the structure, seismic zone, vertical and horizontal irregularities, soft and weak storey necessitates dynamic analysis for earthquake load. The contribution of the higher mode effects are included in arriving at the distribution of lateral forces along the height of the building.[3]

Figure 1. World’s Tallest Structures II.

LITERATURE REVIEW

A. Seismic Analysis of the World's Tallest Building; Journal of Constructional Steel Research 65 (2009) 1206_1215 Hong Fan, Q.S. Li, Alex Y. Tuan, Lihua Xu; ―Study On Taipei 101 (officially known as the Taipei Financial Center) with 101 stories and 508 m height, located in Taipei where earthquakes and strong typhoons are common occurrences, is currently the tallest building in the world. The great height of the building, the special geographic and environmental conditions, not surprisingly, presented one of the greatest challenges for structural engineers. In particular, its dynamic @IJAERD-2015, All rights Reserved

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International Journal of Advance Engineering and Research Development (IJAERD) Volume 2, Issue 12, December -2015, e-ISSN: 2348 - 4470, print-ISSN: 2348-6406 performance under earthquake or wind actions requires intensive research. The structure of the building is a mega-frame system composed of concrete filled steel tube (CFT) columns, steel brace core and belt trusses which are combined to resist vertical and lateral loads. In this study, a shaking table test was conducted to determine the constitutive relationships and finite element types for the CFT columns and steel members for establishing the finite element (FE) model of the tall building. Then, the seismic responses of the super-tall building were numerically investigated. An earthquake spectrum generated for Taipei Basin was adopted to calculate the lateral displacements and distributions of interior column forces.‖ Furthermore, time-history analyses of elastic and inelastic seismic response were carried out using scaled accelerograms representing earthquake events with return periods of 50-year, 100-year, and 950-year, respectively. The computational results indicate that the super-tall building with the mega-frame system possesses substantial reserve strength, and the high-rise structure would satisfy the design requirements under severe seismic events.

Figure 1. Plan of belt-trusses.

At the end authors concluded The seismic analysis results of the super-tall building indicated that the structural system, with belt trusses at every eighth or tenth story, provides equal stiffness along the height of the building, which can decrease the lateral deformation efficiently. For such a mega-frame structural system with a central braced core connected to perimeter columns on each building face, the total dead and live loads at every floor are transferred to the sloping exterior columns, thereby the structural capacity to withstand lateral loading is enhanced. The results of this research also showed that Taipei 101 has relatively high earthquake resistance and could guarantee the structural safety under a seismic action with a moderate seismic fortification, as stipulated in the local seismic design code.

B. Drift Analysis due to Earthquake Load on Tall Structures; Journal Of Civil Engineering And Construction Technology ISSN 2141-2634 @2012 , Volume-4(5), page number 154-158, May 2012.

A. Rahman, A. A. Masrur Ahmed and M. R. Mamun;― Due to shaking of ground surface, the substructure as well as the superstructure is vibrated. During earthquake, there will be a drift on the high rise structures. Then it can be included that the more the height, the more the drift. The drift of the structure decreases with increase in the width of the structure.

So our concern is to calculate the drift of tall structures due to the vibration of ground. The analysis and design of tall @IJAERD-2015, All rights Reserved

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International Journal of Advance Engineering and Research Development (IJAERD) Volume 2, Issue 12, December -2015, e-ISSN: 2348 - 4470, print-ISSN: 2348-6406 building are affected by lateral loads, particularly drift or sway caused by such loads. Drift or sway is the magnitude of the lateral displacement at the top of the building relative to its base.‖ For rigid frame structures, the drift are depended on total building height, number of spans, cross sectional length and width of girder, cross sectional length and width of column, and shear value of girder and shear value of column. For couple shear wall structures, the drift are depended on total building height, length of wall, width of wall and length of beam between two wall. For wall-frame structures, the drift are depended on total building height, number of span, length of span, dimension of core and cross section of beam.

Value of drift

Figure 2. Variation of drift with building height.

Value of drift

Width of Wall

Figure 3. Variation of drift with Width of Wall.

Value of drift

Length of Wall Figure 4. Variation of drift with Length of Wall. @IJAERD-2015, All rights Reserved

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International Journal of Advance Engineering and Research Development (IJAERD) Volume 2, Issue 12, December -2015, e-ISSN: 2348 - 4470, print-ISSN: 2348-6406 The conclusion of the thesis includes, According to the specialist, there is possibility to occurrence of earthquake. So the tall structures are on the threat, due to earthquake drift occurrence. So every high rise structure should consider the effect of drift. Then the loss of life and property will be attenuated. Estimation of drift was carried out for rigid frame structure, coupled shear wall structure and wall frame structure. This study indicates that the drift on high rise structures has to be considered as it has a notable magnitude. So every tall structure should include the drift due to earthquake load as well as wind load.

C. Seismic Performance of Super Tall Buildings; International Conference on Sustainable Built Environment (ICSBE-2010) Kandy, 13-14 December 2010 Nilupa Herath, Priyan Mendis, Tuan Ngo, Nicholas Haritos; 窶標ith the rapid population growth and dynamic economic developments, the demand for residential, mixed use and commercial buildings has been increasing significantly all around the world. Due to the excessive increase in height of buildings in this era, there is a significant impact on the methods used to analyze and design of tall buildings. There is a clear acceptance within the engineering community that the specifications given in codes of practice are not suitable for very tall buildings. General concepts, current methods of analysis and seismic performance of super tall buildings are reviewed in this paper. Further the effect of higher modes on the performance of super tall buildings is also discussed.

Figure 5. Demand and capacity spectra

Figure 6. General Response Spectrum

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International Journal of Advance Engineering and Research Development (IJAERD) Volume 2, Issue 12, December -2015, e-ISSN: 2348 - 4470, print-ISSN: 2348-6406

Figure 7. Acceleration response spectra at 5% damping for the five spectrum-compatible earthquake records In this paper, general concepts and widely used seismic analysis methods (Displacement based method, N2 method, Capacity Spectrum Method), It is shown that these methods may not be directly applicable to super tall buildings due to the higher mode effects. The phenomenon of higher-mode period lengthening has been illustrated through the non linear dynamic analysis of a 300m tall building. This work is continuing at the University of Melbourne.

D. Study of Seismic and Wind Effect on Multi Storey R.C.C., Steel and Composite Building; International Journal Of Advances in Engineering And Technology, ISSN 2231-1963,Vol.6, Issue 4, Page no: 1836-1847 (Sep 2013) Baldev D. Prajapati & D. R. Panchal; “Engineers, designers and builders are trying to use different materials to their best advantage keeping in view the unique properties of each material Structurally robust and aesthetically pleasing building are being constructed by combining the best properties at individual material & at the same time meeting specific requirements of large span, building load, soil condition, time, flexibility & economy high rise buildings are best suited solution. Also Wind & Earthquake (EQ) engineering should be extended to the design of wind & earthquake sensitive tall buildings. This paper discusses the analysis & design procedure adopted for the evaluation of symmetric high rise multi-storey building (G+30) under effect of Wind and EQ. forces. In these building R.C.C., Steel, & Composite building with shear wall considered to resist lateral forces resisting system.‖ NOTATIONS:• (S+B) = Steel + Bracing • (SSBC) = Steel secondary beam composite • (SSBC+B) = Steel secondary beam composite + Bracing • (SABC) = Steel all beam composite • (SABC+B) = Steel all beam composite + Bracing Author conclude that S.F. & B.M. is more in the RCC, STEEL & (S+B) building. But, when we use the composite beam in the (SSBC), (SSBC+B), (SABC) & (SABC+B) building the forces are reduced due to the reduced the section.

Displacement is within the limits for all building RCC, STEEL and COMPOSITE. Support reaction is maximum in the RCC building which linearly reduce to RCC to (SABC+B) building in the WIND, EQ. ZONE-III and EQ. ZONE-IV type building.

Composite steel-concrete is relatively a new design concept in the Indian context and no appropriate updated codes are available for the design of same. The present work not only eliminates the costly experimentation required but also facilitates design with multiple options for the steel sections and shear connectors with adequacy checks.

III.

CONCLUSION

From the above literature we conclude that @IJAERD-2015, All rights Reserved

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International Journal of Advance Engineering and Research Development (IJAERD) Volume 2, Issue 12, December -2015, e-ISSN: 2348 - 4470, print-ISSN: 2348-6406 1) Earthquake force must be consider while designing of any Sky scraper structure.

2) Composite structure suits the best option for Sky scraper structures.

3) If we consider the earthquake force while designing sky scraper structure, we can control major damages while earthquake occurs.

4) Value of drift, roof displacement, base shear, max shear force, max bending moment must be within the permissible limit.

REFRENCES [1] Hong Fan, Q.S. Li, Alex Y. Tuan, Lihua Xu. Seismic Analysis of the world's Tallest building. Journal of Constructional Steel Research 65 (2009) pp. 1206-1215 [2] A. Rahman, A. A. Masrur Ahmed and M. R. Mamun. Drift analysis due to earthquake load on tall structures.

Journal of Civil Engineering and Construction Technology Vol. 4(5), pp. 154-158, May 2012 [3] K. Rama Raju, M.I. Shereef, Nagesh R Iyer, S. Gopalakrishnan4. Analysis and design of RC tall building subjected to wind and earthquake loads. The Eighth Asia-Pacific Conference on Wind Engineering, December 10–14, 2013.

[4] Nilupa Herath, Priyan Mendis, Tuan Ngo, Nicholas Haritos; Seismic performance of super tall buildings; International Conference on Sustainable Built Environment (ICSBE-2010) Kandy, 13-14 Dec 2010.

[5] Mohamed A. A. El-Shaer . Seismic Load Analysis of different R.C. Slab Systems for Tall Building. International Journal of Current Engineering and Technology. Vol.3, No.5, (December 2013) [6] Dr. S.K. Dubey , & P.D. Sangamnerkar . Seismic behaviour of assymetric rc buildings. International Journal of Advanced Engineering Technology. E-ISSN 0976-3945. Vol.2, Issue 4, Oct-Dec 2011, Page no: 296-301.

[7] Xin Zhao, & Lang Qin. Embodied Carbon Based Integrated Optimal Seismic Design for Super Tall Buildings with Viscoelastic Coupling Dampers. International Conference on Sustainable Design, Engineering and Construction ScienceDirect Procedia Engineering 118 ( 2015 ) 223 – 231 [8] Anupam Rajmani & Prof Priyabrata Guha. Analysis of wind & earthquake load for different shapes of high rise building. INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND TECHNOLOGY (IJCIET) Volume 6, Issue 2, February (2015), pp. 38-45.

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