Study on Dynamic Behaviour of High Riser Dual System with In-Plane Discontinuity in Vertical Elements Resisting Lateral Loads
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This study analyzes the dynamic behavior of high-rise dual systems with in-plane discontinuities in vertical elements resisting lateral loads. Three types of reinforced concrete structures are modeled - a regular frame, a frame with shear walls, and a frame with discontinuous shear walls. The structures are analyzed for heights of 20, 40, and 60 stories using equivalent static analysis and time history analysis in ETABS. Results show that shear walls reduce time period but increase stiffness. Taller structures have increased displacements, drifts, and base forces. Structures with discontinuous shear walls have smaller responses than regular frames, but perform worse than continuous shear wall structures above 40 stories.
![International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 04 Issue: 10 | Oct -2017 www.irjet.net p-ISSN: 2395-0072
© 2017, IRJET | Impact Factor value: 6.171 | ISO 9001:2008 Certified Journal | Page 954
where shear wall cannot be arranged for from the
foundation level.
Considerable increase in columnandbeamforcesin
shear wall and in-plane discontinuity structures.
The time history analysis results infers that,
Reinforced concrete frame with in-plane
discontinuity structure displays enhanced
performance in decreasing the peak displacement
up to 40 storey, above 40 storey RC frame with
shear wall systems improved performanceinfalling
the peak displacements. Hereafter it can be
determined that, above 40 storey, in-plane
discontinuity structure will have a lesser amountof
stability compared to shear wall structures.
5. REFERENCES
[1]. Sarkar P, Prasad A Meher, Menon Devdas, “Vertical
geometric irregularity in stepped building frames ”,
,Engineering Structures 32, (2010) , page no.2175–2182.
[2]. Karavallis, Bazeos and Beskos, “Estimation of seismic
inelastic deformation demands in plane steel MRF with
vertical mass irregularities ”,Engineering Structures 30,
(2008), page no. 3265–3275.
[3]. ChintanapakdeeC.andChopra A.K.,“Seismic Responseof
Vertically Irregular Frames: Response History and Modal
Pushover Analyses”, Journal of Structural Engineering,
ASCE, Vol. 130, (2004), issue 8, page no. 1177-1185.
4]. Das, S. and Nau, J.M, “Seismic Design Aspects of Vertically
Irregular Reinforced Concrete Buildings”,Earthquake
Spectra, Vol. 19, (2003), No. 3, page no. 455-477.
[5].Fragiadakis, M., Vamvatsikos, D. and Papadrakakis, M,
“Evaluation of the Influence of Vertical Irregularities on the
Seismic Performance of a Nine-Storey Steel Frame”,
Earthquake Engineering & Structural Dynamics, Vol. 35,
(2006) ,No. 12, page no. 1489-1509.
[6].Ruiz, S.E. and Diederich, R, “The Mexico Earthquake of
September 19, 1985 – The Seismic PerformanceofBuildings
with Weak First Storey”, Earthquake Spectra, Vol. 5, (1989),
No. 1, page no. 89-102.](https://image.slidesharecdn.com/irjet-v4i10168-171128091708/85/Study-on-Dynamic-Behaviour-of-High-Riser-Dual-System-with-In-Plane-Discontinuity-in-Vertical-Elements-Resisting-Lateral-Loads-6-320.jpg)
Study on Dynamic Behaviour of High Riser Dual System with In-Plane Discontinuity in Vertical Elements Resisting Lateral Loads
- 1. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 04 Issue: 10 | Oct -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 6.171 | ISO 9001:2008 Certified Journal | Page 949 STUDY ON DYNAMIC BEHAVIOUR OF HIGH RISER DUAL SYSTEM WITH IN-PLANE DISCONTINUITY IN VERTICAL ELEMENTS RESISTING LATERAL LOADS Manasa B R1, M R Suresh2 1Post Graduate student in Structural Engineering, Dr. AIT, Bengaluru, 560056, Karnataka, India. 2 Associate Professor, Dept. of Civil Engineering, Dr. AIT, Bengaluru, 560056, Karnataka, India. ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - The purpose of the existent examination is to conduct Equivalent Static analysis and Time history Analysis (THA) of vertically irregular RC building frames and to conduct the seismic analysis that relates to Equivalent static analysis and Time history analysis. Five categories of irregularities namely mass irregularity, stiffness irregularity, vertical geometry irregularity. In-Plane Discontinuity in Vertical Elements Resisting Lateral Force andDiscontinuityin Capacity were contemplated. 1. INTRODUCTION In the course of seismic tremors, failure of structure evolves at factors of weak point. This weak spot arises due to discontinuity in mass, stiffness, and geometry of the structure. the systems having this discontinuity are termed as irregular structures. Irregular systems make a contribution to a huge part of city infrastructure. Vertical irregularities are one of the major reasons of disasters of structures in the course of earthquakes. For example systems with soft storey had been the maximum exquisite structures which collapsed. So, the effect of vertical irregularities inside the seismic overall performance of structures will become definitely important. Height-wise adjustments in stiffness and mass render the dynamic characteristics of these buildings distinct from the normal building. When such structures are builtinexcessiveseismic zones, the evaluation and design turns into extra complicated.IS 1893 defines vertical anomalies. 1.1 INPLANE DISCONTINUITY In an in-plane discontinuity ,in-plane offset of the lateral force resisting elements will be greater than the length of those elements. 1.2 DUAL SYSTEM A dual system is a structural system in actual fact whole frame delivers sustenance for gravity loads, and conflicts lateral loads afforded by a particularly detailed moment- resisting frame and shear walls or bracedframes.Bothshear walls and frames play a part in resisting the lateral loads ensuing from earthquakes or wind or storms, and the portion of the forces resisted by each one be contingent on its rigidity, modulus of elasticity and its ductility, and the prospect to develop plastic hinges in its parts. The moment- resisting frame may be either steel or concrete, but concrete intermediate frames cannot be used in seismic zones 3 or 4. 1.3 OBJECTIVES 1 To study the consequence of in-plane discontinuity of vertical components resisting lateral loads, shear walls are reflected as vertical elements. 2. In-plane discontinuity are well thought-out as per the provisions given in IS 1893-2002, norms for seismic resistant design of structure foralteredheightsforzone 5. 3. Shear walls in ground floor and upper floors consists of in-plane discontinuity, and influence of this in-plane discontinuity on conduct of high rise RC structure is studied in assessment with regular RC frame without in-plane discontinuity. 4. Equivalent Static and time historyanalysisisconducted to find out the responses using ETABS Software 1.4 METHODOLOGY 1. RCC building with square planoftotal measurement of 40 m × 40 m ,is studied currently. 2. Three forms of RCC structures are considered. One regular RC frame, second shear wall frame and third shear wall with in-plane discontinuity. 3. The above 3 structure aremodeledandanalyzedfor three diverse heights of 20, 40 and 60 storey, each storey being 3 m in height. 4. Lateral loads as per IS 1893- 2016arewell-thought- out, consigned and responses are tabulated,graphs are plotted. 5. Dynamic time history outcomes are tabulated. 6. Lastly, inferences are made.
- 2. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 04 Issue: 10 | Oct -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 6.171 | ISO 9001:2008 Certified Journal | Page 950 2. MODELLING AND ANALYSIS The common method of modeling the regular structure is illustrated. The same modeling practice employed to model the different other configurations, to study the seismic performance of various structural configurationofstructure. Model 1: Regular building. – 20 storey Model 2: Regular building with Shear wall – 20 storey Model 3: Regular building with Shear wall and in plane discontinuity – 20 storey. Model 4: Regular building – 40 storey. Model 5: Regular building with Shear wall – 40 storey. Model 6: Regular building with Shear wall and in plane discontinuity – 40 storey. Model 7: Regular building. – 60 storey. Model 8: Regular building with Shear wall – 60 storey. Model 9: Regular building with Shear wall and in plane discontinuity – 60 storey. 2.1 MATERIAL PROPERTIES Grade of reinforcing steel: FE 500 Characteristic strength of concrete, fck= 40 MPa Ultimate strain in bending, Ƹcu =l0.0035 2.2 MODEL GEOMETRY Number of storeys = 20. Number of bays along X Direction = 8 Bays, Y Direction = 8 Bays, Storey height = 3.0 meters at Ground Floor, Remaining Floors. Bay width along X Direction = 5 m, Y Direction = 5 m. Similar procedure is used to model with different storey height, that is building with 40 and 60 storey. 2.3 PLAN AND VIEW OF BUILDING Fig-1: Plan View of Building type-1 Fig- 2: 3D View of Type –1
- 3. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 04 Issue: 10 | Oct -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 6.171 | ISO 9001:2008 Certified Journal | Page 951 Fig-3: Plan View of Building type-2 Fig- 4: 3D View of Type –2 Fig-5: Plan View of Building type -3 Fig-6: 3D View of Type –3 3. RESULTS 3.1 MODAL ANALYSIS Chart -1: Mode v/s time period 20 storey Chart -2: Mode v/s time period 40 storey
- 4. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 04 Issue: 10 | Oct -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 6.171 | ISO 9001:2008 Certified Journal | Page 952 Chart-3: Mode V/s Time period 60 Storey 3.2 EQUIVALENT STATIC ANALYSIS 3.2.1 STOREY SHEAR Chart-4: Storey shear– 20 Storey Chart-5: Storey shear– 40 Storey Chart-6: Storey shear– 60 Storey 3.3 STOREY DISPLACEMENTS Chart-7: Storey v/s Displacements – 20 Storey Chart-8: Storey v/s Displacements – 40 Storey
- 5. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 04 Issue: 10 | Oct -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 6.171 | ISO 9001:2008 Certified Journal | Page 953 Chart-9: Storey v/s Displacements – 60 Storey 3.4 STOREY DRIFTS Chart-10: Storey v/s Drifts –20 Storey Chart-11: Storey vs. Drifts – 40 Storey Chart-12: Storey v/s Drifts –60 Storey 3.5 TIME HISTORY ANALYSIS The modal analysis resolves that,shearwall system lessens the time period there by rises the frequency of the building, this is due of the presence of shear wall which inturn increases the stiffness Increase in storey height time period, storey displacements, storey drifts and base forces has increased considerably. Existence of in-plane discontinuity in lateral resisting shear wall systems has a smaller amount of influence on time period and storey shears. Presence of in-planediscontinuityshear wall,storey displacement and drifts has reduced related to RC frame and RC frame with shear wall. Henceforth from the analysis it is accomplished that, in-plane discontinuity in structural systems is endorsed Chart-13: Time history response - Base Force 4. CONCLUSIONS
- 6. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 04 Issue: 10 | Oct -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 6.171 | ISO 9001:2008 Certified Journal | Page 954 where shear wall cannot be arranged for from the foundation level. Considerable increase in columnandbeamforcesin shear wall and in-plane discontinuity structures. The time history analysis results infers that, Reinforced concrete frame with in-plane discontinuity structure displays enhanced performance in decreasing the peak displacement up to 40 storey, above 40 storey RC frame with shear wall systems improved performanceinfalling the peak displacements. Hereafter it can be determined that, above 40 storey, in-plane discontinuity structure will have a lesser amountof stability compared to shear wall structures. 5. REFERENCES [1]. Sarkar P, Prasad A Meher, Menon Devdas, “Vertical geometric irregularity in stepped building frames ”, ,Engineering Structures 32, (2010) , page no.2175–2182. [2]. Karavallis, Bazeos and Beskos, “Estimation of seismic inelastic deformation demands in plane steel MRF with vertical mass irregularities ”,Engineering Structures 30, (2008), page no. 3265–3275. [3]. ChintanapakdeeC.andChopra A.K.,“Seismic Responseof Vertically Irregular Frames: Response History and Modal Pushover Analyses”, Journal of Structural Engineering, ASCE, Vol. 130, (2004), issue 8, page no. 1177-1185. 4]. Das, S. and Nau, J.M, “Seismic Design Aspects of Vertically Irregular Reinforced Concrete Buildings”,Earthquake Spectra, Vol. 19, (2003), No. 3, page no. 455-477. [5].Fragiadakis, M., Vamvatsikos, D. and Papadrakakis, M, “Evaluation of the Influence of Vertical Irregularities on the Seismic Performance of a Nine-Storey Steel Frame”, Earthquake Engineering & Structural Dynamics, Vol. 35, (2006) ,No. 12, page no. 1489-1509. [6].Ruiz, S.E. and Diederich, R, “The Mexico Earthquake of September 19, 1985 – The Seismic PerformanceofBuildings with Weak First Storey”, Earthquake Spectra, Vol. 5, (1989), No. 1, page no. 89-102.