IRJET- Seismic Analysis for Vertically Geometric Irregularity using E-Tabs
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This document analyzes the seismic response of a vertically geometrically irregular G+5 building located in seismic zones II, III, and IV using ETABS software. The building is modeled and analyzed according to Indian code IS1893:2002. Results for base shear, displacement, drift, and storey shear in both x and y directions are presented for each zone. Base shear, displacement, drift, and storey shear all increase with increasing zone intensity from II to III to IV as expected. The analysis provides important information about the effects of vertical geometric irregularity on seismic response in different zones.
IRJET- Seismic Analysis for Vertically Geometric Irregularity using E-Tabs
- 1. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 03 | Mar 2019 www.irjet.net p-ISSN: 2395-0072 © 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 7369 SEISMIC ANALYSIS FOR VERTICALLY GEOMETRIC IRREGULARITY USING E-TABS K. Vamsi Krishna 1, k. Naga Poojitha 2, L. Mohan Kumar 3, K. Krishna Mohan 4, R. Leela krishna sai 5 ,P. Girish sai kumar6 1Assistant professor in Civil Engineering, Dhanekula institute of engineering& Technology, Ganguru, Andhra Pradesh. 2, 3,4,5,6 students in civil engineering, D.I.E.T, Ganguru, Andhra Pradesh. ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - During an earthquake, failure of structurestarts from the points of weakness. This type of weakness arises due to discontinuity in mass, stiffness and geometry of structure. Vertically irregular structure isnothingbutthediscontinuities in the vertical plane of the structures. To construct any structure safety plays a very important role, in that a building must resist for earthquake. For a regular or for a simple structure damage due to earthquake will be minimum but irregularity makes structures vulnerable under seismic loading. In this present study G+5 building located in zone II, III, IV are analyzed using ETABS software for vertical geometric irregularity. In order to find out the seismic response of the structure for in three different zones, it is important to obtain the plan of the structure and to analyze various elements of a building such as beam, column, slab, foundation and stair case under the seismic load actingonthe structure. The structure was analyzed with various combination as per code IS1893:2002 part-1. Wealsousedthe AUTOCAD for our designs of the structures. The main advantage of displacing the drawing in AutoCAD is user has more flexibility to modify the drawings in AutoCAD. KEYWORDS: seismic load, G+5,Zones, AutoCAD,E-TABS. 1.INTRODUCTION Earthquakes are natural hazards, Generally earthquakesare mainly caused by the collision of tectonic plates, someother natural disasters like volcanic eruptions and other man- made structures. For new constructions, establishing earthquake resistant regulations and their implementation experience is the critical safeguard against earthquake induced damage. when constructing an vertically irregular structures the structural engineers role becomes more difficult than others. Before wegoingtoconstructa structure evaluation is important. The analysis and design is mustand should for every irregular structures, that gives the result whether the structure is safe or not. In the shape point of view, The buildings can are broadly categorized as regular and irregular buildings. The irregularity of a building can be depends on the stiffness, discontinuity in plane or geometry, mass or load resisting elements. The structural irregularities can be broadly categorized as horizontal and vertical irregularity. The different factor that causes damage to the structure throughout the earthquake are mass irregularity, vertical irregularities, torsional irregularity, irregularity in strength and stiffness, etc. Generally in multi-storied RC framed buildings, The destruction stats from the point of weakness. In some of the cases, theseweaknessesarealsodevelopedby discontinuities in stiffness, strength or mass between adjacent stories. 1.1 Necessity of the study Seismic analysis of a building has now become an important part in present senario of modern structural designs, it is because earthquake causes lots of damages and loss of life. Multi-storey structures constructed by reinforced cement concrete are subjected to severe actions of seismic waves during earthquake. The main reason for the failure of RC building is irregularity in geometry. The irregularities may be in its plan dimension, lateral force distribution. 2. METHODOLOGY Following steps of methods are adopted in this project: Step-1: Selection of the structure and three different seismic zones like II, III, IV. Step-2: Collection and study of literatures Step-3: Plan representation in CAD software Step-4: Export to ETABS Step-5: Assigning of loads and load combinations Step-6: Seismic analysis and design for the data model Step-7: Interpretation of results.
- 2. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 03 | Mar 2019 www.irjet.net p-ISSN: 2395-0072 © 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 7370 Table -1: S. No Content Description 1 Type of structure Vertical geometric irregularity 2 Shape of the building Asymmetrica l 3 Number of storey G+5 4 Height of the floor 3.0m 5 Materials Concrete (M25), Steel(Fe415) 6 Wall thickness 300mm 7 Beam size 230*450mm 8 Column size 300*550mm 9 Depth of slab 150mm 10 unit weight of RCC 25kN/m3 11 Live load 3.0kN/m2 Model considered in the project Fig -1: G+5 Vertical Geometric Irregularity 3. RESULTS Results for base shear, displacement and drift on both Xand Y directions are represented graphically for three different zones Table-1 Base shear along x-direction in three different zones: No of Stories Zone 2 Zone 3 Zone 4 5 344.342 550.9472 826.4209 4 298.7901 478.0642 717.0962 3 266.728 426.7648 640.1471 2 139.494 223.1904 334.7856 1 39.8936 63.8298 95.7447 Ground 0.4885 0.7816 1.1724 Base 0 0 0 Table-2 Base shear along y-direction in three different zones: No of stories Zone 2 Zone 3 Zone 4 5 344.342 550.9472 826.4209 4 298.7901 478.0642 717.0962 3 266.728 426.7648 640.1471 2 139.494 223.1904 334.7856 1 39.8936 63.8298 95.7447 Ground Ground 0.4885 0.7816 1.1724 Base Base Base 0 0 0 GRAPH-1,2 BASE SHEAR IN BOTH X & Y DIRECTIONS FOR THREE ZONES
- 3. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 03 | Mar 2019 www.irjet.net p-ISSN: 2395-0072 © 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 7371 Table-3 Displacement along x-direction for three different zones: No of Stories Zone 2 Zone 3 Zone 4 5 0.001 0.001 0.002 4 0.001 0.001 0.002 3 0.000449 0.001 0.001 2 0.000296 0.000474 0.001 1 0.000144 0.000231 0.0003459 Ground 1.54E-05 2.46E-05 3.69E-05 Base 0 0 0 Table-4 Displacement along y-direction for three different zones: No Of Stories Zone 2 Zone 3 Zone 4 5 0.001 0.001 0.002 4 0.001 0.001 0.002 3 0.001 0.001 0.001 2 0.000348 0.001 0.001 1 0.000165 0.000263 0.000395 Ground 1.69E-05 2.71E-05 4.07E-05 Base 0 0 0 GRAPH-3,4 STOREY DRIFT IN BOTH X&Y DIRECTIONS FOR THREE ZONES Table-5 Storey Shear in zone II: No. of stories Elevati on Locatio n x- directio n (mm) y- directio n (mm) Storey 5 15.45 Top -344.342 -344.342 15.45 Bottom -344.342 -344.342 Storey 4 12.45 Top -643.132 -643.132 12.45 Bottom -643.132 -643.132 Storey 3 9.45 Top -909.86 -909.86 9.45 Bottom -909.86 -909.86 Storey 2 6.45 Top -1049.35 -1049.35 6.45 Bottom -1049.35 -1049.35 Storey 1 3.45 Top -1089.25 -1089.25 3.45 Bottom -1089.25 -1089.25 Ground 0.45 Top -1089.74 -1089.74 0.45 Bottom -1089.74 -1089.74 Base 0 Top 0 0 0 Bottom 0 0 Table-6 Storey Shear in zone III: No. of stories Elevati on Locatio n x- directio n (mm) y- directio n (mm) Storey 5 15.45 Top -550.947 -550.947 15.45 Bottom -550.947 -550.947 Storey 4 12.45 Top -1029.01 -1029.01 12.45 Bottom -1029.01 -1029.01 Storey 3 9.45 Top -1455.78 -1455.78 9.45 Bottom -1455.78 -1455.78 Storey 2 6.45 Top -1678.97 -1678.97 6.45 Bottom -1678.97 -1678.97 Storey 1 3.45 Top -1742.8 -1742.8 3.45 Bottom -1742.8 -1742.8 Ground 0.45 Top -1743.58 -1743.58 0.45 Bottom -1743.58 -1743.58 Base 0 Top 0 0 0 Bottom 0 0
- 4. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 03 | Mar 2019 www.irjet.net p-ISSN: 2395-0072 © 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 7372 Table-7 Storey Shear in zone IV: No. of stories Elevati on Locatio n x- directio n (mm) y- directio n (mm) Storey 5 15.45 Top -826.421 -826.421 15.45 Bottom -826.421 -826.421 Storey 4 12.45 Top -1543.52 -1543.52 12.45 Bottom -1543.52 -1543.52 Storey 3 9.45 Top -2183.66 -2183.66 9.45 Bottom -2183.66 -2183.66 Storey 2 6.45 Top -2518.45 -2518.45 6.45 Bottom -2518.45 -2518.45 Storey 1 3.45 Top -2614.19 -2614.19 3.45 Bottom -2614.19 -2614.19 Ground 0.45 Top -2615.37 -2615.37 0.45 Bottom -2615.37 -2615.37 Base 0 Top 0 0 0 Bottom 0 0 GRAPH-5,6 FOR STOREY SHEAR AT THREE DIFFERENT ZONES ALONG X-DIRECTION AND Y-DIRECTION 4. CONCLUSIONS • In this study, we have mainly considered storey displacement, storey drift,Axial lateral loadandStoreyshear for the building and analysed by using E-tabs as per the specification IS 1893:2002(part1). • It can be concluded that, Base shear, storey displacement, storey shear and storey drift will increasesastheearthquake intensity increases from zone II, zone III, zone IV. 6.REFERENCES 1. shaikh A. Aijaj, G.S. Deshmukh, ‘’Seismic analysis of vertically irregular building’’ (ISSN:2277-8594), July 2016. 2. Kusuma B, “seismic analysis of a high-rise framed structure with irregularities”, vol 4 issue-7,July 2017. 3.Akhilesh rathi, Dr. Ashwin Raut, “Design and analysis of regular and vertical irregular building by using E- TABS”, (ISSN NO:2249-7455). 4. Devesh P. soni and bhartha B. mistry ." Qualitative review of seismic response of vertically irregilar building Frames ". ISET Journal of Earthquake Technology, Vol43, No.4, December 2006, PP 121- 132. 5. Ilham Salehi, Dr. Raman Nateriya, “seismic evaluation of vertical irregular building with setback”, vol5 issue-6,June 2018. 6. Rahul, Shivanand C G, “Study of vertical irregularity of tall rc structure under lateral load”, vol4 issue-8, august 2017. 7. Lakshmi Subash, “seismic behaviour of vertically irregular reinforced concrete buildings with p-delta effect”, vol4 issue-4, April 2017. 8. Dileshwar Rana, Prof. juned Raheem, “seismic analysis of regular & vertical geometric irregular RCC framed building”, vol2 issue-4,July 2015. 9. Poonam, Anil kumar and Ashok K.Gupta "Study of response of stucturally irregular buildimng frames to seismic excitation ". 10.Ankit Purohit, Lovishpamecha, “seismic analysis of G+12 multistory building varying zone and soil type, vol4 issue-6, June 2017. 11. Himanshu Bansal, Gagandeep,“seismicanalysisand design of vertically irregular RC building frames”, (ISSN:2319-7064). 12. Vikas joshi, “Dynamic analysis of vertical varying irregular building with response spectrum”,vol8issue- 1, January 2018. 13.Anil kumar S Katageri, Sharanabasava G, “seismic performance study of R.C. buildings having vertical geometric irregularity using pushover analysis”, vol3 issue-11, 2016.