DYNAMIC RESPONSE OF MULTISTORIED BUILDING WITH AND WITHOUT IN-FILL WALLS

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1 International Journal of Civil Engineering and Technology (IJCIET) Volume 9, Issue 12, December 2018, pp , Article ID: IJCIET_09_ Available online at aeme.com/ijciet/issues.asp?jtype=ijciet&vtype= =9&IType=12 ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed DYNAMIC RESPONSE OF MULTISTORIED BUILDING WITH AND WITHOUT IN-FILL WALLS Shaik Abdul Sameer M-Tech Scholar, Department of Civil Engineering Kallam Haranadhareddy Institute of Technology, Guntur M. Jugal Kishore, D.V.S.Sankara Reddy Assistant Professor, Department of Civil Engineering, Kallam Haranadhareddy Institute of Technology, Guntur ABSTRACT Generally in all Buildings the entry floor is set as soft storey. If the storey contains lower rigidity Compare to the other Storey than it is known as soft storey due to which it does not contains any infill walls with same properties and parameters as the other storey s has. Due to Unavoidable features the First Storey of Multi Storey Building is kept as soft storey in Many Urban Cities in India today. Mainly to Provide Parking (or) reception lobbies in First Storey Soft storey is being chosen. The other storeys rather than soft storey are provided with brick in filled walls. Usually the R.C.C buildings with masonry Infill s are constructed. The space b/w horizontal and vertical resisting member s of the R.C.C structure is filled with masonry infill s and mostly used for all types of partition, decorative and attractive walls. An analysis and Investigates the Response of multi storey reinforced concrete frame consisting of bare frame, total infill walls and soft storey at different levels in buildings and to interpret the dissimilarities in seismic response with bare and total in filled frame containing some soft storey s at different levels when earthquake forces acts on it. To study the S.F,deflections, axial forces and B.M S in total infill frame with particular soft storey, and see the similarities with the same results of frame without infill s i.e. bare frame.this study is an effort to explore the Dynamic behaviour of the different high rise building with particular soft storey.and also to study the soft storey effect and building and introducing of total infill walls in R.C.C structures for critical load combination s by taking 3d space model of G+12 Storey frame.in this study ETABS and STAAD pro V8I-2008 Software s used for Analysis Purpose. Keywords: Soft Storey, Wall Panels, Masonry Infill, Bare Frame, Earthquake, Axial Forces, Bending Moments, Deflections editor@iaeme.com

2 Shaik Abdul Sameer, M. Jugal Kishore and D.V.S.Sankara Reddy Cite this Article: Shaik Abdul Sameer, M. Jugal Kishore and D.V.S.Sankara Reddy, Dynamic Response of Multistoried Building with and Without In-Fill Walls, International Journal of Civil Engineering and Technology (IJCIET) 9(12), 2018, pp INTRODUCTION A large number of reinforced concrete buildings are constructed with masonry infills. Masonry infill panels have been widely used as interior and exterior partition walls for aesthetic reasons and functional needs. When infill walls are omitted in a particular storey, a soft storey is formed compared to much stiffer other stories. The masonry infill can be modelled by equivalent struts. Normally in structural analysis it is considered that the Equivalent Static Analysis is more conservative against ground shaking for regular structures or structures of smaller height. In this report the behaviour of reinforced concrete (R.C.) frames with brick masonry infill for various parametric changes have been studied to observe their influences in deformation patterns of the frame. The infill components increase the lateral stiffness and serve as a transfer medium of horizontal inertia forces. From this conception the floors that have no infill component has less stiffness regarding other floors. The objectives of this thesis work are as follows: To find out the influence of masonry infill wall panel in Reinforced Concrete framed Structures in terms of deformation. To study the behaviour of frame with brick masonry infill by modelling masonry infill as a diagonal strut. 2. METHOD OF ANALYSIS For this purpose the STAAD Pro V8i software is utilized to create 3D model and carry out the analysis. The buildings are modelled as a series of load resisting elements. The lateral loads to be applied on the buildings are based on the Indian standards. The study is performed for seismic zone IV as per IS 1893:2002. The buildings adopted consist of reinforced concrete and brick masonry elements. The frames are assumed to be firmly fixed at the bottom. In this chapter fifteen (15) different models of G+12 story building are investigated for the 13 load combination as per IS: (part1); these models vary in infill walls distribution. Both the long and the short directions are as such included. The models are described as follows: 1. Model 1: Bare frame (without changing column orientation). 2. Model 2: Bare frame (with changing column orientation). 3. Model 3: Infill walls at all levels (with infill). 4. Model 4: Infill walls at all levels except ground storey (Ground soft storey). 5. Model 5: No infill wall at ground and 1 st floor level (G+1 soft storey). 6. Model 6: No infill wall at ground, 1 st and 2 nd level (G+1, 2 soft storey). 7. Model 7: No infill wall at ground and 3 rd level (G+ 3 soft storeys). 8. Model 8: No infill wall at ground, 3 rd and 4 th level (G+3, 4 soft storey). 9. Model 9: No infill wall at ground, 3 rd, 4 th and 7 th level (G+3, 4, 7 soft storey). 10. Model 10: No infill wall at ground, 3 rd, 4 th, 7 th and 8 th level (G+3, 4, 7, 8 soft storey). 11. Model 11: No infill wall at ground, 3 rd, 6 th, 9 th and 12 th level (G+3, 6, 9, 12soft storey). 12. Model 12: No infill wall at ground and 6 th level (G+ 6 soft storeys) editor@iaeme.com

3 Dynamic Response of Multistoried Building with and Without In-Fill Walls 13. Model 13: No infill wall at ground and 10 th level (G+ 10 soft storeys). 14. Model 14: No infill wall at ground, 10 th and 11 th level (G+10, 11 soft storey). 15. Model 15: No infill wall at ground, 10 th, 11 th and 12 th level (G+10, 11, 12 soft storey). After design of column it is observed that the provided column size (0.6 m x 0.23 m) was not sufficient for the above data. Hence we have increased the size of column (0.8 m x 0.4 m) and also the size of beam is increased (0.4 m x 0.3 m) for safety purpose. A data used for 15 models is same as used in solved problem except the column size which is not sufficient for G+12 storey building as earlier discussed. 3. MODEL DEVELOPMENT Elevation Side View 3D model of G+12 storey building (Without infill) Figure 3.1 (Model 1) Now by changing the orientation of the columns of the bare frame (Model 1) to assess the changes in results. Figure.3.1 shows the plan, elevation, side view and 3D model of the bare frame (Model 2) in which columns are oriented. 3D model of G+12 storey building 3D model of G+12 storey building (With changing column orientation) (With infill as diagonal strut) Figure 3.2 (Model 2) Figures 3.3 (Model 3) editor@iaeme.com

4 Shaik Abdul Sameer, M. Jugal Kishore and D.V.S.Sankara Reddy 4. RESULTS 4.1. Lateral Displacements (Δ) and Story drift The lateral displacements and storey drift of the building for seismic analysis in X-direction and Z-direction are presented. The results are plotted on the graph and compared with the fourteen models. It is observed that the maximum lateral displacements are reduced due to the presence of infill as compared to bare frame. It is also observed that the displacement is increased in model 1 in the X-direction and decreased in the Z-direction because of the change in column orientation. As per IS: (part1) the storey drift in any storey due to the minimum specified design lateral force, with partial load factor of 1.0 shall not exceed times the storey height. Hence the maximum story drift for these models will be 1.2 cm. The story drift results are plotted on the graph and compared with the fourteen models. It is observed that the maximum story drift is occurred in the bare frame (Model 1 and Model 2) and the story drift is reduced in other Models as compared to Model 1 and 2 due to the presence of infill. Figure Displacement of various models in X-direction editor@iaeme.com

5 Dynamic Response of Multistoried Building with and Without In-Fill Walls Figure Displacement of various models in Z-direction Figure Story drifts of various models in X-direction

6 Shaik Abdul Sameer, M. Jugal Kishore and D.V.S.Sankara Reddy Figure Story drifts of various models in Z-direction 4.2. Maximum Forces and Bending Moments in Columns: The maximum axial, shear forces and bending moments in columns of the all fourteen models for the 13 load combinations for seismic analysis. The results are plotted on the graph and compared with the fourteen models. It is observed that the infill decrease the bending moments and shear forces in columns they increase the axial compression in the columns to which they are connected Figure Maximum Axial force in column of various models

7 Dynamic Response of Multistoried Building with and Without In-Fill Walls Figure Maximum bending moment in column of various models Figure Maximum Shear force in column of various models

8 Shaik Abdul Sameer, M. Jugal Kishore and D.V.S.Sankara Reddy 4.3. Comparison of results for Maximum displacements The maximum displacement in X-direction and Z-direction for all fifteen models for 13 load combination as per IS: (part1) for seismic analysis. The results are plotted on the graph and compared with the fourteen models. It is observed that the infill decrease the bending moments and shear forces in columns they increase the axial compression in the columns to which they are connected. The variation of displacements and the percentage reduction in displacement for the model with infill in comparison to that of model with bare frame is presented. It is observed that the percentage reduction for model 3 is to be shown % and % in X-direction and Z-direction respectively as compared to bare frame (model 1). Figure Maximum Displacement in X and Z-direction in various models 4.4. Comparison of forces and moments for Corner and Middle column The Maximum forces and moments are shown in graphical representations for corner column and middle column. Figure 6.16 shows the position of corner column and middle column. From the graph it is observed that the maximum axial forces are induced only in corner column as compared to middle column whereas maximum moment and shear forces are induced in middle column as compared to corner column editor@iaeme.com

9 Dynamic Response of Multistoried Building with and Without In-Fill Walls Figure Maximum Axial forces in corner and middle column for various models Figure Maximum Bending Moment in corner and middle column for various models

10 Shaik Abdul Sameer, M. Jugal Kishore and D.V.S.Sankara Reddy Figure Maximum Shear Force in corner and middle column for various models 5. CONCLUSIONS The present study is an attempt to explore the dynamic behaviour of the high rise building with some soft storey. Also to study the effect of soft storey and introduction of infill wall in building for critical load combination with the help of three dimensional space model of G+12 storey building. In this study Etabs and STAAD-Pro V8i software are used for analysis and the following conclusions are drawn. RC frame buildings with soft storeys are known to perform poorly during in strong earthquake shaking. For a building that is not provided any lateral load resistance component such as infill wall, the strength is consider very weak and easily fail during earthquake. The horizontal movements of building which has maximum infill wall are much reduced during earthquake compare with other models. So it shows that the presence of infill wall is effectively reduced effect of soft story on structure response in earthquake excitation. The introduction of infill walls in the first storey (model 3) reduces the force in the first storey columns. Due to Present of infill walls (Model-3) it is observed that Minimum Displacements, Storey Drift, BM & SF in X-Z Direction and due to absent of infill walls (Model-1&2) it is observed that Maximum Displacements, Storey Drift, BM & SF in X-Z Direction. The drift and the strength demands in the first storey columns are very large for buildings with soft ground storeys. The displacement and drift is more in building having consecutive soft storeys as compared to other buildings with soft storey. Max Axial forces are seen in Model-4 due to present of Soft Storey at Ground Floor and Min in Model-11 due to Present of Soft Storey at G, 3, 6,9,12 levels and max Axial Forces in corner and middle column is seen in Model-4 due to present of Soft Storey at ground level editor@iaeme.com

11 Dynamic Response of Multistoried Building with and Without In-Fill Walls Max BM in corner and middle column is seen in Model-2 Due to absent of Infill Walls and Min in Model-3 Due to present of Infill Walls. The open first storey is an important functional requirement of almost all the urban multistorey buildings, and hence, cannot be eliminated. Alternative measures need to be adopted for this specific situation. The results of the analysis indicate that an abrupt change in storey stiffness is responsible for the sudden change in displacement, hence placing a greater strength demand on the first story columns. REFERENCES [1] Agrawal P. and Shrikhande M. (2008). Earthquake Resistant Design of Structures. Prentice-Hall of India Pvt. Ltd: Sixth edition, New Delhi. [2] Arlekar,J.N., Jain S.K. and Murty C.V.R.(1997). Seismic Response of RC Frame Buildings with Soft First Storeys. Proceedings of the CBRI Golden Jubilee Conference on Natural Hazards in Urban Habitat, New Delhi. [3] Duggal S.K. (2007). Earthquake Resistant Design of Structures Oxford University Press: First edition, New Delhi. [4] Dolsek M. and Fajfar P. (2008). The effect of masonry infills on the seismic response of a four storey reinforced concrete frame-a deterministic assessment. Engineering Structures, 30, [5] Hejazi F., Jilani S., Noorzaei J., Chieng C.Y., Jaafar M.S. and Abang A.A (2011). Effect of Soft Story on Structural Response of High Rise Buildings. IOP Conf. Series: Materials Science and Engineering, 17. [6] Helou S. and Abdul R. T. (2008). Dynamic Behavior of Reinforced Concrete Structures with Masonry Walls. An - Najah Univ. J. Res. (N. Sc.) Vol. 22. [7] IS: 1893 (Part 1): Criteria for Earthquake Resistant Design of Structures. Bureau of Indian Standards, New Delhi. [8] IS: 456 (2000). Indian Standard Code of Practice for Plain and Reinforced. Indian Standard Institution, New Delhi. [9] IS: 13920:1993( ). Ductile detailing of reinforced concrete structures subjected to seismic forces-code of practice. Bureau of Indian Standards, New Delhi. [10] Jain S.K. and Murty C.V.R. Proposed draft provisions and commentary on Indian seismic code IS 1893(part 1). Department Of Civil Engineering, IIT Kanpur. [11] Madabhushi S. P. G. and Lawson C. H. (2006). Centrifuge modelling-based verification of response spectra design methods for some vulnerable structures. Geotechnical and Geological Engineering 24: [12] Sharany H. and Khan M. A. (2008). Seismic Vulnerability of Columns of RC Framed Buildings with Soft Ground Floor. International Journal of Mathematical Models and Methods in Applied Sciences vol.2. [13] SP 16: Design Aids for Reinforced Concrete to IS: Bureau of Indian Standards, New Delhi. [14] Vahidi E.K. and Malekabadi M.M. (2009). Conceptual Investigation of Short-Columns and Masonary Infill Frames Effect in the Earthquakes. World Academy of Science, Engineering and Technology 59. [15] Viswanath K.G., Prkash K.B. and Desai A. (2010). Seismic Analysis of Steel Braced Reinforced Concrete Frames. International Journal of Civil and Structural Engineering, Vol.1 No editor@iaeme.com