Analysis of Various Thicknesses of Shear Wall with Opening and without Opening and their Percentage Reinforcement

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1 Analysis of Various Thicknesses of Shear Wall with Opening and without Opening and their Percentage Reinforcement S.H.Jagadale *, Post Graduate Student Civil Engineering Department, Dr.D.Y.Patil School of Engg and Tech, Charholi(Bk) Pune-42,India. N.L. Shelke Asst. Professor, Civil Engineering Department, Dr.D.Y.Patil School of Engg and Tech, Charholi(Bk) Pune-42,India. Abstract: Due to increase in population spacing in India is needed, especially in urban areas. Structural engineers in the seismic regions across the world often face the pre ssure to de sign high rise buildings with stiffne ss irregularities, even though they know the se buildings are vulnerable under seismic loading. Today s tall buildings are becoming more and more slender, leading to the possibility of more sway in comparison with earlier high rise buildings. Improving the structural systems of tall buildings can control their dynamic re sponse. With more appropriate structural forms such as shear walls and improved material properties. Lateral force s of wind and earthquake are usually resisted by shear walls which are parallel to the direction of lateral load. These shear walls, by their shearing resistance and resistance to overturning, transfer the lateral loads to the foundation. In the seismic design of buildings, reinforced concrete structural walls, or shear walls, act as major earthquake resisting members. The properties of the se seismic shear walls dominate the response of the buildings, and therefore, it is important to evaluate the seismic re sponse of the walls appropriately. A shear wall may contain many openings due to the functional requirements such as doors and windows, which may largely affect the overall seismic re sponse of the structure. An earthquake load is applied to a building of ten stories located in zone V. In this pre sent study, main focus is to determine effectiveness of shear wall with various thickne sse s, and al so vertical opening, staggered opening and without opening has been studied with the help of different models and also analysis and observe the behaviour of shear wall with and without openings in shear wall under seismic loads. Keywords: Shear Wall, Response spectrum Method, Base, Shear, Time Period.. INTRODUCTION.. General Information I n modern high rise buildings, shear walls are generally used as a vertical structural element for resisting the lateral loads that is induced by the effect of wind and earthquakes, they will have the strength and stiffness to resist the horizontal forces. Lateral forces caused by wind, earthquake, and uneven settlement loads, in addition to the weight of structure and occupants; create powerful twisting (torsion) forces. These forces can literally tear (shear) a building apart. Reinforcing a frame by attaching or placing a rigid wall inside it maintains the shape of the frame and * Corresponding Author prevents rotation at the joints. Shear walls not only help to prevent catastrophic collapse, but they also help to prevent small-scale damage like cracked drywall and fractured tile. Shear walls play the same role in houses in high-wind zones. No matter the source of the force exerted on a house atmospheric or tectonic shear walls are simply designed to protect the home and its occupants. Finite Element modeling now days is an essential approach in analyzing and simulating civil engineering problem numerically. Shear walls are generally located at the sides of buildings or arranged in the form of core

2 that houses stairs and lifts. Shear walls in a building is a structurally efficient solution to stiffen the building because they provide the necessary lateral strength and stiffness to resist horizontal forces.. They are generally provided along both length and width of the building and are located at the exterior, interior sides of the buildings. Shear walls are vertical structural elements for resisting the lateral loads that may be induced by the effect of wind and earthquakes acting on tall structure. To reduce the effect of earthquake reinforced concrete shear walls are used in the building. These can be used for improving seismic response of buildings. The provision of shear wall in building to achieve rigidity has been found effective and economical. Shear walls are usually used in tall building to avoid collapse of buildings. When shear wall are situated in advantageous positions, they can form an efficient lateral force resisting system. Shear walls may have one or more openings for functional reasons such as doors, windows, and other types of openings in shear wall. The size and location of openings may vary depending on purposes of the openings. The size and location of shear walls is extremely critical. Properly designed and detailed buildings with shear walls have shown good performance in past earthquakes. Shear walls also provide lateral stiffness to prevent the roof or floor above from excessive side-sway. When shear walls are stiff enough, they will prevent floor and roof framing members from moving off their supports. Also, buildings that are sufficiently stiff will usually suffer less non-structural damage. When shear walls are strong enough, then capable of transferring lateral forces from walls to next element as a path- floors, roofs to the ground foundation in a direction parallel to their planes a shear walls, floors, foundation walls, footings. Shear walls in high seismic regions require special detailing. However, in past earthquakes, even buildings with sufficient amount of walls that were not specially detailed for seismic performance (but had enough well distributed reinforcement) were saved from collapse. Shear wall buildings are a popular choice in many earthquake prone countries, like Chile, New Zealand and USA. Shear walls are easy to construct, because reinforcement detailing of walls is relatively straightforward and therefore easily implemented at site. Shear walls are efficient, both in terms of construction cost and effectiveness in minimizing earthquake damage in structural and nonstructural elements (like glass windows and building contents). For this study residential type of structure, with G+ building are considered which one of the frame, with or without opening in shear wall and also find out their percentage reinforcement by using finite element software (ETABS) under earthquake loads..2 Aim & Objectives of Study Analysis shear wall, with or without opening and staggered opening of various thicknesses. Objectives of study:-. To study the Performance of the building with opening or without opening in shear wall having varying thickness. 2. To study the behaviour of vertical opening or staggered opening in shear wall having varying thickness.. To study, which thickness of shear walls is give best result under the action of lateral loads. 4. To determine the percentage of reinforcement in shear wall under the action of lateral loads in buildings with help of comparison. Fig.: Concept of with and without opening in shear wall 2. MODELLING AND ANALYSIS In this Project, the model was meshed in order to obtain results with higher accuracy. The

3 earthquake load and load combinations were applied as per IS and the seismic analysis was done by response spectrum method. In this study, zone given V because in that area earthquake occure more time and also their frequency is more. The results obtained are compared for the displacement and base shear at different storey levels 2. Location of Shear Wall When shear wall are situated in advantageous positions, they can form an efficient lateral force resisting system. They are generally provided along both length and width of the building and are located at the exterior, interior sides of the buildings. Shear wall located as a symmetrically to reduce effects of twist. Symmetry can be along one or both the direction. Shear walls in both directions, which is a more realistic situation because both wind and earthquake forces need to be resisted in both directions. Model Staggered opening in shear wall structure mm thicknesses:- Model 4 Without opening in shear wall structure Model Vertical opening in shear wall structure Model 6 Staggered opening in shear wall structure Figure 2 and Figure show Grid-Plan of RCC building and elevation of building respectively. Some shear wall are used for Lift wall and they are situated in interior of structure. These shear walls are not providing a opening Preliminary data required for analysis Fig.2: Grid Plan for RCC layout 2.2. Plan of the building model are given below 2 mm thicknesses:- Model Without opening in shear wall structure Model 2 Vertical opening in shear wall structure Fig.: Elevational Plan for RCC structure Code of Practice Number of codes are used for design and analysis of RCC structure, but in that study, refer a following IS codes- IS 46-2-Plain and Reinforced Concrete. IS 87 Parts-I -Code of Practice for Design Dead

4 Loads For Buildings and Structures Shear Wall Thickness 2mm, mm IS 87 Parts-I I-Code of Practice for Design Live Loads For Buildings and Structures. 4 Size of column mm x 6 mm IS 87 Parts-III -Code of Practice for Design Wind Loads For Buildings and Structures Size of beam mm x 6 mm IS (Criteria for Earthquake Resistant Design Of Structures) 6 Depth of slab mm IS 92:99 Ductile Detailing of Reinforced Concrete structures Preliminary data are required foe seismic analysis are as follows in a tabular form. Table : Preliminary geometrical data required for analysis Sr.No. Parameter Values 7 Opening of Shear Wall.8m X 2.4m,.2m X.2m.9m X.2m Table : Preliminary load consideration data required for analysis Typical Floor Plan Dimension 22.7m X 8.2 Sr. No. Parameter Values 2 Number of Story G+ Floor height Dead Load As per structure Ground Floor Typical Floor.m.m 2 Impoed Load 2KN/m 4 Infill wall mm thick Typical Table 2: Preliminary structural data required for analysis Floor Finish Floor-KN/m, Terrace Floor- Sr. No. Parameter Values KN/m Type of structure Special RC moment resisting frame 4 Water Proofing Balcony-KN/m, Toilet- 4 KN/m 2 Materials Concrete Grade Reinforcement Grade M2 Fe 6 Specific weight of concrete Specific weight of Infill Wall 2 KN/m 2 KN/m

5 Table 4: Seismic data required for analysis [As pe IS 89:22 (part-i)] Sr. No Parameter Values Seismic zone V 2 Zone factor (Z).6 Type of soil Medium 4 Damping % Response reduction factor (R). ( For Importance factor Residential 6 (I) Building) lateral forces at all levels above the story under consideration. The base shear is found to be much lesser for shear wall with staggered openings when compared to shear wall with vertical openings. As the base shear is reduced, the shear wall with staggered openings will be less susceptible to damage. However, the base shear depends upon the existing soil condition at the site Time Period OBSERVATION AND RESULT..Time Period For seismic analysis, the first mode or the fundamental time period is the most significant, which is the inherent property of the building. The time period obtained from the analysis for all three models is shown in figure. It can be seen that the staggered openings exhibited a higher value of time period when compared to vertical openings, and without opening in shear wall time period is less as compare to with opening in wall, which indicates that the shear wall with staggered openings can perform better during seismic action than the vertical openings and without opening in wall. These results are comparatively same for thickness of 2mm and mm shear wall. These results are shown as a graphical form Notation:- Mode Fig.4: Mode versus Time Period of 2mm thk shear wall Time Period = Staggered Opening in shear wall = Vertical Opening in Shear Wall =Without opening in shear wall..2 Base Shear Story shear is defined as the sum of design Mode Fig.: Mode versus Time Period of mm thk shear wall Figure shows, without opening in shear wall base shear is more as compared to with opening in shear wall in all storey level.

6 Base Storey 2 Storey 4 Storey 6 Storey 8 Storey Storey 2 Base Storey2 Storey4 Storey6 Storey8 Storey Storey2 Acknowledgements Base Shear I express my profound gratitude to our project guide Dr. Nagesh L. Shelke for their inspiring guidance due to which our difficulties and questions were shaped into the development of this project and complete support, co-operation and valuable suggestions. I would like to thank Principal, Dr. Ashok S. Kasnale and H.O.D, Dr. Sanjay K. Kulkarni of Civil Department, who were the source of inspiration throughout the making of this project stage I and helped us to accomplish our goals in a much easier and healthy Story No. References Base Shear Fig.6: Storey versus Ba se Shear in X Direction of 2mm thk. Shear Wall Story No. Fig.7: Storey versus Ba se Shear in X Direction of 2mm thk. Shear Wall Notations: = Without Opening in shear wall = Vertical Opening in Shear Wall = Staggered opening in shear wall 4. CONCLUSION Performance of staggered opening is a best in a seismic zone as compared to vertical opening and without opening in shear wall. Shear base is less for a staggered opening in shear wall. The base shear of without opening is more as compare to opening in shear wall and also observe that the time period is more with comparision of vertical opening and without opening in shear wall [] Mosoarca Marius, Seismic behavior of reinforced concrete shear walls with regular and staggered openings after strong earthquakes between 29 and 2, Engineering Failure Analysis, Vol. 4, pp. 7 6, 2. [2] Mazen A. Musmar-Analysis of Shear Wall with Openings Using Solid6 Element, Jordan Journal of Civil Engineering, Volume 7, No. 2, 2 [] Sharmin Reza Chowdhury, M.A. Rahman, M.J. Islam and A.K. Das, Effects of openings in shear wall on seismic response of structures, IJCA, Vol. 9, No., pp., Dec. 22. [4] Anshuman S, Dipendu Bhunia, Bhavin Ramjiyani, solution of shear wall location in multi storied building, international journal of civil and structural engineering, 2. [] O. Esmaili et al. Study of Structural RC Shear Wall System in a 6-Story RC Tall Building, The 4th World Conference on Earthquake Engineering October 2-7, 28, Beijing, China [6] H-S. Kim, D.-G. Lee Analysis of shear wall with openings using super elements Engineering Structuers 2(2) [7] Yanez F.V., R. Park and T. Paulay, Seismic behavior of walls with irregular openings, in Proc. Tenth world conference on Earthquake Engineering, Rotterdam, 992. [8] Aejaz Ali and James K. Wight, R.C. structural walls with staggered door openings, Journal of Structural Engineering, Vol. 7, No., pp. 4, May. 99.

7 [9] Husain, MA, 2. Analysis of Shear Wall with Openings using Brick Element, European Journal of Scientific Research, ISSN 4-26X, Vol., No., pp [8] Kim HS. and Lee DG. 2. Analysis of shear wall with openings using super elements, Engineering Structures, 2: [] Lin C.Y. and C.L. Kuo, Behavior of shear wall with openings, in Proc. Ninth world conference on Earthquake Engineering, Japan, 988, paper, p. 4. [] Anuj Chandiwala, Earthquake Analysis of Building Configuration with Different Position of Shear Wall, International Journal of Emerging Technology and Advanced Engineering ISSN , ISO 9:28 Certified Journal, Volume 2, Issue 2, December 22, Adhoc Lecturer in Sarvajanik College of Engineering & Technology, Athvalines, Surat, Gujarat, India. [2] Balkaya C. and Kalkan E. Estimation of fundamental periods of shear-wall dominant building structures, Earthquake Engineering and Structural. Dynamics. 2; 2: [] Pankaj Agarwal and Manish Shrikhande Earthquake Resistant Design of Structures PHI Learning Private Limited, New Delhi.