Non-Linear Analysis of Asymmetric Shear Wall with Openings

Non-Linear Analysis of Asymmetric Shear Wall with Openings

Saleem Malik Yarnal

Department of Civil Engineering BLDEASV.P Dr P.G.Halakatti College of Engg and Tech

Vijayapur, India

Sagar S Allagi

Department of Civil Engineering BLDEASV.P Dr P.G. Halakatti College of Engg and Tech

Vijayapur, India

Prashant M Topalakatti

Department of Civil Engineering BLDEASV.P Dr P.G.Halakatti College of Engg and Tech

Vijayapur, India

Arif Ahmed Mulla

Department of Civil Engineering

BLDEASV. P Dr P.G.Halakatti College of Engg and Tech Vijayapur, India

Abstract Shear walls are one of the excellent means for providing lateral load resistance to high reinforced (RC) buildings. The contribution of shear wall is significant in increasing the stiffness of structure, especially, in Non-linear analysis because shear walls contribute considerable in lateral load resisting system. There are several types of analyses methods available for analyzing shear walls of the building structures. Analysis of structure consists of uniformly distributed lateral loading, triangularly distributed lateral loading with a maximum value at the top.

In this work seismic analysis of shear wall building in zone III is done and study for shear walls with various percentages of openings is done. Such as mode shape, fundamental frequency base shear, drift, shear force, stiffness. The performance of shear wall is compared with various percentages of openings of shear wall area. In this project the software, ETABS 2013 is used for the analysis of the structure.

Keywords Shear Wall, Non-Linear Static Analysis, Asymmetrical, Performance Point, Spectral Accelerations, And Base Shear

1. INTRODUCTION

   The aim of this paper is to investigate the influence non- linear static behavior of asymmetric shear wall and comparison of the result using E-TABS 2013 software.

   Special attention is paid to:

   1. The behavior of asymmetric plan in shear wall system.

   2. The implications of openings in shear wall with 10%, 20%, 30% and 40% openings and without openings. The building is located in North Karnataka zone III, India.

2. IDEALIZATION OF THE SYSTEM

   1. Structural Idealization

      A twelve-storey public buildings located in zone 3 as per Indian code is considered. The building models having shear wall and without shear walls are modeled, and with

      different percentages of openings. the column 300 x 900 mm, dimensions of beam 230x 500 mm the thickness of slab is 120mm and thickness of wall is 230mm.

   2. Idealization behavior of model

   The function of the shear wall is to resist the lateral loads in the system. During earthquake, a rigid base may be subjected to displacement in six degrees of freedom, and the resistance of soil may be expressed by the six corresponding resultant force components. Hence the structural behavior of the elastic half space is presented completely by a set of force displacement relationships defined for these degrees of freedom. Appropriate static spring constants can be evaluated for the elastic half space by the method of continuum mechanics.

   Fig 1.Plan and Elevation of shear wall Building

   Fig 2 Elevation of Bay Building

3. METHOD OF ANALYSIS

   The model is prepared in Etaab 2013 and non-linear static analysis id performed for the models.six models are prepared and the analysis is performed. various result values are listed in tables below.

   Table 1 Seismic analysis parameters for shear wall without opening by using ESA

   Table 2 Seismic analysis parameters for shear wall with 10% opening by using ESA

   Table 3 Seismic analysis parameters for shear wall with 20% opening by using ESA

   Table 4 Seismic analysis parameters for shear wall with 30% opening by using ESA

   Table 5 Seismic analysis parameters for shear wall with 40% opening by using ESA

4. INPUT DESIGN DATA FOR BUILDING Material Properties :

   Concrete

   i. Ec = 25 106 KN/m2

   ii. c = 25 KN/m3 Brick masonry

   i. Em = 13.8 106 KN/m2

   ii. m = 20 KN/m3 Assumed Dead load intensities :

   1. Floor finishes = 1.0 KN/m2

   2. Roof finishes = 2.0 KN/m2 Member properties :

   1. Thickness of Slab = 0.200 m

   2. Column size = (0.230 m 0.500 m)

   3. Beam size = (0.30 m 0.400 m)

   4. Thickness of wall = 0.250 m Earthquake load : As per IS-1893 (Part 1) 2002

   Type of soil : Type II, Medium as per IS: 1893 Seismic Zone = Zone III

   Type of Building = Public

5. RESULTS OF PARAMETRIC STUDY

1. Natural Time Period

   Figure 3 Variation of Time period and Frequency

2. Story Stiffness

   Figure 4 Variation of story stiffness for bare, with shear wall and with openings of 10%, 20%, 30% and 40%

3. Centre of Mass Displacement

   Figure 5 Variation of centre of mass displacement in X direction for bare, with shear wall and with openings of 10%, 20%, 30% and 40%

   Figure 6 Variation of centre of mass displacement in Y direction for bare, with shear wall and with openings of 10%, 20%, 30% and 40%

4. Story Drift

   Figure 7 Variation of story drift X direction for bare, with shear wall and with openings of 10%, 20% and 40%

   Figure 8 Variation of story drift Y direction for bare, with shear wall and with openings of 10%, 20% and 40%

5. Location of Performance Points

   Figure 9 Variation of performance point in X for bare, with shear wall and with openings of 10%, 20%, 30% and 40%

   Figure 10 Variation of performance point in X for bare, with shear wall and with openings of 10%, 20%, 30% and 40%

6. Maximum Axial Loads

   Figure 11 Maximum Axial Load Variations for Different Building Models

7. Maximum Bending Moment

   Figure 12 Variation of moments in column for Shear wall without opening and with 10%, 20%, 30% and 40% openings.

   CONCLUSION

   1. The study shows that It is found that the base shear for 10%, 20%, 30% and 40% is less than base shear for shear wall without opening..

   2. Frequency for 10%, 20% 30% and 40% is less than shear wall without opening. Frequency decreases with increase in opening.

   3. The time period for 10%, 20%, 30% and 40% openings is greater than shear wall without opening. Time period increases with increase in opening.

   4. If we compare the storey drift of building with 10%, 20%, 30% and 40% opening in shear wall and without opening in shear wall, storey drift of 10%, 20%, 30% and 40% opening is greater than without opening.

      REFERENCES

      1. Vojko Kilar and Peter Fajfar, simple push-over analysis of asymmetric buildings University of Ljubljana, Faculty of Civil and Geodetic Engineering Institute of Structural and Earthquake Engineering.

      2. Alessandro Zona, Graziano Leoni, Andrea DallAsta, Angela Scorpecci Seismic behaviour and design of innovative hybrid coupledshear wallsEtabs Integrated Building Design Software,

         Computers and structures, Inc. Berkeley, California,USA

      3. G. C. Bajoria and Abhijit K. Agrawal, Behaviour of coupled shear wall and shear core in lateral loading, Journal of Structural Engineering Vol. 25, No. 3, October 1998

      4. K. K. Koo and Y. K.Cheung, The static analysis of multi-bay coupled shear walls, Building and Enviornment,Vol.19, No-2, pp 93-99,1984.

      5. M. Qamaruddin and A.L.M. Mauroof, A new model for lateral stiffeness of shear wallswith openings, Journal of Structural Engineering, Vol.25 No 2, July 1998, pp 103-107.

      6. Murty. C. V. R, Why are Buildings with Shear walls Preferred in seismic regions?, Earthquake Tip-23, IIT-Kanpur.

      7. O. Aksogan,M. Bikce, E. Emsen, H.M. Arslan, A simplified dynamic analysis of multi-bay stiffened coupled shear walls, Advances in Engineering Software 38 (2007) pp 552-560.

      8. Koushik Bhattacharya, Sekhar Chandra Dutta. Assessing lateral period of building frames incorporating soil-flexibility Journal of sound and vibration 269 (2004), pp 795-821.

      9. S. K. Madan, Design forces for coupling beams of shear walls subjected to seismic forces, The Indian Concrete Journal,

         November 2006.pp 46-50

      10. Pankaj Agarwal and Manish Shrikhande Earthquake resistant design of structure