International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 04 Issue: 07 | July -2017
p-ISSN: 2395-0072
www.irjet.net
Elastic and Inelastic Responses of Multi-Storey Buildings Symmetric and Asymmetric in Plan Chandana S1, B K Raghu Prasad2, Amarnath K3 1PG
Student, Department of Civil Engineering, The Oxford College of Engineering, Bengaluru, Karnataka, India Department of Civil Engineering, The Oxford College of Engineering, Bengaluru, Karnataka, India 3Professor and Head of the Department, Department of Civil Engineering, The Oxford College of Engineering, Bengaluru, Karnataka, India ---------------------------------------------------------------------***--------------------------------------------------------------------2Professor,
Abstract - The behaviour of high rise building during strong earthquake shaking depends on the distribution of stiffness, strength and mass between the storeys of a building. Regular and irregular buildings are classified based on the distribution of the above parameters either over the height or length or width of a building.
In this paper, the performance and behaviour of both regular and irregular G+20 reinforced concrete buildings under seismic loading are considered for the study. Two types of irregularities which are in stiffness and mass are considered. Shear walls are provided at different locations. Ductility based design using IS 13920 is carried out. Modeling of building is done using STAAD-Pro V8i and seismic analysis is carried out using response spectrum analysis method. Different parameters like time period, storey displacements, storey drifts and base shear are obtained. By using these parameters a comparative study has been made between regular and irregular buildings. Key Words: Ductility, mass irregularity, stiffness irregularity, shear wall, response spectrum method
1. INTRODUCTION Earthquake is the wave like motion generated by forces as a result of release of energy in the Earth’s crust. This release of energy can be caused by sudden dislocations of segments of crust volcanic eruptions. Earthquake shaking may cause loss of life and destruction of properties. As per IS 1893, the irregularity in the building structures may be due to irregular distributions in their mass, strength and stiffness along the height or length or width of building. There are two types of irregularities1. Irregularities in plan 2. Irregularities over height
2. METHODOLOGY In this study regular and irregular of reinforced concrete buildings are considered for the analysis namely, structure symmetric in plan with shear walls at different locations and in different directions, structure unsymmetric in plan and structure with mass distribution irregular over height. The © 2017, IRJET
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Impact Factor value: 5.181
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structural details of a regular building are shown in tables below.
2.1 Structural details Table1: Structural details Grade of concrete, fck M30 Grade of steel, fst Fe415 Young’s modulus of M30 27386.12 N/mm2 concrete, E Young’s modulus of brick 3.85x106 kN/m2 masonry Concrete density 25 kN/m3 Density of infill 20 kN/m3
2.2 Model description Table 2: Model description Number of bays in x-direction
5
Number of bays in z-direction
3
Width of single bay in both the directions Number of storeys Height of each storey Depth of foundation Column dimensions Beam dimensions Infill wall Slab Shear wall
5.0m G+20 3.0m 1.5m 600 mm x 1000 mm 300 mm x 600 mm 300 mm thick 150 mm thick 500mm thick
2.3 Earthquake load details Table 3: Earthquake load details Earthquake Zone V Zone factor 0.36 Damping ratio Importance factor Type of soil Type of structure Response reduction factor
ISO 9001:2008 Certified Journal
5% 1 Hard Special moment resisting frame 5
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