DYNAMIC ANALYSIS OF HIGH RISE STRUCTURES UNDER DIFFERENT TYPE OF REINFORCED CONCRETE SHEAR WALL FOR AN EARTHQUAKE RESISTANT BUILDING

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Shear walls are a type of structural system that provides lateral resistance to a building or structure. They resist in-plane loads that are applied along its height. The applied load is generally transferred to the wall by a diaphragm or collector
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    International Journal of Innovative Research in Advanced Engineering (IJIRAE)   ISSN: 2349-2163 Issue 01, Volume 5 ( January 2018 )   www.ijirae.com    ___________________________________________________________________________________________________ IJIRAE: Impact Factor Value – SJIF: Innospace, Morocco (2016): 3.916 | PIF: 2.469 | Jour Info: 4.085 | ISRAJIF (2016): 3.715 | Indexcopernicus: (ICV 2016): 64.35  IJIRAE © 2014- 18, All Rights Reserved Page –26 DYNAMIC ANALYSIS OF HIGH RISE STRUCTURES UNDER DIFFERENT TYPE OF REINFORCED CONCRETE SHEAR WALL FOR AN EARTHQUAKE RESISTANT BUILDING Mahdi Hosseini   Ph.D. scholar student in Structural Engineering, Dept. of   Civil Engineering, Jawaharlal Nehru Technological University Hyderabad (JNTUH), Hyderabad, Telangana , India   civil.mahdi.hosseini@gmail.com   Prof.N.V.Ramana Rao   Professor, Dept. of   Civil Engineering, Jawaharlal Nehru Technological University Hyderabad (JNTUH), Hyderabad, & Director of National Institute of Technology Warangal ,Telangana, India Manuscript History Number: IJIRAE/RS/Vol.05/Issue01/JAAE10085 DOI:   10.26562/IJIRAE.2018.JAAE10085   Received: 09, December 2017 Final Correction: 28, December 2017 Final Accepted: 22, January 2018 Published: January 2018 Citation:   Hosseini & Ramana (2018). DYNAMIC ANALYSIS OF HIGH RISE STRUCTURES UNDER DIFFERENT TYPE OF REINFORCED CONCRETE SHEAR WALL FOR AN EARTHQUAKE RESISTANT BUILDING. IJIRAE::International Journal of Innovative Research in Advanced Engineering, Volume V, 26-73. doi: 10.26562/IJIRAE.2018.JAAE10085   Editor: Dr.A.Arul L.S, Chief Editor, IJIRAE, AM Publications, India Copyright: ©2018 This is an open access article distributed under the terms of the Creative Commons Attribution License, Which Permits unrestricted use, distribution, and reproduction in any medium, provided the srcinal author and source are credited  Abstract--  Shear walls are a type of structural system that provides lateral resistance to a building or structure. They resist in-plane loads that are applied along its height. The applied load is generally transferred to the wall by a diaphragm or collector or drag member. In the present work thirty story building with C Shape, Box shape, E Shape, I shape and Plus shape RC Shear wall at the center in Concrete Frame Structure with fixed support conditions under different type of soil for earthquake zone V as per IS 1893 (part 1) : 2002 in India are analyzed using software ETABS by Dynamic analysis. All the analyses has been carried out as per the Indian Standard code books. This paper aims to Study the behaviour of high rise structure with dual system with Different Type of RC Shear Walls (C,Box,E,I and Plus shapes) under different type of soil condition with seismic loading. Estimation of structural response such as; storey displacements, storey stiffness, Lateral loads, Mode shape of shear wall, Time period and frequency is carried out. In dynamic analysis; Response Spectrum method is used. Keywords-- Dynamic Analysis; Soft; Medium &Hard Soil; Structural Response; RC Shear Walls; storey displacements; storey stiffness; Lateral loads; Mode shape of shear wall ; Time period and frequency; I.   INTRODUCTION Shear Wall is a Structural Element used to Resist Lateral/Horizontal/Shear Forces Parallel to the Plane of the Wall By: Cantilever Action For Slender Walls Where The Bending Deformation is Dominant.   Truss Action For Squat/Short Walls Where The Shear Deformation Is Dominant.   Shear walls resist two types of forces: shear forces and uplift forces. Connections to the Structure above transfer horizontal forces to the shear wall. This transfer creates shear forces throughout the height of the wall between the top and bottom shear wall connections.    International Journal of Innovative Research in Advanced Engineering (IJIRAE)   ISSN: 2349-2163 Issue 01, Volume 5 ( January 2018 )   www.ijirae.com    ___________________________________________________________________________________________________ IJIRAE: Impact Factor Value – SJIF: Innospace, Morocco (2016): 3.916 | PIF: 2.469 | Jour Info: 4.085 | ISRAJIF (2016): 3.715 | Indexcopernicus: (ICV 2016): 64.35  IJIRAE © 2014- 18, All Rights Reserved Page –27 The strength of the lumber, sheathing and fasteners must resist these shear forces or the wall will tear or “shear” apart uplift forces exist on shear walls because the horizontal forces are applied to the top of the wall. These uplift forces try to lift up one end of the wall and push the other end down. In some cases, the uplift force is large enough to tip the wall over. Uplift forces are greater on tall short walls and less on low long walls. Bearing walls have less uplift than non-bearing walls because gravity loads on shear walls help them resist uplift. Shear walls need hold own devices at each End when the gravity loads cannot resist all of the uplift. The holds own device then provides the necessary uplift resistance.   Site selection   The seismic motion that reaches a structure on the surface of the earth is influenced by local soil conditions. The subsurface soil layers underlying the building foundation may amplify the response of the building to earthquake motions srcinating in the bedrock. For soft soils the earthquake vibrations can be significantly amplified and hence the shaking of structures sited on soft soils can be much greater than for structures sited on hard soils. Hence the appropriate soil investigation should be carried out to establish the allowable bearing capacity and nature of soil. The choice of a site for a building from the failure prevention point of view is mainly concerned with the stability of the ground. The very loose sands or sensitive clays are liable to be destroyed by the earthquake, so much as to lose their srcinal structure and thereby undergo compaction. This would result in large unequal settlements and damage the building. If the loose cohesion less soils are saturated with water they are likely to lose their shear resistance altogether during ground shaking. This leads to liquefaction. Although such soils can be compacted, for small buildings the operation may be too costly and the sites having these soils are better avoided. For large building complexes, such as housing developments, new colonies, etc. this factor should be thoroughly investigated and the site has to be selected appropriately. Therefore a site with sufficient bearing capacity and free from the above defects should be chosen and its drainage condition improved so that no water accumulates and saturates the ground especially close to the footing level.   Bearing capacity of foundation soil   Three soil types are considered here: I.   Hard - Those soils, which have an allowable bearing capacity of more than 10t/m2.  II.   Medium  - Those soils, which have an allowable bearing capacity less than or equal to 10t/m2  III.   Soft - Those soils, which are liable to large differential settlement or liquefaction during an earthquake.  II. METHODOLOGY    Dynamic analysis   Dynamic analysis shall be performed to obtain the design seismic force, and its distribution in different levels along the height of the building, and in the various lateral load resisting element, for the following buildings:   Regular buildings: Those greater than 40m in height in zones IV and V, those greater than   90m in height in zone II and III.   Irregular buildings: All framed buildings higher than 12m in zones IV and V, and those   greater than 40m in height in zones II and III. The analysis of model for dynamic analysis of buildings with unusual configuration should be such that it adequately models the types of irregularities present in the building configuration. Buildings with plan irregularities, as defined in Table 4 of IS code: 1893-2002 cannot be modelled for dynamic analysis.   Dynamic analysis may be performed either by the TIME HISTORY METHOD or by the RESPONSE SPECTRUM METHOD Response Spectrum Method   The word spectrum in engineering conveys the idea that the response of buildings having a broad range of periods is summarized in a single graph. This method shall be performed using the design spectrum specified in code or by a site-specific design spectrum for a structure prepared at a project site. The values of damping for building may be taken as 2 and 5 percent of the critical, for the purposes of dynamic of steel and reinforce concrete buildings, respectively. For most buildings, inelastic response can be expected to occur during a major earthquake, implying that an inelastic analysis is more proper for design. However, in spite of the availability of nonlinear inelastic programs, they are not used in typical design practice because:   1- Their proper use requires knowledge of their inner workings and theories. design criteria, and   2- Result produced are difficult to interpret and apply to traditional design criteria, and   3- The necessary computations are expensive.   Therefore, analysis in practice typically use linear elastic procedures based on the response spectrum method. The response spectrum analysis is the preferred method because it is easier to use.   Response Spectrum Analysis   This method is also known as modal method or mode superposition method. It is based on the idea that the response of a building is the superposition of the responses of individual modes of vibration, each mode responding with its own particular deformed shape, its own frequency, and with its own modal damping.    International Journal of Innovative Research in Advanced Engineering (IJIRAE)   ISSN: 2349-2163 Issue 01, Volume 5 ( January 2018 )   www.ijirae.com    ___________________________________________________________________________________________________ IJIRAE: Impact Factor Value – SJIF: Innospace, Morocco (2016): 3.916 | PIF: 2.469 | Jour Info: 4.085 | ISRAJIF (2016): 3.715 | Indexcopernicus: (ICV 2016): 64.35  IJIRAE © 2014- 18, All Rights Reserved Page –28 According to IS-1893(Part-l):2002, high rise and irregular buildings must be analyzed by response spectrum method using design spectra shown in Figure 4.1. There are significant computational advantages using response spectra method of seismic analysis for prediction of displacements and member forces in structural systems. The method involves only the calculation of the maximum values of the displacements and member forces in each mode using smooth spectra that are the average of several earthquake motions. Sufficient modes to capture such that at least 90% of the participating mass of the building (in each of two orthogonal principle horizontal directions) have to be considered for the analysis. The analysis is performed to determine the base shear for each mode using given building characteristics and ground motion spectra. And then the storey forces, accelerations, and displacements are calculated for each mode, and are combined statistically using the SRSS combination. However, in this method, the design base shear (V B ) shall be compared with a base shear (V b ) calculated using a fundamental period T. If is less than response quantities are (for example member forces, displacements, storey forces, storey shears and base reactions) multiplied by V B / Response spectrum method of analysis shall be performed using design spectrum. In case design spectrum is specifically prepared for a structure at a particular project site, the same may be used for design at the discretion of the project authorities. Figure 4.1 shows the proposed 5% spectra for rocky and soils sites. III. MODELING OF BUILDING   Details of the Building   A symmetrical building of plan 38.5m X 35.5m located with location in zone V, India is considered. Four bays of length 7.5m& one bays of length 8.5m along X - direction and Four bays of length 7.5m& one bays of length 5.5m along Y - direction are provided. Shear Wall is provided at the center core of building model.   Structure 1 : In this model building with 30 storey is modeled as a (Dual frame system with shear wall (Plus Shape) at the center of building, The shear wall acts as vertical cantilever. Structure 2  : In this model building with 30 storey is modeled as (Dual frame system with shear wall (Box Shape) at the center of building ,The shear wall acts as vertical cantilever.   Structure 3 :  In this model building with 30 storey is modeled as (Dual frame system with shear wall (C- Shape ) at the center of building, The shear wall acts as vertical cantilever. Structure 4  : In this model building with 30 storey is modeled as (Dual frame system with shear wall (E- Shape ) at the center of building ,The shear wall acts as vertical cantilever.   Structure 5  : In this model building with 30 storey is modeled as (Dual frame system with shear wall (I- Shape) at the center of building, The shear wall acts as vertical cantilever.   Load Combinations   As per IS 1893 (Part 1): 2002 Clause no. 6.3.1.2, the following load cases have to be considered for analysis:   1.5 (DL + IL)   1.2 (DL + IL ± EL)   1.5 (DL ± EL)   0.9 DL ± 1.5 EL   Earthquake load must be considered for +X, -X, +Y and –Y directions.      International Journal of Innovative Research in Advanced Engineering (IJIRAE)   ISSN: 2349-2163 Issue 01, Volume 5 ( January 2018 )   www.ijirae.com    ___________________________________________________________________________________________________ IJIRAE: Impact Factor Value – SJIF: Innospace, Morocco (2016): 3.916 | PIF: 2.469 | Jour Info: 4.085 | ISRAJIF (2016): 3.715 | Indexcopernicus: (ICV 2016): 64.35  IJIRAE © 2014- 18, All Rights Reserved Page –29 Table 1 : Details of The Building   Building Parameters   Details   Type of frame   Special RC moment resisting frame fixed at the base   Building plan   38.5m X 35.5m   Number of storeys   30   Floor height    3.5 m   Depth of Slab   225 mm   Size of beam   (300 × 600) mm   Size of column (exterior)   (1250×1250) mm up to story five   Size of column (exterior)   (900×900) mm Above story five   Size of column (interior)   (1250×1250) mm up to story ten   Size of column (interior)   (900×900) mm Above story ten   Spacing between frames   7.5-8.5 m along x - direction   7.5-5.5 m along y - direction   Live load on floor   4 KN/m2   Floor finish   2.5 KN/m2   Wall load   25 KN/m   Grade of Concrete   M 50 concrete   Grade of Steel   Fe 500   Thickness of shear wall   450 mm   Seismic zone   V   Important Factor 1.5   Density of concrete   25 KN/m3   Type of soil   Soft , Medium, Hard   Soil Type I=Soft Soil   Soil Type II=Medium Soil   Soil Type III= Hard Soil   Response spectra   As per IS 1893(Part-1):2002   Damping of structure   5 percent    Figure 1. Plan of the Structure 1    International Journal of Innovative Research in Advanced Engineering (IJIRAE)   ISSN: 2349-2163 Issue 01, Volume 5 ( January 2018 )   www.ijirae.com    ___________________________________________________________________________________________________ IJIRAE: Impact Factor Value – SJIF: Innospace, Morocco (2016): 3.916 | PIF: 2.469 | Jour Info: 4.085 | ISRAJIF (2016): 3.715 | Indexcopernicus: (ICV 2016): 64.35  IJIRAE © 2014- 18, All Rights Reserved Page –30 Figure 2. 3D view showing shear wall location   for Structure 1   Figure3. Plan of the Structure 2   Figure 4. 3D view showing shear wall location for Structure2
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