Evaluation of Multi-Storey Building by Changing the Location of Shear Walls

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Evaluation of Multi-Storey Building by Changing the Location of Shear Walls

Prathibha Reddy T

Civil Engineering Department,

Brindavan Groups of Institutions, Bangalore 560064, India

Abstract:- In this study the 15 storey building is considered with each storey height of 3m. These buildings are analysied and designed as per Indian Code of Practice for Seismic Resistant Design and for wind load calculation. For the buildings base supports are assumed to be fixed. The sections of structural elements like beams and columns are considered as square and rectangular shapes. Constant storey height is maintained for all storeys of the buildings are assumed to be constant including the ground storey. The buildings are modeled and analyzed using software ETAB Nonlinear V9.7.0.Seven different models are studied with and without shear wall at different position in the building.

In the present study an attempt has been made to check the performance of high rise building with shear wall at the different position with seismic zone IV. Both Elastic static analysis and dynamic analysis (ESA) are carried out to compare the results

Keywords: Shear walls, Evaltion, Locations, Muti-storey

  1. INTRODUCTION

    A vertical plate like RC wall in reinforced concrete building, referred to as SHEAR WALL. Walls of the building are continuous throughout the height and usually start at foundation level. Shear walls acts a vertical oriented wide beams that carry earthquake loads downward to the foundation. Shear walls are provided along both length & width of building. Most RC building has columns with shear walls. These columns & shear walls carry lateral loads & gravity load respectively. Shear walls offer high

    strength & stiffness to building in the direction of their orientation, that

    considerably reduces damage to structure and its contents and thereby reduces lateral sway of the building. Shear wall buildings are typically regular in elevation and in plan. As a part of an earthquake resistant building design, under the earthquake load the lateral displacement is decreased by inserting the walls in building plans and shear wall structure can be obtained.

  2. RC SHEAR WALL IN BUILDING

    Shear walls should give the required lateral strength to resist horizontal earthquake forces. Shear walls are strong enough to transfer the horizontal forces to the other element in the load path under them. These other elements in the load path may be slabs, floors, foundation walls or footings.

    Shear walls additionally give lateral stiffness to protect the floor or roof above from excessive side-sway. Shear walls are stiff enough to prevent the roof and floor framing members from sliding off their supports. Sufficiently stiff buildings typically suffer less non-structural harms.

    RC shear walls gives great strength and stiffness to buildings within the direction of their orientation, that considerably

    reduces lateral sway of the building and therefore it decrease the structure damages. Due to the large horizontal force of earthquake on shear wall, the effect of overturning on shear wall will also be large. Therefore shear walls in buildings should be located symmetrically in plan to reduce ill-effects of twist in buildings. They can be placed symmetrically along both the directions of plan.

    Fig 1. RC Shear Wall in Building

  3. SEISMIC BEHAVIOUR OF SHEAR WALL

    According to position of shear wall, the nature of stresses generation in the shear wall is different. Placing the shear wall at very near to the Centre of stiffness behave as a Vertical bending element and also the shear wall placing at corner of the building are can be in axial tension or in axial compression followed by the Lateral Force direction.

    The drift generated is more compare to shear walls placed at the corner of the building. Thats why it is important and necessary to consider the correct or optimum location of the shear walls in the structure that may helps to reduce the stresses in all the structural members of the structure.

  4. METHODOLOGY

    In this study the 15 storey building is considered with each storey height of 3m. These buildings are analysied and designed as per Indian Code of Practice for Seismic Resistant Design and for wind load calculation. For the buildings base supports are assumed to be fixed. The sections of structural elements like beams and columns are considered as square and rectangular shapes. Constant storey height is maintained for all storeys of the buildings are assumed to be constant including the ground storey. The buildings are modeled and analyzed

    using software ETAB Nonlinear V9.7.0.four different models are studied with and without shear wall at different position in the building.

      1. Model Details

        Consider RC frame shear wall building of 15 stories with and without shear wall at different position for regular and irregular structure. Total of 4 models are considered for analysis: Model 1: Regular building without shear wall Model 2: Regular building with shear wall at position 1 (corners)

        Model 3: Regular building with shear wall at position 2 Model 4: Regular building with shear wall at position 3 (centre)

      2. Material Properties

        -Modulus of elascity ,

        -Modulus of elascity for M30 27386 N/mm2

        • Modulus of elascity for M25 – 25000 N/mm2

        • Weight/unit volume of concrete – 25 kN/m3

        • Mass/unit volume of concrete – 2.55 kN/m3

        • Grade of steel Fe 415

        Table.1 Grade of Concert

      3. Sizes of the Members

        The details and the sizes of the members will be clarified clearly in the table below:

        S.No

        Specifications

        Size

        1

        Dimensions for Plan

        30 m x 30 m (X*Y)

        2

        Length along X- direction

        30 m (6 Bays)

        3

        Length along Z- direction

        30 m (6 Bays)

        4

        storey height

        3.0 m

        5

        Plinth Level

        1.7 m

        6

        Building height (G+15)

        46.7 m

        7

        Thickness of Slab

        150 mm

        8

        Beam dimensions

        0.35 m x 0.45 m

        9

        Column dimension

        0.35 m x 0.60 m

        10

        Shear wall size

        150 mm

        Table.2 Specification of members

      4. Figures of models

        Fig.1.Model 1: Regular Building without Shear Wall

        Fig.2.Model 2: Regular Building with Shear Wall at Position 1 (corners)

        Fig.3.Model 3: Regular Building with Shear Wall at Position 2

        Fig.4.Model 4: Regular Building with Shear Wall at Position 3 (center)

  5. RESULTS AND DISCUSSION

    To study the response of lateral load effect on structure we used RC frame 15 storied regular and irregular building with shear wall at different location for seismic zone IV and wind load.

    16

    15

    14

    13

    12

    11

    10

    9

    8

    7

    6

    5

    4

    3

    2

    1

    0

    16

    15

    14

    13

    12

    11

    10

    9

    8

    7

    6

    5

    4

    3

    2

    1

    0

    model

    1(without

    sw) model

    (corner)

    model

    1(without

    sw) model

    2(corner)

    model

    3(corner 2)

    0

    model

    3(corner 2)

    0

    20

    20

    40

    Displacements

    40

    Displacements

    60

    60

    80

    80

    Storeys

    Storeys

    Lateral Storey Displacement for Building in X-Direction for Elastic Static Analysis (ESA):

    Above fig shows displacement v/s no. of storeys for regular and irregular model having shear wall at different location along X-direction for seismic zone IV and wind load, analyse is carried out for Elastic Static Analysis (ESA).From graph plotted indicates that:

        1. The maximum displacement along X-direction for regular structure without shear wall is 66.29mm

        2. The maximum displacement along X-direction for regular structure with shear wall at position 1 (corner) is 54.92mm

        3. The maximum displacement along X-direction for regular structure with shear wall at position 2 is 52.60mm

        4. The maximum displacement along X-direction for regular structure with shear wall at position at position 3 (centre) is 36.17mm

          STOREY DISPLACEMENT (mm) RSA

          STOR EYS

          model 1

          model 2

          model 3

          model 4

          TERR ACE

          47.5969

          36.4151

          34.9802

          23.8291

          STOR Y14

          46.76

          34.0971

          32.831

          22.1649

          STOR Y13

          45.5097

          31.6835

          30.5822

          20.4273

          STOR Y12

          43.833

          29.1922

          28.2465

          18.6476

          STOR Y11

          41.759

          26.6211

          25.8207

          16.835

          STOR Y10

          39.3161

          23.9787

          23.3125

          15.005

          STOR Y9

          36.529

          21.2771

          20.7334

          13.1743

          STOR Y8

          33.4205

          18.5325

          18.0995

          11.361

          STOR Y7

          30.0118

          15.766

          15.4321

          9.5843

          STOR Y6

          26.3226

          13.0074

          12.7607

          7.8653

          STOR Y5

          22.3703

          10.2981

          10.1268

          6.2269

          STOR Y4

          18.1669

          7.6956

          7.5871

          4.6942

          STOR Y3

          13.7242

          5.277

          5.2178

          3.2958

          STOR Y2

          9.098

          3.143

          3.119

          2.065

          STOR Y1

          4.5202

          1.4223

          1.4183

          1.0381

          GF

          0.8109

          0.4124

          0.4708

          0.4174

          STOREY DISPLACEMENT (mm) RSA

          STOR EYS

          model 1

          model 2

          model 3

          model 4

          TERR ACE

          47.5969

          36.4151

          34.9802

          23.8291

          STOR Y14

          46.76

          34.0971

          32.831

          22.1649

          STOR Y13

          45.5097

          31.6835

          30.5822

          20.4273

          STOR Y12

          43.833

          29.1922

          28.2465

          18.6476

          STOR Y11

          41.759

          26.6211

          25.8207

          16.835

          STOR Y10

          39.3161

          23.9787

          23.3125

          15.005

          STOR Y9

          36.529

          21.2771

          20.7334

          13.1743

          STOR Y8

          33.4205

          18.5325

          18.0995

          11.361

          STOR Y7

          30.0118

          15.766

          15.4321

          9.5843

          STOR Y6

          26.3226

          13.0074

          12.7607

          7.8653

          STOR Y5

          22.3703

          10.2981

          10.1268

          6.2269

          STOR Y4

          18.1669

          7.6956

          7.5871

          4.6942

          STOR Y3

          13.7242

          5.277

          5.2178

          3.2958

          STOR Y2

          9.098

          3.143

          3.119

          2.065

          STOR Y1

          4.5202

          1.4223

          1.4183

          1.0381

          GF

          0.8109

          0.4124

          0.4708

          0.4174

          Lateral Storey Displacement for Building in X-direction for Response Spectrum Analysis (RSA)

          STOREY DISPLACEMENT (mm) ESA

          STOREYS

          model 1

          model 2

          model 3

          model 4

          TERRACE

          66.2879

          54.9242

          52.6011

          36.1676

          STORY14

          64.8978

          51.4099

          49.3385

          33.6024

          STORY13

          62.7989

          47.7079

          45.8852

          30.9126

          STORY12

          59.9823

          43.8372

          42.2536

          28.1465

          STORY11

          56.5244

          39.794

          38.4393

          25.3202

          STORY10

          52.5177

          35.6012

          34.4637

          22.4606

          STORY9

          48.0538

          31.2975

          30.3642

          19.5986

          STORY8

          43.2183

          26.9363

          26.1925

          16.7691

          STORY7

          38.0892

          22.5834

          22.0122

          14.0099

          STORY6

          32.7371

          18.3157

          17.8983

          11.3614

          STORY5

          27.2253

          14.2213

          13.9365

          8.8662

          STORY4

          21.6121

          10.3995

          10.2239

          6.5688

          STORY3

          15.9594

          6.9619

          6.8702

          4.5153

          STORY2

          10.363

          4.0351

          4.001

          2.755

          STORY1

          5.0666

          1.7651

          1.7621

          1.3374

          GF

          0.8984

          0.474

          0.538

          0.501

          Storey Displacements Along X-Axis(ESA)

          Storey Displacements Along X-Axis(ESA)

          Storey Displacements Along X-Axis(RSA)

          Storey Displacements Along X-Axis(RSA)

          16

          15

          14

          13

          12

          11

          10

          9

          8

          7

          6

          5

          4

          3

          2

          1

          0

          6

          15

          14

          13

          12

          11

          10

          9

          8

          7

          6

          5

          4

          3

          2

          1

          0

          model

          3(corner 2)

          0

          model

          3(corner 2)

          0

          Displacements(mm)

          Displacements(mm)

          20 40 60

          20 40 60

          Storeys

          Storeys

          Above Fig shows displacement v/s no. of storeys for regular and irregular model having shear wall at different location along X-direction for seismic zone IV and wind load, analyse is carried out for Response Spectrum Analysis (RSA).From graph plotted indicates that:

          1. The maximum displacement along X-direction for regular structure without shear wall is 47.60mm

          2. The maximum displacement along X-direction for regular structure with shear wall at position 1 (corner) is 36.42mm

          3. The maximum displacement along X-direction for regular structure with shear wall at position 2 is 34.98mm

          4. The maximum displacement along X-direction for regular structure with shear wall at position at position 3 (centre) is 23.83mm

    REFERENCES

    model

    1(without sw)

    model 2(corner)

    model

    1(without sw)

    model 2(corner)

    1. BurucBurak and HakkiGurhanComlekoglu (2013) ,Effect of Shear Wall Area to Floor Area Ratio on the Seismic Behavior of Reinforced Concrete Buildings., Journal of Structural Engineering © ASCE,Volume139, ISSN: 0733-9445.

    2. Ahmet Tuken and Nadeem A. Siddiqui (2012) ,Assessment of ShearWall Quantity in Seismic-Resistant Design of Reinforced Concrete Buildings Department of Civil Engineering, King Saud University,springer

    3. IlkerFatih Kara and Cengiz Dundar (2009) ,Prediction of deflection of reinforced concrete shear walls ,ELESVIER.

    4. Hyun-Su Kima , Dong-Guen Lee and Chee KyeongKimb (2005)

      ,Efficient Three-Dimensional Seismic Analysis of a High-Rise Building Structure with Shear walls,Engineering Structure, ELESVIER.

    5. Adrián Beko, Peter Rosko, Helmut Wenzel, Pierre Pegon, Damijan Markovic and Francisco Javier Molina(30 July 2015), RC shear walls: Full-scale cyclic test, insights and derived analytical model, Engineering Structure, ELESVIER.

    6. Jinhan Kwon and Wassim M. Ghannoum (2016) , Assessment of international standard provisions on stiffness of reinforced concrete moment frame and shear wall buildings Engineering Structure, ELESVIER.

    7. Farid Chalah, Lila Chalah-Rezguia ,KamelFaleka , Salah Eddine Djellaba and Abderrahim Bali(2014) , Fundamental Vibration Period of SW Buildings,Science Direct, ELESVIER.

    8. P.V. Sumanth Chowdary and Senthil Pandian. M (2014) , A Comparative Study on RCC Structure with and without Shear wall, International Journal for Scientific Research & Development (IJSRD) , Vol. 2, ISSN : 2321-0613.

    9. Prof. Jayasree Ramanujan, Mrs. Bindu Sunil , Dr. LajuKottalliland Prof. Mercy Joseph Poweth (2014) , Effect of Shear Wall Location in Buildings Subjected to Seismic Loads, ISOI Journal of Engineering and Computer science,Volume 1 Issue 1; Page No. 07-17.

    10. N. Janardhana Reddy, D. GosePeera and T. Anil Kumar Reddy(2015)

      ,Seismic Analysis of Multi-Storied Building with Shear Walls Using ETABS-2013 International Journal of Science and Research (IJSR), Volume 4, ISSN: 2319-7064.

  6. CONCLUSIONS

    1. Shearwall affects the stiffness of the

      structure , walls increase the strength to the structure to resists the lateral forces by increasing the performance of the structure.

    2. Storey displacement, has been reduced for all structures with shear walls in the middle as compared to corner for regular structure.

    3. The maximum lateral storey displacement exists at the terrace level for all types of structures.

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