EATHQUAKE RESISTANCE DESIGN OF OPEN GROUND STOREY BUILDING

EATHQUAKE RESISTANCE DESIGN OF

OPEN GROUND STOREY BUILDING

SIRIPURAPU PRUDHVIRAJ1, Dr. VEEREDHI LAKSHMI SHIREEN BANU2

1 Student, Malla Reddy Engineering College (Autonomous), Maisammaguda, Medchal(M), Malkajgiri(D),

500100 2Professor, Malla Reddy Engineering College (Autonomous), Maisammaguda, Medchal(M),

Malkajgiri(D), 500100

Abstract— Now a day’s reinforced concrete (RC) wall-frame buildings are widely recommended for urban construction in areas with

high seismic hazard. Presence of shear walls imparts a large stiffness to the lateral force resisting system of the RC building. Proper

detailing of shear walls can also lead to ductile behavior of such structures during strong earthquake shaking. One of the major parameters

influencing the seismic behavior of shear wall frame buildings is the shear wall area ratio. Thus shear wall area ratio is set as a key

parameter which is needed to be study.

An analytical study is performed to evaluate the effect of Shear Wall Area to floor area ratio (SWA/FA %) on the seismic behavior of

multistoried RC structures with open storey at ground floor. For this purpose, 2 building models that have 9 and 13 stories are generated.

For G+9 SWA/FA % is decreased from 0.48% to 0.31% and analysed. For G+13 SWA/FA % is increased from 0.32% to 0.4% and

analysed. Then, the behavior of these building models under earthquake loading is examined by carrying out response spectrum analysis

using structural analysis software E-TABS. Response spectrum analysis is done according to seismic code IS 1893:2002. The main

parameters considered in this study are the relation SWA / FA % has with storey displacement, storey drift, storey shear and storey

stiffness. The analytical results indicated that building models with more SWA / FA % behaved adequately under earthquake loads.

Keywords— Response spectrum analysis, storey displacement, storey drift, storey shear, storey stiffness, Etabs

I. INTRODUCTION

In the last few decades, shear walls have been used extensively in countries especially where high seismic risk is observed. The

major factors for inclusion of shear walls are ability to minimize lateral drifts, inter storey displacement and excellent performance

in past earthquake record. Shear walls are designed not only to resist gravity loads but also can take care overturning moments as

well as shear forces. They have very large in plane stiffness that limit the amount of lateral displacement of the building under lateral

loadings. Shear walls are intended to behave elastically during moderate or low seismic loading to prevent non-structural damage

in the building. However, it is expected that the walls will be exposed to inelastic deformation during less or frequent earthquakes.

Thus, shear walls must be designed to withstand forces that cause inelastic deformations while maintaining their ability to carry

load and dissipate energy. Structural and non-structural damage is expected during severe earthquakes however; collapse prevention

and life safety is the main concern in the design.

The shear wall area to floor area ratio (also referred to as shear wall ratio), the wall aspect ratio, and the wall configuration in plan

are indicated as important parameters that affect the detailing of a shear wall for RC design. However, among these parameters,

shear wall ratio is also accepted as an essential parameter affecting the global performance of a building under severe ground motions.

Therefore, shear wall ratio is set as a key parameter to be investigated in this analytical study. The effect of shear wall ratio on

structural vulnerability could be evaluated by the variation of different parameters such as roof or inter storey drift with increasing

shear wall ratio. Lateral forces exerted by strong ground motions induce deformations on buildings leading to structural damage.

Global deformations in a structure such as roof drift and inter storey drifts are good indicators of expected damage of a building

under earthquake loading. Even so, the relationship between drift and shear wall ratio have not been deeply investigated as of now.

Independent of shear wall ratio, current building codes recommend certain limits for roof and inter storey drifts obtained from both

linear and nonlinear analyses. Eurocode 8 (European Committee for Standardization 2003) limits the elastic design inter storey

drifts, whereas the Structural Engineers Association of California (SEAOC) (1999) and Applied Technology Council (ATC) (1996)

have limits on inelastic inter storey drifts for specified performance levels. The Turkish Earthquake Code (TEC) (2007) also restricts

the inter storey drifts in linear elastic performance analysis.

The International journal of analytical and experimental modal analysis

Volume XII, Issue VI, June/2020

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II. LITERATURE SURVEY

Riddell et al. a study was performed by to define the general features of the buildings located in Vina del Mar that experienced the

1985 Chile earthquake and to identify the related earthquake damage. Data of 178 low and midrise buildings representing a stock

of 322, of which 319 have shear walls, were used in the evaluation. Most of these buildings were designed with considerably high

shear wall ratios (varying between 3.0 and 8.0%, with an average of 6.0%), independent of the number of stories. As an outcome of

this study, it can be stated that the higher the shear wall ratio used in a building, the lower the possibility of having damage in the

structural system during a strong ground motion.

Wallace and Moehle an analytical procedure is proposed by to predict the variation of roof drift with shear wall ratio. Fig. 2.1(a)

is generated following this procedure for building models having different shear wall ratios, and the effect of shear wall ratio on the

behavior is obtained for different shear wall aspect ratios. Wallace and investigated the response of shear wall buildings by using

the same procedure. Fig. 2.1(b) shows the estimated periods of the buildings with different shear wall ratios. This study indicated

that buildings with a shear wall ratio more than 1.5% in the direction of loading that has a shear wall aspect ratio equal to or less

than 5 are expected to experience roof drifts less than 1.0% under strong ground motions.

Hassan and Sozen “Seismic Vulnerability Assessment of Low-Rise Buildings in regions with infrequent earthquakes” A

simplified method proposed which enables ranking an inventory of low-rise (up to five stories) monolithic RC buildings based on

their seismic vulnerability level from low to high by using column and wall indexes. This method requires only structural dimensions

as the input and is based on effective wall and column indexes plotted in a two-dimensional form. The wall index including RC and

masonry infill walls is the ratio of the effective wall area at the base of the building to the total floor area. The column index is the

ratio of the effective column area at the base to the total floor area. The effective areas are proposed to be taken as the area of 100%

of RC walls, 10% of non-reinforced infill walls, and 50% of columns.

Ersoy and Tekel “Seismic strengthening of RC structures with exterior shear walls” In earthquake-resistant design, when a dual

system is used, the general approach is using a shear wall area to floor area ratio of about 1.0% as a rule of thumb. Some approximate

shear wall ratios are proposed in the literature to be used in preliminary design stages of shear wall-frame buildings. These ratios

are generally based on empirical values that are obtained from building surveys performed after severe earthquakes. This study

investigates the performance of exterior RC shear walls (ESW) that are placed parallel to the building’s sides. In reality, installing

a shear wall to a structural system will surely improve the seismic capacity of the structure. The main concern is whether the design

methods for the connection of old and new elements can satisfy codes. To make it clear, an experimental program was carried out

on two-storey three dimensional RC models. The program includes a reference model and a strengthened model. Additionally,

numerical solutions are presented and compared with the results of the experiments.

European Committee for Standardization Lateral forces exerted by strong ground motions induce deformations on buildings

leading to structural damage. Global deformations in a structure such as roof drift and inter story drifts are good indicators of

expected damage of a building under earthquake loading. Even so, the relationship between drift and shear wall ratio have not been

deeply investigated as of now. Independent of shear wall ratio, current building codes recommend certain limits for roof and inter

story drifts obtained from both linear and nonlinear analyses.

Gulkan and Utkutug investigated the relationship between roof drift and shear wall ratio by taking into account the shear wall

aspect ratio, which is represented as H/D [Fig. 2.2(a)]. The study by Gulkan and Utkutug emphasized the importance of a minimum

shear wall ratio that should be used in the design of RC buildings. Maximum compressive concrete strain of the shear wall member

was also investigated as a control criterion in this study. When the strain is restricted to a level of 0.003, for large wall aspect ratios,

H/D, and axial load levels, considerably higher wall ratio is required to meet this strain criterion. In Fig. 2.2(b), a strain level of

0.003 is shown with a horizontal line, and based on these results under increasing axial load ratios (N*), approximately

1.5%shearwall ratio is required to satisfy the demand for the most unfavorable conditions.

Chai and Kunnath developed graphs for estimating minimum thickness to be provided for the shear wall based on various

parameters, namely ground motion intensity, longitudinal reinforcement ratio, floor weight, wall-floor area ratio, and number of

stories. Results were presented in terms of storey height to wall thickness with respect to various parameters. Study showed that

thicker walls are required for lower a/v ratios (peak ground acceleration to peak ground velocity ratio) indicating softening of site

conditions with decreasing a/v ratios. Minimum wall thickness arrived at was compared to that of code provisions.

Sharany Haque, khan Mahmud Amanat “Seismic Vulnerability of Columns of RC frame Buildings with Open ground Storey”.

Earthquake vulnerability of buildings with open ground floors is well known around the world. Under the present socio economic

context of developing nations like Bangladesh, construction of such buildings is unavoidable. These types of buildings should

not be treated as ordinary RC framed buildings. The calculation of earthquake forces by treating them as ordinary frames results in

an underestimation of base shear. When RC framed buildings having brick masonry infill on upper floor with open ground floor

is subjected to earthquake loading, base shear can be more than twice to that predicted by equivalent earthquake force method with

or without infill or even by response spectrum method when no infill in the analysis model. It can be suggested that the base shear

calculating by equivalent static method may at least be doubled for the safer design of the columns of open ground floor.



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III. MODELLING

In the present study lateral load analysis is performed on four building models that have two nine and thirteen stories with the same

plans but different shear wall area ratios are generated for the application of response spectrum analysis. Response Spectrum

Analysis is carried out by using seismic code IS 1893:2002. The Shear wall area ratio is determined by dividing the total shear wall

area in one principal direction to the plan area of the ground floor (∑Aw/Ap). In this analytical study, shear wall area ratio of about

0.48%, 0.31 and 0.32% and 0.40% are selected to investigate the seismic behavior of multistoried G+9 and G+13 RC buildings with

ground floor as open ground storey respectively.

A. Description of the Building Model’s

TABLE I

DESCRIPTION OF BUILDING MODELS

Model Id Number

of Storey

SWA / FA %

X -Direction Y -Direction

1 9 0.48 0.48

2 9 0.31 0.31

3 13 0.32 0.32

4 13 0.40 0.40

Fig. 1 Plan layout of nine storey building with 0.48 SWA/FA%

Fig. 2 Isometric view and front elevation of nine storey building with 0.48 SWA/FA%

Fig. 3 Plan layout of nine storey building with 0.31 SWA/FA%



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Fig. 4 Isometric view and front elevation of nine storey building with 0.31 SWA/FA%

Fig. 5 Plan layout of thirteen storey building with 0.32 SWA/FA%

Fig. 6 Isometric view and front elevation of thirteen storey building with 0.32 SWA/FA%

Fig. 7 Plan layout of thirteen storey building with 0.4 SWA/FA%



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Fig. 8 Isometric view and front elevation of thirteen storey building with 0.4 SWA/FA%

B. Design Data:

1. Material Properties:

Young’s modulus of (M20) concrete, E = 22.360 x 106 kN/m²

Density of Reinforced Concrete = 25 kN/m³

Modulus of elasticity of brick masonry = 3500 x 10³ kN/m²

Density of brick masonry = 19.2 kN/m³

Assumed Dead load intensities

Floor finishes = 1.5 kN/m²

Live load = 4 kN/ m²

2.Member properties:

Thickness of Slab = 0.125m

Column size = (0.9 m x 0.6 m)

Beam size = (0.3 m x 0.6 m)

Thickness of wall = 0.250 m

Thickness of shear wall = 0.175, 0.225, 0.275 and 0.325m

Earthquake Live Load on Slab as per clause 7.3.1 and 7.3.2 of IS 1893 (Part-I) - 2002 is calculated as:

Roof (clause 7.3.2) = 0

Floor (clause 7.3.1) = 0.5 x 4 = 2 kN/m2

IV. RESULTS AND DISCUSSION

A. Storey Displacement:

The below tables and graphs represents the relationship between storey vs. displacement for different SWA/FA% of G+9 and

G+13 buildings (0.48%, 0.31%, 0.32% and 0.40%), performed by using Response Spectrum Analysis.

TABLE 2

Storey displacements of G+9 building with 0.48 SWA/FA%

Story Elevation

m Location

For EQ X For EQ Y

X-Dir

mm

Y-Dir

mm

X-Dir

mm

Y-Dir

mm

Story9 27 Top 7.1 1.641E-02 0.1 9.2

Story8 24 Top 6.5 2.008E-02 0.1 8.5

Story7 21 Top 5.8 1.977E-02 0.1 7.6

Story6 18 Top 5.1 1.785E-02 0.1 6.8

Story5 15 Top 4.3 1.718E-02 0.1 6

Story4 12 Top 3.6 1.864E-02 4.633E-02 5.1

Story3 9 Top 3 1.759E-02 3.617E-02 4.4

Story2 6 Top 2.4 1.763E-02 4.719E-02 3.7

Story1 3 Top 1.8 0.1 0.1 3.1

Base 0 Top 0 0 0 0



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Fig. 9 Storey displacements of G+9 building with 0.48 SWA/FA% for EQ X

Fig. 10 Storey displacements of G+9 building with 0.48 SWA/FA% for EQ Y

TABLE 3


Story Elevation

m Location

For EQ X For EQ Y

X-Dir

mm

Y-Dir

mm

X-Dir

mm

Y-Dir

mm

Story9 27 Top 7.2 2.138E-02 4.621E-02 12

Story8 24 Top 6.5 1.967E-02 4.804E-02 11

Story7 21 Top 5.8 1.721E-02 4.27E-02 9.9

Story6 18 Top 5.1 1.335E-02 3.495E-02 8.7

Story5 15 Top 4.3 1.036E-02 2.91E-02 7.5

Story4 12 Top 3.6 8.092E-03 2.534E-02 6.3

Story3 9 Top 2.9 9.014E-03 2.81E-02 5.2

Story2 6 Top 2.4 8.363E-03 2.479E-02 4.2

Story1 3 Top 1.8 2.094E-02 0.1 3.2

Base 0 Top 0 0 0 0



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Fig. 11 Storey displacements of G+9 building with 0.31 SWA/FA% for EQ X


TABLE 4 Storey displacements of G+13 building with 0.32 SWA/FA%

Story Elevation

m Location

For EQ X For EQ Y

X-Dir

mm

Y-Dir

mm

X-Dir

mm

Y-Dir

mm

Story13 39 Top 27.3 1.1 1.2 25.4

Story12 36 Top 25 1 1.1 23.1

Story11 33 Top 22.6 0.9 0.9 20.8

Story10 30 Top 20.2 0.8 0.8 18.5

Story9 27 Top 17.7 0.7 0.7 16.2

Story8 24 Top 15.2 0.6 0.6 13.8

Story7 21 Top 12.7 0.5 0.5 11.5

Story6 18 Top 10.2 0.4 0.4 9.3

Story5 15 Top 7.8 0.3 0.3 7.2

Story4 12 Top 5.7 0.2 0.2 5.3

Story3 9 Top 3.7 0.2 0.2 3.7

Story2 6 Top 2.1 0.1 0.1 2.3

Story1 3 Top 0.9 0.1 0.1 1.2

Base 0 Top 0 0 0 0

Fig.13 Storey displacements of G+13 building with 0.32 SWA/FA% for EQ X



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TABLE 5


Story Elevation

m Location

For EQ X For EQ Y

X-Dir

mm

Y-Dir

mm

X-Dir

mm

Y-Dir

mm

Story13 39 Top 18.6 1 0.9 21.4

Story12 36 Top 17 1 0.8 19.5

Story11 33 Top 15.3 0.9 0.7 17.6

Story10 30 Top 13.6 0.8 0.6 15.7

Story9 27 Top 11.9 0.7 0.6 13.7

Story8 24 Top 10.2 0.6 0.5 11.8

Story7 21 Top 8.5 0.5 0.4 9.9

Story6 18 Top 6.9 0.4 0.3 8

Story5 15 Top 5.4 0.3 0.3 6.3

Story4 12 Top 4 0.2 0.2 4.7

Story3 9 Top 2.7 0.2 0.1 3.3

Story2 6 Top 1.7 0.1 0.1 2.1

Story1 3 Top 0.8 0.1 0.1 1.2

Base 0 Top 0 0 0 0

Fig.15 Storey displacements of G+13 building with 0.4 SWA/FA% for EQ X



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Fig.16 Storey displacements of G+13 building with 0.4 SWA/FA% for EQ Y

B. Storey Drift

The below tables and graphs represents the relationship between storey vs. drifts for different SWA/FA% of G+9 and G+13

buildings (0.48%, 0.31%, 0.32% and 0.40%), performed by using Response Spectrum Analysis.

TABLE 6

Storey drifts of G+9 building with 0.48 SWA/FA%

Story Elevation

m Location

For EQ X For EQ Y

X-Dir Y-Dir X-Dir Y-Dir

Story9 27 Top 0.000217 0.000003 0.000003 0.000258

Story8 24 Top 0.00023 0.000001 0.000001 0.000272

Story7 21 Top 0.000239 0.000001 0.000002 0.000281

Story6 18 Top 0.000242 0.000001 0.000002 0.000282

Story5 15 Top 0.000237 0.000001 0.000002 0.000276

Story4 12 Top 0.000224 0.000002 0.000004 0.000258

Story3 9 Top 0.000202 0.000005 0.000008 0.000229

Story2 6 Top 0.000239 0.000017 0.000022 0.000292

Story1 3 Top 0.000604 0.000019 0.000032 0.001026

Base 0 Top 0 0 0 0

Fig.17 Storey drifts of G+9 building with 0.48 SWA/FA% for EQ X



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Fig. 18 Storey drifts of G+9 building with 0.48 SWA/FA% for EQ Y

TABLE 7


Story Elevation

m Location

For EQ X For EQ Y


Story9 27 Top 0.000223 0.000001 0.000005 0.00034

Story8 24 Top 0.000238 0.000001 0.000002 0.000371

Story7 21 Top 0.000247 0.000001 0.000003 0.000392

Story6 18 Top 0.000248 0.000001 0.000002 0.000403

Story5 15 Top 0.000242 0.000001 0.000001 0.0004

Story4 12 Top 0.000226 0.000001 0.000003 0.000379

Story3 9 Top 0.000204 0.000001 0.000001 0.000337

Story2 6 Top 0.000238 0.000007 0.000016 0.000388

Story1 3 Top 0.000591 0.000007 0.000018 0.001082

Base 0 Top 0 0 0 0

Fig.19. Storey drifts of G+9 building with 0.31 SWA/FA% for EQ X

Fig.20.Storey drifts of G+9 building with 0.31 SWA/FA% for EQ Y



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TABLE 8


Story Elevation

m Location

For EQ X For EQ Y


Story13 39 Top 0.000758 0.000031 0.000034 0.000745

Story12 36 Top 0.000789 0.000032 0.000035 0.000765

Story11 33 Top 0.000813 0.000032 0.000035 0.000777

Story10 30 Top 0.000833 0.000033 0.000036 0.000783

Story9 27 Top 0.000843 0.000033 0.000035 0.00078

Story8 24 Top 0.00084 0.000032 0.000035 0.000766

Story7 21 Top 0.000822 0.000031 0.000033 0.000738

Story6 18 Top 0.000784 0.000029 0.000031 0.000695

Story5 15 Top 0.000727 0.000026 0.000029 0.000635

Story4 12 Top 0.000647 0.000023 0.000025 0.000558

Story3 9 Top 0.000543 0.000019 0.000021 0.000464

Story2 6 Top 0.000435 0.00003 0.000036 0.000402

Story1 3 Top 0.000286 0.000035 0.000038 0.000398

Base 0 Top 0 0 0 0


Fig.22 Storey drifts of G+13 building with 0.32 SWA/FA% for EQ Y



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TABLE 9


Story Elevation

m Location

For EQ X For EQ Y


Story13 39 Top 0.000535 0.000029 0.000025 0.000614

Story12 36 Top 0.000553 0.00003 0.000025 0.000633

Story11 33 Top 0.000564 0.000031 0.000026 0.000644

Story10 30 Top 0.00057 0.000031 0.000026 0.00065

Story9 27 Top 0.000569 0.000031 0.000026 0.000648

Story8 24 Top 0.000559 0.00003 0.000026 0.000636

Story7 21 Top 0.00054 0.000029 0.000025 0.000613

Story6 18 Top 0.00051 0.000028 0.000023 0.000579

Story5 15 Top 0.000468 0.000026 0.000022 0.00053

Story4 12 Top 0.000415 0.000023 0.000019 0.000469

Story3 9 Top 0.000348 0.000019 0.000016 0.00039

Story2 6 Top 0.000283 0.000015 0.000013 0.000319

Story1 3 Top 0.000273 0.000024 0.00002 0.000392

Base 0 Top 0 0 0 0


Fig.22 Storey drifts of G+13 building with 0.40 SWA/FA% for EQ Y

C. Storey Stiffness

The below tables and graphs represents the relationship between storey vs. stiffness for different SWA/FA% of G+9 and G+13




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TABLE 10

Storey stiffness values of G+9 building with 0.48 SWA/FA%

Story Elevation

m Location

For EQ X For EQ Y

X-Dir

kN/m

Y-Dir

kN/m

X-Dir

kN/m

Y-Dir

kN/m

Story9 27 Top 702957.722 0 0 590066.778

Story8 24 Top 1357824.29 0 0 1146635.869

Story7 21 Top 1823988.294 0 0 1553477.739

Story6 18 Top 2177444.545 0 0 1867202.381

Story5 15 Top 2483982.572 0 0 2142545.932

Story4 12 Top 2818864.181 0 0 2447614.198

Story3 9 Top 3292287.344 0 0 2913688.063

Story2 6 Top 3167794.437 0 0 2697384.512

Story1 3 Top 1143330.165 0 0 675340.241

Base 0 Top 0 0 0 0

Fig. 23 Storey stiffness values of G+9 building with 0.48 SWA/FA% for EQ X

Fig. 24 Storey stiffness values of G+9 building with 0.48 SWA/FA% for EQ Y



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TABLE 11


Story Elevation

m Location

For EQ X For EQ Y

X-Dir

kN/m

Y-Dir

kN/m

X-Dir

kN/m

Y-Dir

kN/m

Story9 27 Top 643944.441 0 0 425730.425

Story8 24 Top 1218499.495 0 0 782008.053

Story7 21 Top 1634653.395 0 0 1028853.36

Story6 18 Top 1957236.299 0 0 1206621.33

Story5 15 Top 2245796.468 0 0 1359987.255

Story4 12 Top 2579914.812 0 0 1539034.966

Story3 9 Top 3046214.672 0 0 1826191.055

Story2 6 Top 2950335.776 0 0 1785622.339

Story1 3 Top 1073190.774 0 0 584671.983

Base 0 Top 0 0 0 0

Fig.25 Storey stiffness values of G+9 building with 0.31 SWA/FA% for EQ X

Fig.26 Storey stiffness values of G+9 building with 0.31 SWA/FA% for EQ Y



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TABLE 12


Story Elevation

m Location

For EQ X For EQ Y

X-Dir

kN/m

Y-Dir

kN/m

X-Dir

kN/m

Y-Dir

kN/m

Story13 39 Top 172877.632 0 0 191089.607

Story12 36 Top 354492.69 0 0 397397.795

Story11 33 Top 496994.588 0 0 565998.86

Story10 30 Top 608552.094 0 0 704587.99

Story9 27 Top 699710.972 0 0 823681.929

Story8 24 Top 779981.167 0 0 933006.107

Story7 21 Top 858598.565 0 0 1042874.085

Story6 18 Top 945805.447 0 0 1165576.466

Story5 15 Top 1055455.623 0 0 1318573.449

Story4 12 Top 1211392.325 0 0 1531868.414

Story3 9 Top 1457339.764 0 0 1866914.282

Story2 6 Top 1886944.772 0 0 2287936.173

Story1 3 Top 2995238.902 0 0 2330725.839

Base 0 Top 0 0 0 0

Fig.27 Storey stiffness values of G+13 building with 0.32 SWA/FA% for EQ X




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TABLE 13


Story Elevation

m Location

For EQ X For EQ Y

X-Dir

kN/m

Y-Dir

kN/m

X-Dir

kN/m

Y-Dir

kN/m

Story13 39 Top 383512.536 0 0 276115.072

Story12 36 Top 796356.102 0 0 574927.648

Story11 33 Top 1130996.229 0 0 818840.394

Story10 30 Top 1405329.806 0 0 1019204.759

Story9 27 Top 1640468.36 0 0 1191414.591

Story8 24 Top 1855562.547 0 0 1349273.127

Story7 21 Top 2070186.806 0 0 1507264.195

Story6 18 Top 2307057.843 0 0 1682348.401

Story5 15 Top 2597815.179 0 0 1898706.21

Story4 12 Top 2993965.941 0 0 2194056.554

Story3 9 Top 3617318.461 0 0 2672107.227

Story2 6 Top 4469095.029 0 0 3282944.913

Story1 3 Top 4821186.821 0 0 2699681.493

Base 0 Top 0 0 0 0

Fig. 29 Storey stiffness values of G+13 building with 0.40 SWA/FA% for EQ X


D.Storey Shears

The below tables and graphs represents the relationship between storey vs. shears for different SWA/FA% of G+9 and G+13




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Fig.31 Storey shears of G+9 building with 0.48 SWA/FA% for EQ X

Fig.32 Storey shears of G+9 building with 0.48 SWA/FA% for EQ Y

Fig. 33 Storey shears of G+9 building with 0.31 SWA/FA% for EQ X

Fig. 34 Storey shears of G+9 building with 0.31 SWA/FA% for EQ Y



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V. CONCLUSIONS

On the basis of the results of the analytical investigation of 9 and 13 storey RC building models with increasing and decreasing

shear wall to floor area ratio (SWA / FA) % by considering the ground floor as open ground storey, the following conclusions are

drawn:

It is observed that as the height increases the displacements are also increases, but by increasing the SWA / FA % the

displacements values decreases. In case of 9 – storey building model maximum displacements are observed when SWA / FA

% = 0.31 and In case of 13 – storey building model when SWA / FA % = 0.32 maximum displacements are observed as

expected.

However, a shear wall ratio less than 0.31 % is not sufficient to limit the observed displacement. Similar effects can be seen in

nine storey model.

It is observed that there is a decrease in storey drift as the storey increases and also when the shear wall ratio is increased from

0.31 to 0.40% in G+13 building.

It is observed that there is a decrease in storey shear as the storey increases and increases when the shear wall ratio is increased.

In case of G+13 building when SWA/FA % = 0.31 the storey shears are more in Y-direction but as the SWA/FA % is increased

to 0.40% the storey shears are more in X-direction than in Y-direction.

It is observed that there is a decrease in storey stiffness as the storey increases and increases when the shear wall ratio is

increased.

The storey stiffness values are more in X-direction as compared to Y-direction.

G+9 and G+13 structures are stiffer for high SWA/FA% i.e., for 0.48% and 0.4% respectively.

REFERENCES

1. Riddell, R., Wood, S. L., and De La Llera, J. C. (1987). “The 1985 Chile earthquake, structural characteristics and damage statistics for the building inventory

in Vina del Mar.” Structural Research Series No. 534, Univ. of Illinois, Urbana, IL.

2. Wallace,J.W.(1994).“A new methodology for seismic design of reinforced concrete shears walls.” Journal of Structural Engineering 120(3), 863–884.

3. FINTEL, M. (1995) “Performance of buildings with shear walls in earthquakes of the last thirty years.” Journal of Structural Engineering 120(3), 863–884.

4. Hassan, A. F., and Sozen, M. A. (1997). “Seismic vulnerability assessment of low-rise buildings in regions with infrequent earthquakes.” ACI Journal of

Structural Engineering 94(1), 31–39.

5. Tekel, H. (2006). “Evaluation of usage of 1% shear wall in reinforced concrete structures.” Turkish Eng. News, 444–445 (2006/4–5), 57–63.

6. European Committee for Standardization. (2003). “Design of structures for earthquake resistance—Part 1: General rules, seismic actions and rules for

buildings.” Euro code 8, Brussels, Belgium.

7. Gulkan, P. L., and Utkutug, D. (2003). “Minimum design criteria for earthquake safety of school buildings.” Turkiye Muhendislik Haberleri, Sayi, 425(3), 13–

22.

8. Chai and Kunnat (2005) “Effect of shear walls on the behavior of reinforced concrete buildings under earthquake loading.” M.S. thesis, Middle East Technical

Univ., Ankara, Turkey.

9. Canbolat, B. B., Soydas, O., and Yakut, A. (2009). “Influence of shear wall index on the seismic performance of reinforced concrete buildings.” Proc., World Council of Civil Engineers - European Council of Civil Engineers - Turkish Chamber of Civil Engineers (WCCE-ECCE-TCCE) Joint Conf. (CD-ROM),

Tubitak, Ankara, Turkey

10. Sharany Haque, Khan Mahmud Amanat “Seismic Vulnerability of Columns of RC frames Buildings with Open ground ground Storey” Journal of Structural

Engineering.

11. Pacific Earthquake Engineering Research Center (PEER). (2009). “Strong motion database.”Http://peer.berkeley.edu/peer_ground_motion_database (Jan. 30,

2009).

12. IS -1893, “Criteria for Earthquake Resistant Design of Structures – Part I, General provisions and buildings (Fifth Revision)”. Bureau of Indian Standards, New Delhi, 2002.

13. Pankaj Agarwal and Manish Shrikhande, “Earthquake Resistant Design of Structures” PHI Learning Private Limited, New Delhi, 2010.

14. Taranath B.S., “Structural Analysis and Design of Tall Buildings” McGraw-Hill Book Company, 1988.

15. ETABS 9.5, “Documentation and Training Manuals”.



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EATHQUAKE RESISTANCE DESIGN OF OPEN GROUND STOREY BUILDING