comperative study of rc framed structure with …

e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science

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Volume:03/Issue:12/December-2021 Impact Factor- 6.752 www.irjmets.com

www.irjmets.com @International Research Journal of Modernization in Engineering, Technology and Science

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COMPERATIVE STUDY OF RC FRAMED STRUCTURE WITH VARYING

MOMENT OF INERTIA IN SEISMIC ZONE V

Chhagan Kumar Jangir*1, Dr. A. K. Dwivedi*2

*1M.Tech Scholar, Civil Engineering Department, University College Of Engineering,

Kota, Rajasthan, India.

*2Professor, Civil Engineering Department, University College Of Engineering, Kota, Rajasthan, India.

ABSTRACT

A structural design engineer should design the structure or any element of the structure in a way by that the

structural systems or any part of structure should be performing their functions satisfactory and at that time

the structure design should be proved economical. If the structure does not fulfil basic requirements of seismic

design may be suffered vast damage or collapse if shaken by severe ground motion. This helps to choose the

right type of sections consistent with the economy along with safety and serviceability of the structure.

Prismatic sections are commonly used for any beam sections and easy workability at site. As the span increases,

bending moments and shear forces increases significantly at the centre of the span and at the beam supports.

So, in such case the regularly prismatic beam sections are become uneconomical. additionally, with the

increasing in depth of prismatic beam as well as we find significantly decrease in headroom. Therefore, in such

cases, non-prismatic beams are an appealing solution.

Keywords: Prismatic Beams, Seismic Design, Shear Force, Bending Moment, Headroom Etc.

I. INTRODUCTION

In the present study, multi-story regular buildings with G+10 stories have been modelled and analysed by

Response Spectrum Method using software ETABS15.0.0. for seismic zone V in India. Response Spectrum is a

linear dynamic analysis. Response Spectrum is a plot of the maximum response of a single-degree of freedom

system to a ground motion versus period. To get more accurate results for comparison for response spectrum

we use different damping ratios. The seismic evaluation reflects the seismic capacity of earthquake vulnerable

buildings for future use. This helps to choose the right type of sections consistent with the economy along with

the safety and serviceability of the structure. Load on the slab is transferring through beams to the column in

the structure. A careful approach in its design may lead to good serviceability. In multi-storied buildings,

prismatic beams sections are generally used for medium span length. If the span length increasing, the bending

moments and shear force increasing substantially. accordingly, prismatic beams sections become uneconomical

due to in such cases. Moreover, with the increased depth there is a considerable decrease in headroom also

then in such cases non-prismatic beams are a better way to design the structure. The cross-section of the beams

can be made non-prismatic by varying width, depth or by varying both depth and width along their length. But

due to difficulty in construction execution, beam varying depth is generally provided. To find varying beam

section can be inclined the beam from top or bottom. The beam bottom generally has a triangular and parabolic

haunches shape. The effective depth of such beams varies from point to point and the internal compressive and

tensile stress resultants are inclined. It analyses such beams lightly diverse from prismatic beams.

II. LITERATURE REVIEW

In the order of study to the research paper about the prismatic and non-prismatic behaviours of the beam with

the help various methodology with the help of different software tools and know the concepts of analysis to

bare frame and frame with infill in seismic zone V. Also studied the papers about the effect of changes in various

earthquake parameters and analysis with using static and dynamic methods and find out the comparison

among on it.

A study by Jolly and Vijayan (2016)

In the beam, prismatic sections are widely used in medium length span. If the length of beams increases become

uneconomical due to an increase in depth. In such a situation, non-prismatic beams are a good solution. The

present study of the structural behaviour is studied by ANSYS and ETABS.





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A study by Nampalli and Sangave (2015)

This research paper studied linear and non-linear analysis of reinforced concrete buildings with members of

varying inertia. For a framed structure two methods are used for Linear analysis one is the Seismic Coefficient

Method and another is the Response Spectrum Method. The pushover analysis method is used as a Non-linear

analysis of frame structure in the study.

A study by Patil et al. (2013)

This paper describes the seismic analysis of high-rise building using the program in STAAD Pro. with various

conditions of lateral stiffness system. few models are drafted that is a bare frame structure, brace frame

structure and shear wall framed structure. This analysis is doing using appropriate tools of design with the

response spectrum method.

A study by Gulsan and Dhiman (2016)

In this study, seven types of buildings are taken for analysis, out of which one is a regular building and the rest

are buildings with setbacks at different storey height. Regular structures are compared with all types of

irregular structure based on various parameters like shear force, bending moment and axial forces at setbacks.

It appears that the value of axial force in all beams and columns are increasing drastically as we move from

regular to irregular structure.

A study by Kolekar et al. (2017)

The paper studied that dynamic analysis of G+12 reinforced concrete multi-storied framed building considering

for Koyna and Bhuj earthquake is done by two methods are- response spectrum analysis and time history

analysis. The comparative study of the project done with the help of SAP2000 software.

A study by Hawaldar and Kulkarni (2015)

In the present work G+12, a storey building model with infilled wall frame and without infill is considered and

the time history analysis considering for Bhuj and Koyna earthquake functions are carried out in ETABS 2013

software.

A study by Ramakrishna, Reddy and Riyaz (2017)

In this paper seismic response of a residential G+10 RC frame building is analysed by the linear analysis

approaches of Equivalent Static Lateral Force and Response Spectrum methods using ETABS 2015 software as

per the IS- 1893-2002-Part-1. These analyses are carried out by considering different seismic zones, medium

soil. Different results are found like lateral force, drift, displacements, base shear etc and comparison of the

outcomes of static lateral force and response spectrum method.

III. RESPONSE SPECTRUM METHOD

In the analysis of any type structures cannot be performed simply based on the peak value of the ground

acceleration as the response of the structure depends upon the frequency content of ground motion and its

dynamic properties. To overcome the above difficulties, the earthquake response spectrum is the most popular

tool in the seismic analysis of structures. There are computational advantages in using the response spectrum

method of seismic analysis for prediction of displacements and member forces in structural systems. The

method involves the calculation of only the maximum values of the displacements and member forces in each

mode of vibration using smooth design spectra that are the average of several earthquake motions.

Response spectrum method is an important tool in the seismic analysis and design of structures. It describes

the maximum response of damped single degree of freedom system to a particular input motion at different

natural periods. Response spectrum method of analysis is advantageous as it considers the frequency effects

and provides a single suitable horizontal force for the design of the structure. This method is also known as

Modal Method or Mode Super-Position Method.

In the linear dynamic methods, the building is modelled as a single degree of freedom (SDOF) system with a

linear elastic stiffness matrix and an equivalent viscous damping matrix. The seismic input is modelled using

either modal spectral analysis the corresponding internal forces and displacements are determined using linear

elastic analysis. The advantage of these linear dynamic procedures concerning linear static procedures is that

higher modes can be considered. The damping value for a building is taken 2% and 5% for the critical, for





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dynamic analysis of steel frame structure and reinforced concrete structure respectively. In linear dynamic

analysis, the performance of the structure to ground movements is presented in way of time domain. Some

properties of the frame are assumed. This analysis method can used in decomposition of model as a way

reduced the amount of freedom in the method. Static methods procedure is suitable when higher mode effects

are not suitable. Commonly, this is good for short frames and regular structures. so, for other types of

structures like - tall structures, frames with torsional irregularities effects, a dynamic analysis method is

necessary for that structures.

3.1 Load Combinations:

For limit state design of the reinforced structure, the following load combinations should be accounted for.

Here, 1.5, 1.2 and 0.9 are the safety factors considered.

1) 1.5(DL+LL)

2) 1.2(DL+IL+EL)

3) 1.2(DL+IL-EL)

4) 1.5(DL+EL)

5) 1.5(DL-EL)

6) 0.9DL+1.5 EL

7) 0.9DL-1.5 EL

IV. MODELLING AND ANALYSIS

4.1 Structural Modelling and Properties: -

The reinforced concrete ordinary moment-resisting frame structure modelled using ETABS15.0.0 software and

analyse the structure for different variables like prismatic and non-prismatic framed structure. Define the

structural modelling, material properties and IS code specifications are in tabulated form as follows:

S.No. Specification of Building Data

1 Storey height 4m

2 Depth of foundation 2m

3 Bays in the x-direction 1

4 Bays in the y-direction 6

5 Bay length along the x-direction 12m

6 Bay length along the y-direction 4m

7 Concrete grade M30

8 Steel grade Fe415

9 Column 0.3 m x 0.75 m

10 Beam 0.3 m x 0.75 m

11 Slab thickness 150 mm

12 Wall thickness 230 mm

13 Unit weight of concrete 25 KN/m3

14 Unit weight of steel 7850 KN/m3

15 Unit weight of masonry 20 KN/m3

16 Seismic zone V

17 Zone factor 0.36

18 Soil condition Medium

19 Damping 3%, 4% and 5%





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20 Response reduction factor (R) 3

21 Importance factor (I) 1

22 Live load 3.5 KN/m2

23 Floor finish load 1.5 KN/m2

24 Masonry load 14.95 KN/m2

25 No. of floor or storey G+10

Figure 4.1: Plan of Bare Frame Structure

Figure 4.2: Plan of Frame with Infill





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Figure 4.3: Elevation of Bare Frame in the Y direction

Figure 4.4: Isometric view of structure with Infill after applying Masonry Load





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Figure 4.5: Isometric view of structure with Prismatic Beam in Frame with Soft Storey

Figure 4.6: Isometric view of structure with Linear Haunch Beam in Frame with Infill





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Figure 4.7: Isometric view of structure with Stepped Haunch Beam in Bare Frame

4.2 Structural Analysis Flowchart using Etabs15.0.0 Software:

Following steps are used for structure analysis of by using Etabs15.0.0 software:

Step 1. Define Model Case Data

Step 2. Define Response Spectrum Functions

Step 3. Load Case Data

Step 4. Define Response Spectrum Load Pattern

Step 5. Set Load Case to Run Analysis

V. RESULTS

The response spectrum analysis method is executed by using ETABS 15.0.0 software. The response of structure

has been analysed and presented it by base shear and top storey displacement. The results of several variables

are presented in by way of numerical data as shown figures from fig. 5.1 to fig. 5.12. The observations for each

parametric variation are stated as under following tables and graphs.

5.1 Base Shear (KN): It is the estimated total design lateral force at the base of the structure due to seismic

activity at ground. Here we compare the results of Base Shear in the X direction, as well as Y-direction. Base

Shear variations the X direction and Y direction for G+10 building is shown from Fig. 5.1 to 5.6.





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Figure 5.1: Variations of Base Shear in the X direction for Bare Frame in KN

Figure 5.2: Variations of Base Shear in the Y direction for Bare Frame in KN

Figure 5.3: Variations of Base Shear in the X direction for Frame with Infill in KN

3730.14 4114.95 4290.01

3344.14 3688.71 3845.4

2958.05 3262.39 3400.7

0500

100015002000250030003500400045005000

Linear Haunch Stepped Haunch

Frame with Prismaticmember

Frame with non prismatic member

Ba

se S

he

ar

(kN

)

Types of Model Damping Damping Damping

3425.24 3434.44 3441.96 3071.59 3079.59 3086.22

2717.36 2724.31 2730.13

0

500

1000

1500

2000

2500

3000

3500

4000




Bas

e Sh

ear(

KN

)

Types of Model

Damping Damping Damping

16283.95 16339.14 16394.22

14661.65 14710.94 14760.35

13028.95 13072.39 13116.14

0

2000

4000

6000

8000

10000

12000

14000

16000

18000




Ba

se S

he

ar(

KN

)

Types of Model






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Figure 5.4: Variations of Base Shear in the Y direction for Frame with Infill in KN

Figure. 5.5: Variations of Base Shear in the X direction for Frame with Soft Storey in KN

Figure. 5.6: Variations of Base Shear in the Y direction for Frame with Soft Storey in KN

12510.02 12550.95 12591.52 11208.02 11244.65 11280.94

9903.55 9935.85 9967.88

0

2000

4000

6000

8000

10000

12000

14000




Ba

se S

he

ar(

KN

)

Types of Model


17980.45 18014.6 18045.59 16088.47 16119.03 16146.76

14196.5 14223.46 14247.93

02000400060008000

100001200014000160001800020000


Frame with Prismatic

member


Ba

se S

he

ar(

KN

)

Types of Model


9638.08 9652.85 9667.58 8623.55 8636.77 8649.94

7609.01 7620.68 7632.3

0

2000

4000

6000

8000

10000

12000




Ba

se S

he

ar(

KN

)

Types of Model






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5.2 Top Storey Displacements (MM): It is the lateral displacement on the maximum level of the building

frame. The displacements are found for pushover x and pushover y. The deviations of displacements for G+10

frame building is shown in Figures 5.7 to 5.12.

Figure. 5.7: Variations of Displacement in the X direction for Bare Frame in mm

Figure. 5.8: Variations of Displacement in the Y direction for Bare Frame in mm

Figure. 5.9: Variations of Displacement in the X direction for Frame with Infill in mm

245 216.7 208.4 219.1

193.8 186.5 193.1 170.8 164.4

0

50

100

150

200

250

300




Dis

pla

cem

en

t in

mm

Types of Model


272.1 272.3 273.1 243.2 243.5 244

214.3 214.7 215

0

50

100

150

200

250

300




Dis

pla

cem

en

t in

mm

Types of Model


0.892 0.892 0.892

0.654 0.654 0.654

0.441 0.441 0.441

0

0.2

0.4

0.6

0.8

1



member


Dis

pla

cem

en

t in

mm

Types of Model






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Figure. 5.10: Variations of Displacement in the Y direction for Frame with Infill in mm

Figure. 5.11: Variations of Displacement in the X direction for Frame with Soft Storey in mm

Figure. 5.12: Variations of Displacement in the Y direction for Frame with Soft Storey in mm

0.0937 0.0937 0.0937 0.0838 0.0838 0.0838

0.0735 0.0735 0.0735

00.010.020.030.040.050.060.070.080.09

0.1



member


Dis

pla

cem

en

t in

mm

Types of Model


53 53 53 47.2 47.2 47.2

41.9 41.9 41.9

0

10

20

30

40

50

60


Frame with Prismatic member Frame with non prismatic member

Dis

pla

cem

en

t in

mm

Types of Model


87.1 87.2 87.3 78.5 78.6 78.7

69 69.1 69.2

0102030405060708090

100




Dis

pla

cem

en

t in

mm

Types of Model






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VI. CONCLUSION

In this study, we get the results of the frame structure is performed with varying inertia of beam for storey

height G+10. Further, three cases are considered of the beam. The buildings are analysed for various damping

ratios and comparisons done between several parameters like base shear, top storey displacement, storey

shear, storey drift and reactions. From the analysis results conclusions are as follows: -

1. Base Shear: - From the results of analysis, we observed that bending moment is maximum in the building

having infill wall. Frame with the soft storey in both the x-direction and y-direction to comparison with the

amount of shear of Prismatic member to Linear Haunch varies from 0.15 to 10.31% and Stepped Haunch is

varying from 0.31 to 15.00%, but with the increase in damping for 3% to 4% in the amount of shear is

decreasing varies from 10.34% to 10.64% and damping for 4% to 5% in the amount of shear decreasing varies

from 11.13% to 11.76% for all type members.

2. Top Storey Displacement: - From the comparison, we observed that the bending moment is maximum in

the building having an infill wall. Frame with the soft storey in both the x-direction and y-direction to

comparison with the value of displacement of Prismatic member to Linear Haunch varies from 0.0 to 11.55%

and Stepped Haunch is varying from 0.0 to 14.94%, but with the increase in damping for 3% to 4% the value of

displacement 78 is decreasing varies from 9.87% to 26.68% and damping for 4% to 5% the value of

displacement decreasing varies from 11.22% to 32.56% for all type members.

VII. REFERENCES [1] Prerana Nampalli, Prakash Sangave “Linear and Non-Linear Analysis of Reinforced Concrete Frames

with Members of Varying Inertia” IOSR Journal of Mechanical and Civil Engineering,2015.

[2] Chopra AK. Dynamics of Structures: theory and applications to earthquake engineering. Englewood

Cliffs, NJ; 1995.

[3] Wakchaure M.R, Ped S “Earthquake Analysis of High Rise Building with and Without Infilled Walls”,

International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue,.2012.

[4] Anu Jolly, VidyaVijayan “Structural Behaviour of Reinforced Concrete Haunched Beam” International

Journal of Scientific & Engineering Research, Volume 7, Issue 10, October-2016.

[5] Ajay Singh Gulshan1, Poonam Dhiman2 “Response Spectrum Analysis of Response of Building with

Setbacks” IOSR Journal of Mechanical and Civil Engineering (IOSRJMCE).

[6] Jyothi. C. Hawaldar, Dr. D. K. Kulkarni “Earthquake Analysis of A G+12 Storey Building With And

Without Infill For Bhuj And Koyna Earthquake Functions” International Research Journal of

Engineering and Technology (IRJET).

[7] Atul.N Kolekar et.al. “Comparative study of Performance of RCC Multi-Storey Building for Koyna and

Bhuj Earthquakes” Int. Journal of Engineering Research and Application ISSN: 2248- 9622, Vol. 7, Issue

5, ( Part -2) May 2017.

[8] K. Ramakrishna Reddy, Dr. S. Vijaya Mohan Rao “Seismic Analysis of High Raised Building by Response

Spectrum Method” International Journal of Advanced Technology and Innovative Research (IJEIT) ISSN

2348–2370 Vol.08, Issue.21, November-2016.

[9] Sopna Nair, Dr. G Hemalatha and Dr. P Muthupriya “ Response Spectrum Analysis And Design Of Case

Study Building” International Journal of Civil Engineering and Technology (IJCIET) Volume 8, Issue 8,

August 2017.

[10] Prof. S.S. Patil et al. “Seismic Analysis of High-Rise Building by Response Spectrum Method”

International Journal Of Computational Engineering Research Vol. 3 Issue. 3

[11] Etabs User’s Manual, “Integrated Building Design Software”, Computer and Structures Inc. Berkeley,

USA.

[12] ATC-40, Seismic evaluation, and retrofit of concrete buildings, Applied Technology Council, November

1996.

[13] FEMA-356, Prestandard, and commentary for seismic rehabilitation of buildings Federal Emergency

Federal Agency Washington DC, 2000.

[14] Karwar, Londhe “Performance of RC framed Structure by using Pushover Analysis” International

Journal of Emerging Technology and Advanced Engineering,2014.





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[15] Pankaj Agrawal, Manish Shrikhande, ‘Earthquake Resistant Design of Structures’, Prentice- Hall India

Publication.

[16] I.S. 456-2000, Indian standard code of practice for plain and reinforced concrete (4th Revision), Bureau

of Indian Standards, New Delhi.

[17] I.S. 1893 (Part-1)-2002, Criteria for earthquake resistant design of the structure, general provision, and

building, Bureau of Indian Standards, New Delhi.

comperative study of rc framed structure with …

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