CAPACITY SPECTRUM ME THOD ON RCC AND COMP OSITE …...4 Column section ISHB 450 5 Beam section ISWB...

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International Journal of Civil Engineering and Technology (IJCIET)Volume 8, Issue 5, May 2017, pp.

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ISSN Print: 0976-6308 and ISSN Online: 0976

© IAEME Publication

CAPACITY SPECTRUM ME

COMPOSITE FRAME STRUCTUR

Postgraduate student,

VIT University, Chennai

Asst.professor (Sr.)

VIT University, Chennai

ABSTRACT

Buildings are affected severely during the earthquake. While design the any

building in seismic zone, earthquake load are to be considered. To know the behavior

of structures under seismic load there are three methods namely push over analysis,

Time history analysis and Response Spectrum analysis. Based on the required result

the type of method is performe

capacity spectrum method techniques is implemented. The Capacity Spectrum

Method[CSM] is a performance based seismic design techniques and it is obtained by

non-linear force – displacement curve know

accepted displacement based seismic design by means of graphical procedure

,comparing the structure capacity with respect to ground motion of the structure. The

roof displacement and base shear forces are converted to eq

acceleration and spectral displacement with respect to coefficient that shows the

effective model masses and model participation factor. This spectral values defines

the capacity spectrum of both structure.

RCC and Composite frame structure with irregular plan.

design of sixteen storied framed structure is be done by using non

pushover analysis in ETABS Software.

Key words:-Steel, RCC, composite structure, sei

Cite this Article: ChBhupal Reddy and K Vasugi Capacity Spectrum Method on Rcc

and Composite Frame Structures

Technology, 8(5), 2017, pp.

http://www.iaeme.com/IJCIET/issues.

IJCIET/index.asp 73 [email protected]

International Journal of Civil Engineering and Technology (IJCIET) 2017, pp.73–85, Article ID: IJCIET_08_05_010

http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=8&IType=5

6308 and ISSN Online: 0976-6316

Scopus Indexed

CAPACITY SPECTRUM METHOD ON RCC AND

OSITE FRAME STRUCTUR

ChBhupal Reddy

student, School of Mechanical and Building Sciences,

VIT University, Chennai, Tamilnadu.

K Vasugi

(Sr.), School of Mechanical and Building Sciences,

VIT University, Chennai, Tamilnadu.


earthquake load are to be considered. To know the behavior



the type of method is performed. In this research the push over analysis is chosen and



displacement curve know as push over analysis.



roof displacement and base shear forces are converted to equivalent spectral



the capacity spectrum of both structure. This paper present the seismic e

RCC and Composite frame structure with irregular plan.Analysis and connection

design of sixteen storied framed structure is be done by using non

pushover analysis in ETABS Software.

, composite structure, seismic analysis, capacity spectrum.

ChBhupal Reddy and K Vasugi Capacity Spectrum Method on Rcc

and Composite Frame Structures. International Journal of Civil Engineering and

, 8(5), 2017, pp. 73–85.

http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=8&IType=5

[email protected]

asp?JType=IJCIET&VType=8&IType=5

THOD ON RCC AND

OSITE FRAME STRUCTURES

School of Mechanical and Building Sciences,

of Mechanical and Building Sciences,


earthquake load are to be considered. To know the behavior



d. In this research the push over analysis is chosen and



as push over analysis. It is widely



uivalent spectral



This paper present the seismic evaluation of

Analysis and connection

design of sixteen storied framed structure is be done by using non-liner static

smic analysis, capacity spectrum.

ChBhupal Reddy and K Vasugi Capacity Spectrum Method on Rcc

International Journal of Civil Engineering and

asp?JType=IJCIET&VType=8&IType=5

Capacity Spectrum Method on Rcc and Composite Frame Structures

http://www.iaeme.com/IJCIET/index.asp 74 [email protected]

1. INTRODUCTION

Capacity spectrum method (CSM) is defined as the ratio of spectral acceleration and spectral

displacement. It was initially introduced by freeman in 1970’s. This is one of the seismic

design procedure to find the correlation between building performance and earthquake

ground motions (ATC 40).this method is also used in the performance based seismic analysis

for various steel and reinforced cement concrete structures. The design procedure compares

the structure capacity (in the form of push over curve) with the structure demands (in the

form of response spectra).The response of the structure is find from intersecting of the two

curves. The capacity spectrum method is also used to verify the design procedure of new

buildings and commercial buildings. For damage identification purposes also this method is

used and this method is also called as nonlinear static push over analysis by changing the base

shear in x-axis and roof displacements in y-axis from a non-liner static push over analysis to

equivalent spectral accelerations and spectral displacements. From that capacity curve we

find the maximum displacements and performance point of the structure.

Reinforced cement concrete construction is one of the famous construction in the world.

This is widely used for the commercial and industrial buildings by using the steel bars in

plain concrete to overcome the tensile strength of the buildings. Concrete is strong in

compression and weak in tension as well as steel reinforcement is strong in tension and weak

in compression, by combining (or) by adding this two materials i.e. concrete and steel gives

the good results. For the modern constructions and special design constructions this RCC is

used. The workability and durability of the concrete is high.

The term which we are used for any building construction by adding multiple dissimilar

materials is known as composite construction. Few years back composite materials are used

in industrial buildings now a days this materials are using in residential buildings also.

Composite structures are defined as the combination of two different materials which they are

used in column or beam or slab. They are several reasons behind using this composite

materials, it increases the strength, durability and environmental sustainability. Few years ago

Composite constructions dominates the residential building sectors by using this composite

materials weight of the building is less and stiffness is more .utilizing this composite

constructions provide the significant benefits in terms of building envelope and cost of

services .

Steel connections form a crucial part in any type of steel structures. This connections are

more complicated then members to design and analysis. The type of connection is depends on

the structural member and weight of the building. The different type of components used in

the connection elements are gusset plates, cleats, and brackets. Connectors for the connection

plates such as bolts, pins, rivets and weld.

2. LITERATURE REVIEW

Shweta A. Wagh and Dr. U. P. Waghe[4]conclude that the stiffness and durability of the

composite structures are strong compare to RCC structure. Under earthquake conditions

composite steel section is strong compare to RCC structure. Lifting, placing and fixing the

elements is much faster than RCC structures. When compare to RCC structure the total

building cost of the composite structures is higher, by using lighter sections in composite

construction reduces the self-weight of the building and reduces the total cost of the building.

V.Vysakh, Dr. Bindhu and K.R. Rahul Leslie [5] et all concludes that two different type of

procedure they followed i.e program based procedure and another one is simplifying

assumptions that is yield stress put it as constant. The displacement values in procedure B are

more than procedure A. the difference between spectral acceleration and spectral


displacement values with respect to both the design procedures are 7.28% and 6.28%

respectively. The difference between two design procedures for four story building

Tiziana Rossetto et all [6] conclude that capacity spectrum assessment is one of the method

used in finding the ground accelerations through fragility capacity spectrum assessment

(FRACAS). From the analysis of the structure finding the fragility

non-linear time history analysis (NLTHA).in this paper they find how the in elastic record to

record date is converting in to fragility curves. The static push over curves are derived from

the fragility curves and the difference

spectra and target spectra respectively.

Karim Tarbali, and Kazem Shakeri

ST-ACS methods. The response of this two higher story methods are approx

The estimation result of the ST

stories of the structure. The adaptive capacity spectrum method cannot give the better

estimation results compare to different load varying of the struct

MPA method ST-ACS method gives the higher or equal estimation results. For high rise

buildings MPA method is more suitable to estimate the results. Story drift values are used to

evaluate the damage stage of the buildings subjected t

3. DETAILS OF SECTION

3.1. Capacity Spectrum Method

This is one of the method used to find the correlation between spectral acceleration in y

and spectral displacement in x

demand curve) they meet at single point that point called as performance

building. The maximum displacement of the structure get from pushover analysis. This

analysis gives the accurate and exact values of the struct

Figure 1 Capacity

3.2. Composite Frame

The section which made with the combination of two different type of materials such as steel

and concrete used in columns and beams is known as composite frame structures.

floor slab: The most common floor system is built

steel deck is connected to the beam section and struts are used at the top of the steel deck

connected to beam and concrete is poured at the top of the steel deck. The thickness of the

composite slab is less compare to

shallow decking the thickness of the

ChBhupal Reddy and K Vasugi



respectively. The difference between two design procedures for four story building

[6] conclude that capacity spectrum assessment is one of the method


(FRACAS). From the analysis of the structure finding the fragility curves and compare to the

linear time history analysis (NLTHA).in this paper they find how the in elastic record to


the fragility curves and the difference between two curves are represents in the form of input

spectra and target spectra respectively.

Karim Tarbali, and Kazem Shakeri [7] conclude that compare the estimations from ST and

ACS methods. The response of this two higher story methods are approx

The estimation result of the ST-ACS method is nearly equal to the NHRA result in bottom


estimation results compare to different load varying of the structure. When comparing to

ACS method gives the higher or equal estimation results. For high rise


evaluate the damage stage of the buildings subjected to ground accelerations.

DETAILS OF SECTION

Spectrum Method

This is one of the method used to find the correlation between spectral acceleration in y

spectral displacement in x-axis by combining the two curves (i.e. spectrum curve and

demand curve) they meet at single point that point called as performance


analysis gives the accurate and exact values of the structure compare to other analyses.

Capacity Spectrum Curve for Identification [3]


and concrete used in columns and beams is known as composite frame structures.

floor slab: The most common floor system is built-up section (or) rolled steel section and the



composite slab is less compare to the rcc slab. The self-weight of the slab is also less. For the

shallow decking the thickness of the slab in the range 100 to 250 mm for the deep decking the

[email protected]


respectively. The difference between two design procedures for four story building is 22mm.

[6] conclude that capacity spectrum assessment is one of the method


curves and compare to the

linear time history analysis (NLTHA).in this paper they find how the in elastic record to


between two curves are represents in the form of input

conclude that compare the estimations from ST and

ACS methods. The response of this two higher story methods are approximately equal.

ACS method is nearly equal to the NHRA result in bottom


ure. When comparing to

ACS method gives the higher or equal estimation results. For high rise


o ground accelerations.

This is one of the method used to find the correlation between spectral acceleration in y-axis

by combining the two curves (i.e. spectrum curve and

demand curve) they meet at single point that point called as performance point of the


ure compare to other analyses.


and concrete used in columns and beams is known as composite frame structures. Composite

on (or) rolled steel section and the



weight of the slab is also less. For the

for the deep decking the



slab thickness in the range 250 to 320mm.

composite frame sections.

Figure 2 Composite Floor Slab for Identification [Wiki]

3.3. Steel Connections

Steel connections are generally used in steel frame constructions and industrial constructions.

They are different type of connections used for steel

connections are welded connections, bolted connections and riveted connections. In that

welded connections fillet weld is mostly used in all type structures. Bolted connections are

used in frame section for resisting th

bolted connections are used to transfer the force in both

this paper mainly focusing on the beam to beam and column to column connection in

composite frame structures.

Figure 3 Bolted connections for Beam

4. BUILDING DETAILS

In this research work the building is consider as a commercial building. The plan dimensi

of the structure is 22mX12m.

frame structure. The basic loading conditions for both the structures are kept as same

IS 1893-2002 time period of the building has calculated.



slab thickness in the range 250 to 320mm. There is no separate Indian code for the design of

Composite Floor Slab for Identification [Wiki]


They are different type of connections used for steel constructions. The different type of



used in frame section for resisting the moments in column –beam sections. The concentric

bolted connections are used to transfer the force in both tension and compression members


Bolted connections for Beam-Beam and Beam-column [wiki]

BUILDING DETAILS

In this research work the building is consider as a commercial building. The plan dimensi

. This plan dimensions are same for both RCC and

frame structure. The basic loading conditions for both the structures are kept as same

2002 time period of the building has calculated.


[email protected]

here is no separate Indian code for the design of


constructions. The different type of



beam sections. The concentric

tension and compression members in


[wiki]

In this research work the building is consider as a commercial building. The plan dimensions

his plan dimensions are same for both RCC and composite

frame structure. The basic loading conditions for both the structures are kept as same as per



Figure 4 Overview Plan of RCC structure

Table 1 Parameters Used for RCC Framed Structures

S.NO DESCRIPTION DETAILS

1 Length X width 22 mX12 m

2 No.of storey’s 16(G+15)

3 Each floor height 3 m

4 Column size 0.7 mX0.7 m

5 Beam size 0.7 mX0.45 m

6 Slab thickness 0.15 m

7 Shear wall thickness 0.200

8 Live load on floors 3 KN/m2

9 Live load on roof 1.5 KN/m2

10 Seismic zone III

11 Response reduction factor 5

12 Soil type Medium

13 Importance factor 1

14 Grade of concrete M30

15 Zone factor 0.16

16 Time period 1.365 sec

17 damping 5%

Figure 5 Overview Plan of composite framed structure



Table 2 Parameters used for Composite Framed Structure

S.NO DESCRIPTION DETAILS

1 Length X Width 22 mX12 m

2 No.of store’s 16(G+15)

3 Each floor height 3 m

4 Column section ISHB 450

5 Beam section ISWB 400

6 Slab thickness 0.10

7 Live load on floors 3 KN/m2

8 Live load on roof 1.5 KN/m2

9 Seismic zone III

10 Response reduction factor 5

11 Soil type Medium

12 Importance factor 1

13 Grade of concrete M30

14 Zone factor 0.16

15 Time period 1.476 sec

16 Damping 5%

5. MODELING OF STRUCTURE

In the present research work a sixteen storied RCC and composite frame structure situated in

zone III, is taken for the research work. The plan dimensions for both the structures is

22mX12m with 3m height of each story. The total height of the building is 48m and it is an

asymmetrical building. The soil condition of the building should consider as a medium. In the

composite constructions column-beam connections should also be consider for analysis.

Figure 6 3D view of RCC and Composite Framed Structures


5.1. Diaphragm of the Structures

This is one of the technique used in the f

diaphragm on the structure all the loads acting at the centre of gravity and these

to the basement of the structure.

Figure 7 Diaphragm of the

6. RESULTS AND DISCUSSI

The 3-dimensional building model is analyzed by using equivalent static method in ETABS.

Seismic codes are required for analyzing any type of structures. In this research work using

IS1893-2002 code for seismic calculations as well as manual lateral load calculations. For

analyzing the RCC Structures using IS 456

loads all type of structures.

6.1. Displacement

It is observed that the displacement values of the composite frame structure higher as

compare to RCC frame structure. The displacement values of both the structures with in the

limit as per 1893-2000. The v

figure 8 at each stories with a final difference of 17mm (Top).



of the Structures

This is one of the technique used in the frame analysing for good results

diaphragm on the structure all the loads acting at the centre of gravity and these

to the basement of the structure.

Diaphragm of the RCC and Composite Frame Structures

RESULTS AND DISCUSSIONS

dimensional building model is analyzed by using equivalent static method in ETABS.

for analyzing any type of structures. In this research work using

2002 code for seismic calculations as well as manual lateral load calculations. For

analyzing the RCC Structures using IS 456-2000 code and IS 875 part III is using for wind

is observed that the displacement values of the composite frame structure higher as


2000. The variation in displacement of both the structure are shown in

at each stories with a final difference of 17mm (Top).

[email protected]

rame analysing for good results by applying the

diaphragm on the structure all the loads acting at the centre of gravity and these loads transfer

nd Composite Frame Structures

dimensional building model is analyzed by using equivalent static method in ETABS.

for analyzing any type of structures. In this research work using

2002 code for seismic calculations as well as manual lateral load calculations. For

2000 code and IS 875 part III is using for wind

is observed that the displacement values of the composite frame structure higher as


tructure are shown in the



Figure 8 Displacement graph of RCC and Composite Framed Structures

6.2. Time Period

Based on the previous earthquake, the frequency values are taken according to IS 1893-2002

part 1 and it shows the damping values at particular time period. According to that damping

values. The oscillation of the building with different time period are taken. Time period

values are given in table 3.

Table 3 Time period of RCC and Composite frame structure

S.NO MODE

NUMBERS

TIME PERIOD (Sec)

RCC FRAMED

STRUCTURE

COMPOSITE

FRAMED

STRUCTURE

1 MODE 1 0.921 0.939

2 MODE 2 0.908 0.825

3 MODE 3 0.780 0.782

4 MODE 4 0.284 0.424

5 MODE 5 0.27 0.41

6 MODE 6 0.248 0.275

7 MODE 7 0.154 0.237

8 MODE 8 0.14 0.194

9 MODE 9 0.137 0.169

10 MODE 10 0.105 0.133

11 MODE 11 0.094 0.132

12 MODE 12 0.092 0.119

0

10

20

30

40

50

60

70

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6

DIS

PLA

CE

ME

NT

(M

M)

NUMBER OF STOREYS

RCC COMPOSITE



The Time period values shows that Composite frame structure are almost similar to the RCC

frame structure. The sum of the damping percentage of both the structure is 95.6% which

shows the structure is safe under seismic load as per IS 1893-2002.

6.3. RCC Structure Analysis

6.3.1. Pushover curve

Push over analysis is done to carry out the accurate value of base shear and displacement

values. The curve plotted between base shear in y-axis and displacement in x-axis. This is one

of the method used to find the base shear and displacement values. For the capacity spectrum

method acceleration is calculated manually.

Acceleration =1.36 *(Z/2)

= 0.108 m/s2

Where

Z= zone factor=0.16

Base shear of the RCC frame structure is 1804 kN with a displacement of 31.6mm

Figure 9 Push over curve of RCC structure

6.3.2. Demand Spectra Curve

This method is used to find the maximum resistance of a building to resist displacement at

which lateral forces applied. This result are carried out by pushover analysis. This curve

plotted between spectral displacement and time period as shown in fig 10 .Spectral

displacement point is Sa =50.606 mm and Periodic time =0.782 sec.



Figure 10 Demand Spectrum Curve of RCC Structure

6.3.3 Performance point of the structure

The meeting of capacity curve and demand curve is called performance point. The curve

plotted between spectral displacement and spectral acceleration on are shown in Fig 11.The

performance point of the structure is 50.892mm, 0.332m/sec2.

Figure 11 Performance Point of the RCC Structure

6.4. Composite Frame Structure Analysis:

6.4.1. Push over Curve of Composite Frame Structure

The curve plotted between base shear in y-axis and displacement in x-axis. This is one of the

method used to find the base shear and displacement values. For the capacity spectrum

method acceleration is calculated manually as 0.108 m/s2.The maximum displacement of the

structure by applying pushover analysis is 35.6mm as shown in fig 12.


Figure 12

6.4.2. Demand Spectra Curve

This curve plotted between spectral displacement and time

displacement point is Sa =202.30 mm and Periodic time =1.28 sec

Figure 13 Capacity Spectra Curve of Composite Frame Structure

6.4.3. Performance Point of the Structure

The curve plotted between spectral displacement and spectral acceleration on are shown in

Fig 11. The performance point of the structure is



Pushover Curve of Composite Frame Structure

Demand Spectra Curve

This curve plotted between spectral displacement and time period as shown in fig 13.

=202.30 mm and Periodic time =1.28 sec.

Capacity Spectra Curve of Composite Frame Structure

Performance Point of the Structure


ance point of the structure is 202.30mm, 0.49m/sec2.

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shown in fig 13. Spectral

Capacity Spectra Curve of Composite Frame Structure




Figure 15 Performance Point of the Composite Framed Structure

6.5. Result comparison of RCC and Composite structure

From graphs 8 & 9 the displacement values of composite frame structures is higher compare

to RCC frame structure in both the

Composite frame structures got similar values

only. Then it’s safe for the structure to do

single demand curve meet at one point that point called performance point of structure. The

Performance Point of the composite frame structures is very high compare to the RCC frame

structure.

7. CONCLUSIONS

Analysis and design verification of sixteen storied framed structure can be done by using non

liner static pushover analysis. Conclude the all results of both RCC and composite framed

structures below.

• Under seismic load conditions composite frame are having higher displacement

• Spectral displacement for RCC framed structure is less when compared to composite

structure.

• The performance point of the composite frame structure is higher as compare to RCC

frame structure.

• RCC structure gives the better results compare to composite

• At last, I conclude that as both the structure is safe in seismic zone ; as compare speed of

construction is less time taken in composite structure as compare to RCC frame structure.



Performance Point of the Composite Framed Structure

of RCC and Composite structure:

graphs 8 & 9 the displacement values of composite frame structures is higher compare

to RCC frame structure in both the directions. The time period values of both RCC and

Composite frame structures got similar values. Sum of all the time period values less than

. Then it’s safe for the structure to do analysis. From fig 12 &15 the capacity curve and


Point of the composite frame structures is very high compare to the RCC frame

rification of sixteen storied framed structure can be done by using non


Under seismic load conditions composite frame are having higher displacement

Spectral displacement for RCC framed structure is less when compared to composite

The performance point of the composite frame structure is higher as compare to RCC

RCC structure gives the better results compare to composite frame structure.

At last, I conclude that as both the structure is safe in seismic zone ; as compare speed of



[email protected]

Performance Point of the Composite Framed Structure

graphs 8 & 9 the displacement values of composite frame structures is higher compare

time period values of both RCC and

of all the time period values less than one

15 the capacity curve and


Point of the composite frame structures is very high compare to the RCC frame

rification of sixteen storied framed structure can be done by using non-


Under seismic load conditions composite frame are having higher displacements.

Spectral displacement for RCC framed structure is less when compared to composite

The performance point of the composite frame structure is higher as compare to RCC

frame structure.

At last, I conclude that as both the structure is safe in seismic zone ; as compare speed of




REFERENCES

[1] “IS:1893 (Part 1), (2002), Criteria for earthquake resistant design of structures General

provisions and buildings”, Bureau of Indian Standards, New Delhi.

[2] “IS:800-2007 General construction in steel — code of practice”, Bureau of Indian

Standards, New Delhi.

[3] “IS:875 (Part 3), (1987), Code of practice for design loads for buildings and structures,

dead loads, Bureau of Indian Standards”, New Delhi.

[4] Shweta A. Wagh and Dr. U. P. Waghe “comparativestudy of RCC nd composite steel

fram structures”international journal of engineering and applications in the year 2014.

[5] Phu-Cuong Nguyen and Seung-Eock Kim “Nonlinear inelastic time-history analysis of

three-dimensional semi-rigid steel frames”journl of engineering structures in the year

2014.

[6] Tiziana Rossetto et all “FRACAS: A capacity spectrum approach for seismic fragility

assessment including record-to-record variability” journal of engineering structures in the

year 2015.

[7] Karim Tarbali and Kazem Shakeri “Story shear and torsional moment-based pushover

procedure for asymmetric-plan buildings using an adaptive capacity spectrum method”

journal of engineering structures in the year 2014.

[8] Donglin Wang and Li Wang “Nonlinear Analysis of the New Composite Frame

Structure” International Journal of Nonlinear Science in the year 2011.

[9] Ketan Patel and Sonal Thakkar “analysis of cft, rcc and steel building subjected to lateral

loading”procedia engineering in the year 2011.

[10] hou guangyu et all “design and research on composite steel and concrete frame-core wall

structure”The 14th World Conference on Earthquake Engineering October 12-17, 2008,

Beijing, China.

[11] Mahbuba Begum et all “Cost Analysis of Steel Concrete Composite Structures”Asian

Journal of Civil Engineering (BHRC) vol. 14, no. 6 (2013).

[12] M. Anbarasu and S. Sukumar “Effect Of Connectors Interaction in Behaviour and

Ultimate Strength of Intermediate Length Cold Formed Steel Open Columns” ”Asian

Journal of Civil Engineering (BHRC) vol. 14, no. 2 (2013).

CAPACITY SPECTRUM ME THOD ON RCC AND COMP OSITE …...4 Column section ISHB 450 5 Beam section ISWB...

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