This paper aims at studying the effect of earthquake loading on the constructional design of a 20-storey reinforced concrete residential building from economical point of view. This type of loading should be taken into considerations now in Iraq especially after the earthquake of 7.3 magnitude that occurred in November 2017 near the city of Halabja by about 31 kilometers. The same reinforced concrete multistory building was designed twice; once with traditional gravity dead and live loading and the second with adding earthquake loading in order to discuss the difference from structural and economical points of view. A commercial package ETABS2018 was used to analyze this 60-meter-high building. The building was analyzed according to the American code ASCE7-10, while it was designed according to ACI 318-14. A huge increase in the steel reinforcement amounts in columns, beams, slabs and shear walls were recorded due to taking the seismic load into considerations. More specifically, the reinforcing steel amounts increased by about 327%, 165%, 40% and 91.3% for columns, beams, slabs and shear walls, respectively. Therefore, cost was raised by about 328%, 165%, 40% and 91.3% for columns, beams, slabs and shear walls, respectively. It is worth to mention here that the maximum increase in main reinforcement of beams was observed on the storey 10. Whereas, in slabs, the maximum increase that was recorded in main steel reinforcement was happened from the storey 8 to the building top. In columns, the main reinforcement increase was seen on the 9th, 10th and 11th storeys. Finally, in shear walls, the main reinforcement increase was seen in the 1 st , 2 nd and 3 rd storey due to effect lateral shear forces

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International Journal of Civil Engineering and Technology (IJCIET)
Volume 9, Issue 11, November 2018, pp. 588–598, Article ID: IJCIET_09_11_057
Available online at http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=9&IType=11
ISSN Print: 0976-6308 and ISSN Online: 0976-6316
©IAEME Publication Scopus Indexed
EFFECT OF SEISMIC LOAD ON REINFORCED
CONCRETE MULTISTORY BUILDING FROM
ECONOMICAL POINT OF VIEW
Ali Kifah Kadhum
Assistant Lecturer /University of AL-Mustansiriyah/College of Engineering/
Department of Civil Engineering
Khattab Saleem Abdul-Razzaq
Professor. Dr. /University of Diyala/College of Engineering/
Department of Civil Engineering
ABSTRACT
This paper aims at studying the effect of earthquake loading on the constructional
design of a 20-storey reinforced concrete residential building from economical point
of view. This type of loading should be taken into considerations now in Iraq
especially after the earthquake of 7.3 magnitude that occurred in November 2017 near
the city of Halabja by about 31 kilometers. The same reinforced concrete multistory
building was designed twice; once with traditional gravity dead and live loading and
the second with adding earthquake loading in order to discuss the difference from
structural and economical points of view. A commercial package ETABS2018 was
used to analyze this 60-meter-high building. The building was analyzed according to
the American code ASCE7-10, while it was designed according to ACI 318-14. A huge
increase in the steel reinforcement amounts in columns, beams, slabs and shear walls
were recorded due to taking the seismic load into considerations. More specifically,
the reinforcing steel amounts increased by about 327%, 165%, 40% and 91.3% for
columns, beams, slabs and shear walls, respectively. Therefore, cost was raised by
about 328%, 165%, 40% and 91.3% for columns, beams, slabs and shear walls,
respectively. It is worth to mention here that the maximum increase in main
reinforcement of beams was observed on the storey 10. Whereas, in slabs, the
maximum increase that was recorded in main steel reinforcement was happened from
the storey 8 to the building top. In columns, the main reinforcement increase was seen
on the 9th
, 10th
and 11th
storeys. Finally, in shear walls, the main reinforcement
increase was seen in the 1
st
, 2
nd
and 3
rd
storey due to effect lateral shear forces.
Key words: Seismic analysis, Earthquake, ETABS, Response spectrum analysis,
Economical, Beam, Slab, Column, Shear wall.

2. Ali Kifah Kadhum and Khattab Saleem Abdul-Razzaq
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Cite this Article: Ali Kifah Kadhum and Khattab Saleem Abdul-Razzaq Effect of
Seismic Load on Reinforced Concrete Multistory Building from Economical Point of
View, International Journal of Civil Engineering and Technology (IJCIET) 9(11),
2018, pp. 588–598.
http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=9&IType=11
1. INTRODUCTION
Earthquakes are a real threat to people's lives and property. The recent earthquake in Halabja
city is the best proof that it is time to take seismic load seriously. Therefore, it is a must now
to predict the strength of the quake and prepare for it to avoid or minimize damage. It should
be noted here that strengthening the building against seismic load increases its cost, so this
work was done.
The earthquake leads to random ground movements, which occur in all possible directions
originating from the epicenter. Vertical motion is rare, but horizontal movement is more
common. The earthquake leads the building to vibrate and develop inertial forces in the
building itself. Because the motion of the earth is vibratory, it generates contradictory effects,
as tensile stresses can become compressive and compressive stresses can become tensile ones.
Consequently, the earthquake can lead to the compressive failure of concrete or yield of
reinforcing steel in addition to the destruction of the building's decorations. In addition, the
vibration movement leads to storey drift that hurt the inhabitants and their propertys [1].
Usually in Iraq, people do not tend to build high structures due to the foundations problems,
but the high structures in Iraq immune to earthquakes in three ways [2]: 1.Bare frame, 2.Shear
wall frame and 3.Brace frame.
Earthquake analysis is a dynamic analysis since earthquake force is dynamic in nature
whose acceleration fairly changes with time compared to the structure’s natural frequency.
Dynamic analysis gives real time results for earthquake loading in terms of dynamic
displacements, time history results and the modal analysis. The analysis is done manually for
simple structures or by using Finite element analysis for complex structures to find out the
mode shapes and frequencies [3]. In the present study, the effect of earthquake loading on
reinforced concrete beams, slabs, columns and shear walls is calculated and discussed from
constructional and economical points of view. The main parameters that were taken into
considerations in the present study in the seismic performance of model are story drift, base
shear, story deflection and time period.
2. OBJECTIVES
The main objective of the current research is to analyze and design a reinforced concrete 20
multi-storey building twice, once without taking the seismic loads into consideration, and
second, with taking seismic loads into considerations. The goal is finding and discussing the
difference between the two cases from the constructional and economical points of view.
ETABS software was used to carry out this question. The structure was subjected to traditional
gravity self-weight, finishing additional dead load, live load and seismic loads. The applied
loads on the building were calculated using ACI 318-14 Code. Seismic loads are calculated
using ASCE 7-10 and dynamic analysis of the building was conducted using response
spectrum method.
3. CASE STUDY BUILDING
The present work is carried out on the high-rise building shown in Figures 1, 2 and 3. For
analysis and design, ETABS2018 software was used depending on ACI 318-14 and ASCE 7-
10. The plan of multi-story building is 41m in length and 24m in width. The building has a

3. Effect of Seismic Load on Reinforced Concrete Multistory Building from Economical Point of
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reinforced concrete lift section that contains four shear walls. There are eight flats in the first
eight floors, and then, there are four flats in each story up to the top. Table 1 shows the three
dimensional model of the building, while Table 2 shows the applied load in detail.
Figure 1 3D model of the building
Figure 2 2D plan model case study Figure 3 Side view case study

4. Ali Kifah Kadhum and Khattab Saleem Abdul-Razzaq
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Table 1 Specification of models for 60 m height of the building
Table 2 The applied loads in detail for the two loading cases
Load Case 1st
Loading case 2nd
Loading case
Self-weight Density of the reinforced concrete is 24 kN/m3
Additional dead load Flooring load is 200 kg/m2
Live load Live load on the floors is 250 kg/m2
Earthquake load - according to ASCE 7-10 Code
4. ANALYSIS
The analysis of reinforced concrete structure has been done considering the entire structure as
a three-dimension model framed structure using ETABS [4]. Beam and columns are
considered as beam elements, while the slabs and shear walls are considered as thin plate
elements. There are 2508 joints, 1432 beams and 222 thin plate elements for slabs and shear
walls in the ETABS modeling. The main objective of modeling the whole structure as 3D
model is to take into account the behavior of each and every component in space structure
environment. The slab is modeled as a thin plate element to carry its own weight, additional
dead load and the live load as gravity distributed pressures. Lift well and staircase walls are
modeled as thin plate shear wall to resist the lateral loads like earthquake load. When seismic
loads were applied, the natural frequencies and time periods in first 10 modes are found to be
1.565, 1.46, 0.929, 0.798, 0.68, 0.401, 0.347, 0.345, 0.319, 0.24 period sec as show in Figure
4.
5. DESIGN
4-a: mode 1
period 1.565
4-b: mode 2
period 1.46
4-c: mode 3
period 0.929
4-d: mode 6
period 0.401
Figure 4 Time periods

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5.1. Design Considerations
The detailed design stage defines a complete solution for all subsystems, which are reinforced
concrete beams, slabs, columns and shear walls according to ACI 318-14. Calculating total
amounts and costs of constructional materials such as reinforcing steel bars are a
complementary step that was conducted in this study.
5.2. Seismic Analysis Procedure
The basic concepts of design theory for earthquake resistant are [6]:
i. The buildings should resist small earthquakes without causing significant damage.
ii. The buildings should resist medium earthquakes with small non-structural damage.
iii. The buildings must resist strong earthquakes with some non-structural and structural
damage.
iv. To avert damage during a strong earthquake, members must be ductile enough to dissipate
and absorb energy by post-elastic deformation.
v. In the case of the key elements failure, the structural system redundancy allows internal
forces redistribution.
vi. If the primary system or element fails or yields, the lateral force can be redistributed to a
secondary system to stop developing collapse.
5.3. Response Spectrum Method
Engineers prefer the response spectrum to deal with earthquakes for several reasons [7]:
i. Provides a real representation of earthquake in the form of a static equivalent load.
ii. Permits an obvious understanding of different vibration modes contributions to the whole
seismic response of the structure.
iii. Provides an easy way to find forces in the members that are exposed to an earthquake.‎
iv. Provides a beneficial approximate estimation of the safety and reliability of structures
subjected to earthquake.
5.4. Design Load Combinations
The design loading combinations are number of combinations of the pre-scribed response
cases for which the building is to be checked/designed, Table 3. The ETABS software
generates some default design load combinations for the design of reinforced concrete
structures [8].
Table 3 Load combinations
1 4.1DL 7 0.8DL+ EQ+X
2 1.2DL+1.6LL 8 0.8DL+ EQ+X
3 1.3DL+LL+ EQ+X 9 0.8DL+ EQ+Y
4 1.3DL+LL- EQ+X 10 0.8DL+ EQ-Y
5 1.3DL+LL+ EQ+Y 11 1.3DL+LL+ EQRS
6 1.3DL+LL+ EQ+Y 12 0.8DL+EQRS

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6. SEISMIC LOAD
ASCE 7-10 Auto Seismic Load Calculation Code was used to determine the lateral loads
caused by earthquake. These loads were calculated automatically through generating lateral
seismic loads for load pattern according to ASCE 7-10, as calculated by ETABS, assuming
that the Eccentricity Ratio is 5% for all diaphragms [9].
6.1. Structural Period
The structural period is detailed as follows [9]:
Period Calculation Method Program Calculation
Coefficient, Ct [ASCE, Table 12.8-2]
Coefficient, x [ASCE, Table 12.8-2]
Structure Height Above Base, hn
Long-Period Transition Period, TL [ASCE 11.4.5]
6.2. Factors and Coefficients
The response factor and coefficients are detailed as follows [9]:
Response Modification Factor, R [ASCE Table 12.2-1]
System Overstrength Factor, Ω0 [ASCE Table 12.2-1]
Deflection Amplification Factor, Cd [ASCE Table 12.2-1]
Importance Factor, I [ASCE Table 11.5-1]
Ss and S1 Source User Specified
Mapped MCE Spectral Response Acceleration, Ss [ASCE 11.4.1]
Mapped MCE Spectral Response Acceleration, S1 [ASCE 11.4.1]
Site Class [ASCE Table 20.3-1] D - Stiff Soil
Site Coefficient, Fa [ASCE Table 11.4-1]
Site Coefficient, Fv [ASCE Table 11.4-2]
6.3. Seismic Response
The seismic response is detailed as follows [9]:
MCE Spectral Response Acceleration, SMS [ASCE 11.4.3, Eq. 11.4-1]
MCE Spectral Response Acceleration, SM1 [ASCE 11.4.3, Eq. 11.4-2]
Design Spectral Response Acceleration, SDS [ASCE 11.4.4, Eq. 11.4-3]
Design Spectral Response Acceleration, SD1 [ASCE 11.4.4, Eq. 11.4-4]
7. RESULTS AND DISCUSSIONS
7.1. Reinforced Concrete Columns
Figures 5, 6, 7 and 8 in addition to Table 4 show the amount of increase in reinforcing steel
bars for the columns of the storeys 9, 10 and 12. The storeys 9, 10 and 11 are the most
earthquake-affected storeys by the seismic impact. They are at heights of 27-33 meters.

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0
2000
4000
6000
8000
10000
12000
C10 C43 C42 C46 C49 C54 C47 C18 C21
AreaofSteel(mm2)
Column No.
Area of Steel in the Columns of the 10th Storey
Without EQ EQ
Figure 5 The columns of the 9th
storey Figure 6 The columns of the 10th
storey
Figure 7 The columns of the 11th
storey
Table 4 Column reinforcement details
Storey Area of longitudinal steel, mm2
Area of shear reinforcement, mm2
C 50 Without Earthquake With Earthquake Without Earthquake With Earthquake
Storey 11 1250 6565 235 474
Storey 10 1250 6266 235 416
storey9 1250 4984 235 263
Figure 8 Column reinforcement details
0
1000
2000
3000
4000
5000
6000
C46 C2 C8 C50 C12
AreaofSteel(mm2)
Column No.
Area of Steel in the Columns of the 9th Storey
WITHOUT EQ EQ
0
2000
4000
6000
8000
C50 C12 C46
AreaofSteel(mm2)
Column No.
Area of Steel in the Columns of the 11th Storey
WITHOUT EQ EQ

8. Ali Kifah Kadhum and Khattab Saleem Abdul-Razzaq
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7.2. Reinforcement of the 10th
Storey Beams
Figures 8, 9 and 10 in addition to Table 5 show the top and bottom reinforcement increase
in the beams of the storey 10, the most affected storey. These beams are at 30 meters high.
Figure 9 Top reinforcement area of the beams of storey 10
Figure 11 Reinforcement beam details
Figure 10 Bottom reinforcement area of the beams of storey 10
509 509 467 509 466 509 465 509
227
509
61
134
619 619
135
509
217
60
509
134
509
11791216
1088
898
1224
1422
1223
1457
743
1454
769
257
945
890
214
1179
509
721
1178
251
1214
0
200
400
600
800
1000
1200
1400
1600
AreaofSteel(mm2)
Beam No. of Sorey 10
Bottom reinforcement area of beam in the storey 10 without EQ
EQ
799 772
576
778
581
778
584
799
376
805
168 195
595 595
197
799
376
187
805
196
771
1497
1618
1216
1885
1366
1873
1363
1735
1169
1727
1089
407
936 899
320
1497
826
1039
1492
407
1609
0
200
400
600
800
1000
1200
1400
1600
1800
2000
B5 B7 B15 B31 B73 B88 B94 B17 B104 B86 B72 B92 B108 B56 B12 B5 B24 B27 B34 B41 B35
AreaofSteel(mm2)
Beam No. of storey 10
Top reinforcement area of the beams in storey 10
WITHOUT EQ
EQ

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7.3. Reinforced Concrete Slabs
Table 6 shows the increase in reinforcing steel bars for the slabs of the 11-20 storeys, the most
affected storeys by the earthquake.
Table 6 The increase in the reinforcing steel in the slabs of the storeys 11-20
Without Earthquake With Earthquake
5@12 per 1 m (top & bottom) X, Y 7@12 per 1m (top & bottom) X, Y
7.4. Reinforced Concrete Shear Walls
Figure 12 shows the increase in reinforcing steel bars in shear walls on the storeys 1, 2 and 3,
the most affected storeys by earthquakes.
B- Without EarthquakeA- With Earthquake
Figure 12 Shear wall reinforcement area of the storeys 1, 2 & 3
7.5. Displacement
Figure 13 shows the maximum displacement values generated by the earthquake load that is
described by the response spectrum method. Based on the above, Table 7 summarizes the
differences that took place in reinforcing steel bars between the case of no earthquake and the
case of earthquake. It was found that, due to including earthquake loading, the addition in
reinforcement was by about 327%, 165%, 40% and 91.3% for columns, beams, slabs and
shear walls, respectively. Therefore, cost was raised by about 328%, 165%, 40% and 91.3%
for columns, beams, slabs and shear walls, respectively. In other words, the total cost
increased by about 624.3% due to taking earthquake into considerations.
Table 5 Beam reinforcement details
Beam No. Area of longitudinal Steel, mm2
Area of shear reinforcement, mm2
Story 11
Without
Earthquake
With Earthquake
Without
Earthquake
With Earthquake
B 30 562 1106 171 1218
B 44 903 1252 324 1520
B 94 908 1401 353 1639

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Figure 13 Maximum Story Displacement
Table 7 Difference Summery
Member
type
No Earthquake With Earthquake Comparisons
Number
of elements
Reinforcing
Steel
Amount
(ton)
Cost
(unit)
Numbers
of elements
Reinforcing
Steel
Amount
(ton)
Cost*
(unit)
%
Increase
in
steel reinf.
%
Increase
in
total cost
Columns 992 33 24.7 992 141 105.7 327 328
Beams 1432 54 40.5 1432 143 107.3 165 165
Slabs 20 183 124.4 20 256 174 40 40
Shear wall 520 23 15.6 520 44 29.9 91.3 91.3
Total increase in cost 624.3
*Cost =235,750 U.S. Dollars
8. CONCLUSIONS
The earthquake applied affective lateral forces on the building side. This effect was obvious in
the columns, beams and shear walls, especially in the joints among them. These joints have
been strengthened by additional reinforcement to withstand the lateral forces of the
earthquake. The slabs were surrounded monolithically by the beams, so the impact of the
earthquake was obvious, but less than that took place in columns, beams and shear walls. The
addition in reinforcement was by about 327%, 165%, 40% and 91.3% for columns, beams,
slabs and shear walls, respectively. Therefore, cost was raised by about 327%, 165%, 40%
and 91.3% for columns, beams, slabs and shear walls, respectively. More specifically, the
total cost of the building increased by 624.3% due to taking the earthquake into
considerations.
REFERENCES
[1] S. S. Dash, "Seismic Analysis of High- Rise Building by Response Spectrum Method”,"
india, 11 May 2015.
[2] S. G. C. K. C. G. S.S. Patil, "Seismic Analysis of High-Rise Building by Response
Spectrum Method," International Journal Of Computational Engineering Research, p. 272,
March-2013.
[3] V. K. Y. M. S. C. Ajay H A, "Seismic Analysis of a Multistorey RC Building for Various
Lateral Load Resisting Systems by Response Spectrum Method," International Journal for

11. Effect of Seismic Load on Reinforced Concrete Multistory Building from Economical Point of
View Copper Ions from Simulated Aqueous Solution
http://www.iaeme.com/IJCIET/index.asp 598 editor@iaeme.com
Research in Applied Science & Engineering Technology (IJRASET), vol. 4, no. VII, p.
657, July 2016.
[4] ETABS 2016 V16.2.1 Integrated Building Design software manual by Computers and
Structures Inc..
[5] V. Navya Medasana, "Seismic study and performance of 30 storey high rise building with
beam slab, flat slab and alternate flat-beam slab systems in Zone-V," International
Research Journal of Engineering and Technology(IRJET), vol. 04, no. 02, p. 1184, Feb -
2017.
[6] S. R. H. Shobeni1, "Seismic Analysis and Design of G+18 Floors Multistoried Building
using ETABS 2013," International Journal of Scientific Research in Science and
Technology (www.ijsrst.com), vol. 3, no. 7, October-2017.
[7] R. S. D. Narasimhulu2, "Seismic Analysis of Medium Rise Open Ground Storey Framed
Building by Response Spectrum Analysis Method," IJSRD - International Journal for
Scientific Research & Development, vol. 5, no. 10, 2017.
[8] A. B. S. D. S. V. Divya Sree*1, "Seismic Analysis and Design of Shear Walls in Response
Spectrum Method By Using Etabs," International Journal of Scientific Research in
Science and Technology (www.ijsrst.com), vol. 3, no. 4, p. 189, 18 May 2017.
[9] ASCE 7-10 American Society of Civil Engineers – Minimum Design Loads for Buildings
and other structures (Table 12.2-1) [ASCE 11.4.5] [ASCE Table 12.2-1] [ASCE Table
11.5-1] [ASCE 11.4.1] [ASCE Table 11.4-2] [ASCE Table 20.3-1] [ASCE 11.4.3, Eq.
11.4-1].
[10] ACI 318M-14 Building Code Requirements for Structural Concrete and Commentary.
[11] P. N. G. G. Pardeshi sameer1, "Study of seismic analysis and design of multi storey
symmetrical and asymmetrical building," International Research Journal of Engineering
and Technology (IRJET), vol. 03, no. 015, Jan-2016.
[12] P. R. G. Prof. N. N. Shinde1, "Seismic Comparison of Commercial Building between
Equivalent Static Analysis and Response Spectrum Analysis," International Journal of
Scientific Research in Science, Engineering and Technology (ijsrset.com), vol. 2, no. 3,
June 2016.
[13] D. G. V. S. Shamshad Begum, "Seisimic Analysis of a High Rise Unsymmetrical Building
with Dampers Using ETABS," International Journal of Scientific Research in Science and
Technology (www.ijsrst.com), vol. 2, no. 3, June 2016.