2018 Scienceline Publication  
Journal of Civil Engineering and Urbanism  
Volume 8, Issue 1: 01-05; Jan 25, 2018  
ISSN-2252-0430  
Studies on Regular and Irregular Tall Structures  
Subjected to Earthquake Loading  
Miss Chaya1 and Naveen GM2  
  
1Assistant Professor, Department of Civil Engineering, EIT, Chamarajanagar-571313, Karnataka 571313, India  
2Assistant Professor, Department of Civil Engineering, Government .Engineering College, Chamarajanagara-571313, Karnataka  
571313, India  
Corresponding author’s E-mail: naveengm.gowda@gmail.com  
ABSTRACT: Multi storey buildings are constructed by Reinforced concrete are subjected to earthquake  
forces are affected dangerously, they get failure during earthquake. The main reason for this failure is  
that the irregularity in building structures. In this paper study is made to find the response of regular and  
irregular building structures having plan irregularity located in seismic zone V. In this present study  
Analysis has been made by taking 10 storey building by Response Spectrum Method using ETABS  
2015 and code IS 1893:2002 (part 1). Analysis is carried out for Regular and Irregular buildings at a  
height of 35.5 m in zone V. Behavior of structures are comparing the responses in the form of maximum  
storey displacement, storey drift, storey stiffness, periods and frequencies of modes during earthquake.  
Presently there are four models. One is Regular structure and remaining are Irregular structural models,  
all models have different shape but having same area. An attempt is made to study the Response of  
building structures with respect to the loads and their combinations. The results comparison is made by  
taking maximum load combinations considering the primary loads (LL, DL, WL, and EQL). Totally  
four Configuration models are considered for the analysis.  
Keywords: Horizontal irregularity, Earthquake load, Storey shear, Maximum storey displacement,  
Maximum storey drift.  
INTRODUCTION  
the ground motions are occurred, the structures are  
affected in three dimensions in the three directions, one is  
vertical direction (Z) and other two are horizontal  
directions (X, Y) .The structure is mostly affected by the  
horizontal direction of vibrations. All the structures are  
designed to satisfy the gravity loads acted in vertical  
direction. In the design specifications safety factors are to  
be considered, because of this most of the structure are  
tended to be adequately protected against vertical shaking.  
But its affects should be considered in design of the  
reinforced concrete (R.C.C) structures. When we are  
considering design of building by considering vertical  
ground motions is not safe. It is to be considering the  
horizontal displacement of the building. Generally, forces  
acted in the horizontal ground motions of the earthquake  
are taken important for the design of the structures.  
Therefore the building structures must be designed to  
resist the horizontal forces acted due to the earthquake.  
Structure is subjected to seismic forces during earthquake,  
structures undergo displacements at the base and the  
components of the structure are also get displaced and  
damaged during the earthquake (Agarwal and Shrikande,  
2011; Duggal, 2007). During earthquake seismic forces  
are developed, Structure is experienced there seismic  
forces. Seismic forces developed the seismic waves and a  
wave reaches the structure during earthquake. The waves  
generated from the earthquake epicenter disturb the  
structure during earthquake. They can produce ground  
motions in the structure. Earthquake is the natural  
phenomenon; it is the Rapid movement of the earth  
surface taking place at or below the surface of the earth.  
When the earthquake takes place the layers of the soil in  
the earth also displace the structure components of the  
building are get vibrated by this ground motions. When  
To cite this paper: Chaya M and Naveen GM (2018). Studies on Regular and Irregular Tall Structures Subjected to Earthquake Loading. J. Civil Eng. Urban., 8 (1): 01-05.  
www.ojceu.ir  
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Table 1. Parameters considered for the building design  
Objectives of the study  
• This study focus is on the behavior of structures  
during earthquake having irregularities in plan and having  
same area.  
Parameter  
Type\Value  
Structure Type  
Number of Stories  
RCC Building Structure  
10  
• To study the parameters of storey shear, storey  
displacements, maximum storey drift of all models during  
earthquake.  
• To study the frequencies and periods in different  
modes.  
Bottom Storey Height(Basement)  
4m  
Storey’s Height(Ground+ Floors)  
3.5m  
Regular , Irregular Building  
Type of Structure  
Structure  
1600 m2  
5m  
0.2mX0.45m  
M20  
Area of Structure  
Bay Width in both direction  
Beam Size  
Grade of Concrete  
Column Size  
Grade of Concrete  
Thickness of Slab  
0.3mX0.9m  
M25  
0.12m  
MATERIALS AND METHODS  
Concrete Brick Thickness  
0.2m  
4 KN\m2  
Model of the structures  
Live Load  
Parameters consider. In the present study four  
different buildings are considered, one is horizontal  
regular and other three are irregular buildings. Buildings  
are modelled using ETABS package and analysed  
(Prashanth et al., 2012). The properties of the considered  
building configurations in the present study are  
summarized below.  
Seismic Zone  
V ( Z=0.36 )  
1.5  
5
Importance Factor  
Response Reduction Factor  
Soil Type  
II  
Analysis of the structures  
Following models are analyzed as special moment  
resisting frame using response spectrum analysis.  
Figure 1. Plan and 3d view of model 1  
Figure 2. Plan and 3d view of model 2  
To cite this paper: Chaya M and Naveen GM (2018). Studies on Regular and Irregular Tall Structures Subjected to Earthquake Loading. J. Civil Eng. Urban., 8 (1): 01-05.  
www.ojceu.ir  
2
Figure 3. Plan and 3d view of model 3  
Figure 4. Plan and 3d view of model 4  
model 4 (Irregular building) and the ending frequency is  
greater in model 3.  
The figure 7 shows the variation in the storey drift. It  
is less in storey 1 and increases up to storey 3, after 3  
storeys it is decreases up to last storey.  
Load combinations  
Analysis is done for all the loads of 20 combinations  
by using ETABS, out of which the critical load  
combination is, (1.2DL+1.2LL+1.2EQY)  
In this figure  
displacement is increases with increases in the number of  
storey. From the table model 2, 3, 4 (irregular buildings)  
8 it is observed that storey  
RESULTS AND DISCUSION  
The results are presented by plotting the graph for  
each models considered in the study. The analysis carried  
out by the Response spectrum analysis. The result of  
periods and frequencies, maximum storey drift, storey  
maximum displacements, storey shear is presented for all  
models. In this study regular building is compared with  
irregular building; the performance of the models is  
observed in high seismic zone V.  
Figure 5 shows the variation of models for different  
periods in different number of modes. It is observed that  
the periods of vibrations are decreases with increases in  
number of modes. Model 1 has greater period of vibration  
as compared to other models.  
have similar displacement. Model  
displacements.  
In figure 9 storey shear increases with decrease in  
number of stories. Storey shear is maximum in Irregular  
building structure. Model 3 has greater storey shear. Shear  
force is greatly affected the base.  
1
has greater  
Periods of modes of vibration  
Frequencies of all models  
Maximum storey drift of all models of (1.2DL +  
1.2LL + 1.2EQY)  
Storey displacement in (1.2DL + 1.2LL + 1.2EQY)  
Storey shear in kn of all models in (1.2DL + 1.2LL +  
1.2EQY)  
From the figure 6 it is observed that frequency is  
increases with increases in modes number. In the  
beginning of the vibrations the frequency is more in  
Storey shear in kn of all models in  
(1.2DL+1.2LL+1.2EQY)  
To cite this paper: Chaya M and Naveen GM (2018). Studies on Regular and Irregular Tall Structures Subjected to Earthquake Loading. J. Civil Eng. Urban., 8 (1): 01-05.  
www.ojceu.ir  
3
Table 2. Periods of modes of vibration in seconds  
Table 4. Maximum storey drift of all models of  
(1.2dl+1.2ll+1.2eqy)  
Mode no  
Model 1  
2.794  
2.212  
2.139  
0.914  
0.686  
0.643  
0.53  
Model 2  
2.767  
2.251  
2.133  
0.905  
0.695  
0.64  
Model 3  
2.763  
2.098  
2.056  
0.902  
0.639  
0.617  
0.52  
Model 4  
2.751  
2.277  
2.11  
Storey  
Model 1  
0.000935  
0.00176  
Model 2  
0.000932  
0.001749  
0.002487  
0.003068  
0.0035  
Model 3  
0.000976  
0.001781  
0.002516  
0.003096  
0.003526  
0.003826  
0.004016  
0.004101  
0.004012  
0.002844  
Model 4  
0.000938  
0.001747  
0.002481  
0.003058  
0.003488  
0.003788  
0.00398  
1
10  
9
2
3
8
0.002506  
0.003093  
0.003529  
0.003835  
0.004031  
0.004128  
0.004066  
0.002968  
4
0.899  
0.699  
0.632  
0.52  
7
5
6
6
5
0.003803  
0.003997  
0.004091  
0.004024  
0.002925  
7
0.524  
0.368  
0.359  
0.327  
0.267  
0.229  
4
8
0.366  
0.363  
0.329  
0.27  
0.354  
0.332  
0.315  
0.262  
0.205  
0.367  
0.356  
0.322  
0.264  
0.227  
3
0.004072  
0.004001  
0.002888  
9
2
10  
11  
12  
1
0.23  
Figure 7. Maximum storey drift  
Figure 5. Variation of periods  
Table 3. Frequencies of models in cycles per seconds  
Table 5. Storey displacement in mm (1.2dl+1.2ll+1.2eqy)  
Mode No  
Model 1  
0.358  
0.452  
0.468  
1.094  
1.458  
1.555  
1.888  
2.73  
Model 2  
0.361  
0.444  
0.469  
1.105  
1.44  
Model 3  
0.362  
0.477  
0.486  
1.109  
1.565  
1.622  
1.925  
2.822  
3.008  
3.18  
Model 4  
0.364  
0.439  
0.474  
1.112  
1.432  
1.582  
1.923  
2.725  
2.812  
3.105  
3.787  
4.401  
Storey  
Model 1  
109.5  
106.2  
100  
Model 2  
108.5  
105.2  
99.1  
90.4  
79.7  
67.4  
54.1  
40.1  
25.8  
11.7  
0
Model 3  
108.9  
105.4  
99.2  
90.4  
79.6  
67.2  
53.8  
39.8  
25.4  
11.4  
0
Model 4  
108  
1
10  
9
8
7
6
5
4
3
2
1
0
2
104.7  
98.6  
89.9  
79.2  
67  
3
4
91.3  
80.4  
68.1  
54.7  
40.5  
26.1  
11.9  
0
5
6
1.562  
1.909  
2.716  
2.788  
3.063  
3.751  
4.359  
7
53.7  
39.8  
25.6  
11.6  
0
8
9
2.755  
3.039  
3.704  
4.354  
10  
11  
12  
3.813  
4.88  
Figure 8. Variation of displacement of stories  
Figure 6: Frequencies of vibrations  
To cite this paper: Chaya M and Naveen GM (2018). Studies on Regular and Irregular Tall Structures Subjected to Earthquake Loading. J. Civil Eng. Urban., 8 (1): 01-05.  
www.ojceu.ir  
4
Table 6. Storey shear of all models in kN  
REFERENCES  
(1.2dl+1.2ll+1.2eqy)  
Konakalla R, Dutt chilakapati R, Babu Raparla H (2014).  
Effect of vertical irregularity in multi-storied  
buildings under dynamic loads using linear static  
Analysis. International Journal of Education and  
Applied Research (IJEAR). Vol. 4, Issue SPL-2.  
Naveen GM and Suresh GS (2012). Behaviour of Light  
weight Ferrocement Beam under Monotonic Flexural  
loading. Journal of Structural Engineering (JOSE),  
Vol. 39, No.4.  
Bagheri B, Salimi Firoozabad E and Yahyaei M (2012).  
Comparative Study of the static and Dynamic  
Analysis of Multistorey Irregular Building.  
International Journal of Civil, Environmental,  
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Model 2  
Model 3  
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Agarwal P and Shrikande M (2011). Earthquake Resistant  
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Figure 9. Storey shear along number of stories  
CONCLUSION  
1. In general it is observed that period of modes of  
vibrations decreases with increase in number of mode.  
Model 1 has greater period of vibration.  
2. Frequencies of modes increase with increasing in  
number of modes. Model 3 has greater frequency.  
3. Maximum storey drift is less in bottom storey,  
after bottom storey that it increases with increase in up to  
storey 7 again it is decreases.  
4. Storey displacement increases with increases in  
storey height. Displacement is greater in regular building.  
5. Storey shear increases with decreases in number  
of storey and shear is maximum at the base of the  
building. Storey shear is maximum in model 3.  
6. Considering the above conclusion results we  
conclude that plan asymmetry like horizontal irregularity  
has slight differences in results of all parameters.  
BIOGRAPHIES  
Dr. Naveen G M, is working as Assistant  
Professor in Government Engineering College  
Chamarajanagara, Karanataka, India-571313, received his  
BE degree from UBDT college Davangere; M.Tech in  
MCE, Hassan and PhD at National Institute of  
Engineering, Mysore under VTU. Research interests  
include the Reinforced Concrete Structure and steel  
structure Analysis and design in civil structures.  
Author’s contribution  
All authors contributed equally to this work.  
Miss. Chaya S, assistant professor of civil  
Competing interests  
The Authors declare that they have no competing  
interests  
engineering Department, EIT Chamarajanagar, have an  
experience in teaching and research in structural  
Engineering field. Research interests include the  
Reinforced Concrete Structure design in civil structures.  
To cite this paper: Chaya M and Naveen GM (2018). Studies on Regular and Irregular Tall Structures Subjected to Earthquake Loading. J. Civil Eng. Urban., 8 (1): 01-05.  
www.ojceu.ir  
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