International Journal of Trend in Scientific Research and Development (IJTSRD)

Volume 4 Issue 5, July-August 2020 Available Online: www.ijtsrd.com e-ISSN: 2456 – 6470

Seismic Analysis of Framed R.C. Structure with

Base Isolation Technique using E-Tabs
Rohan G Raikar1, Dr. Shivakumaraswamy2, Dr. S Vijaya3, M. K Darshan4
1M.Tech Scholar, 2Professor, 3Professor & Head, 4Assistant Professor,
1,2,3,4Dr. Ambedkar Institute of Technology, Bengaluru, Karnataka, India

ABSTRACT How to cite this paper: Rohan G Raikar |

A Natural Calamity like an earthquake has taken a million lives throughout Dr. Shivakumaraswamy | Dr. S Vijaya |
in our past. The force induced due to earthquake is dangerous and last for M. K Darshan "Seismic Analysis of
short duration of time. There are various techniques that can be used resist Framed R.C. Structure with Base
the force of an earthquake such as base isolation, bracing etc. The principle Isolation Technique using E-Tabs"
of base isolation is to isolate the structure from the motion of an Published in
earthquake and protect the structure and also reduce the force being International
transmitted to the building due to earthquake. For this study,(G+13) Journal of Trend in
storied R.C. frame building is considered and time history analysis is Scientific Research
carried out using E-Tabs 2017 software, and also study investigates and Development
structural behavior of multi-story building with or without base isolation (ijtsrd), ISSN: 2456-
subjected earthquake ground motion. The Lead Rubber Bearing (LRB) is 6470, Volume-4 | IJTSRD33166
designed as per UBC-97 code and the same was used for the analysis of Issue-5, August
base isolation system. Here we shall studying earthquake resistivity of 2020, pp.1477-1483, URL:
structure by analyzing the base isolation structure to compare its structural www.ijtsrd.com/papers/ijtsrd33166.pdf
performance with fixed base isolation.
Copyright © 2020 by author(s) and
KEYWORDS: Base Isolation, Lead rubber bearing, Time history analysis International Journal of Trend in
Scientific Research and Development
Journal. This is an Open Access article
distributed under
the terms of the
Creative Commons
Attribution License (CC BY 4.0)
(http://creativecommons.org/licenses/
by/4.0)
1. INTRODUCTION
Conventional Seismic design attempts to make building
that do not collapse under strong earthquake shaking,
but may sustain damage to non-structural elements and
to some structural members in the building. The Idea
behind base isolation is to detach (isolate) the building
from the ground in such a way the earthquake motions
are not transmitted up through the building, or at least
greatly reduced.

There are different types of Isolation Components.

A. Elastomeric Isolators Fig-1: Lead Rubber Bearing
 Natural Rubber Bearing
 Synthetic Rubber Bearing Lead Rubber Bearing consists of alternate layers of
 Lead Rubber Bearing rubber and steel plates with one or more lead plugs that
are inserted into the holes. The lead core deforms in
B. Friction Pendulum Bearing shear providing the bilinear response and also provides
Based on Sliding Surface Geometry, there are two types the initial rigidity against minor earthquake and strong
of sliding bearings, namely: wind. The Steel plates in the elastomeric bearing gives
I. Flat Slider Bearings large plastic deformations, So, an elastomeric bearing
II. Curved Slider Bearings was then replaced by Lead plug and was tested. Lead
rubber bearing represents an economical solution for
We Consider Lead Rubber Bearing Isolator for analysis, the seismic isolation problems because it combines the
let us know some keywords on LRB functions of vertical support, of rigidity of service load
levels, and of horizontal flexibility at earthquake load.

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2. LITERATURE REVIEW The building provided by circular shape high damping
Many methods have been proposed for achieving the rubber bearing as per required diameter in accordance
optimum performance of structures subjected to with Euro Code 8 to act as a base isolation system. The
earthquake excitation. The use of Lead rubber bearing main objective of this study is to improve the
isolators for absorbing energy is the best technique. earthquake resistant design approach by studying the
Many papers have been published related with base properties like horizontal flexibility to increase
isolation technique as an earthquake resistant device. structural period and reduce the transfer of seismic
Some of them are discussed below. energy to super structure.

Radmila B. Salic et all In this paper the authors have Juan C. Ramallo, et al In this paper authors have
demonstrated the effect of dynamic response of the investigated the effects of using controllable semi active
seven-story residential building under the earthquake dampers, such as magneto rheological fluid dampers, in
ground motion. The fixed base model represents the a base isolation system. A two degree of freedom model
dynamic behavior of the structure and seismic isolated of a base isolated building is used. The fundamental
model representing the dynamic behavior of the concept is to isolate a structure from ground, especially
structure isolated by lead rubber bearing seismic in the frequency range where the building is most
isolation system. Dynamic analyses of both the model affected. The goal is to reduction in interstory drifts and
have been performed by E-tabs. Dynamic responses of floor accelerations to limit damage to the structure and
fixed base and seismic isolated model have been its contents in a cost effective manner.
calculated for four types of real earthquake time
histories of different frequency characteristics whose J. C. Ramallo, et al have presented an innovative base
value is determined based on detailed site response isolation strategy and shows how it can effectively
analysis. The authors have showed that increase of protect the structures against extreme earthquakes
natural period of structure increases flexibility of the without sacrificing performance during the more
same structure. In seismic isolated model, base shear frequent, moderate seismic events. This innovative
force is highly reduced. Increased flexibility of the concept includes base isolation system with semi active
system led to increase of the total displacements due to or controllable passive dampers for the seismic
the elasticity of existing isolation. response mitigation.

V. Kilaret al In this paper four storey RCC building is Pradeep Kumar T. V. et al has shown force
designed according to Euro Code 8 for seismic analysis deformation behavior of isolation bearings. In this paper
and dynamic performance evaluation. Different sets of the isolation bearing consists of isolators which increase
base isolation devices are studied for investigation. First the natural period of the structure away from high
case is the use of simple rubber bearing and second one energy periods of the earthquake and a damper to
is the use of lead rubber bearing as a base isolation absorb energy in order to reduce seismic force.
system. For the investigation of each system a soft,
normal and hard rubber stiffness with different 3. METHODOLOGY
damping values were used. Non-linear pushover By introducing the flexible layer between the foundation
analysis was performed with the recent version of and the superstructure, the upper structure will act as a
computer analysis software Sap2000. From this study it rigid body and the behaviors can be predicted by linear
is concluded that the stiffer isolators with higher theory for 2-degree of freedom system. In order to
damping gives smaller target base displacements as obtain the behavior of isolation system, linear spring
compared to softer one with lower damping. and linear viscous damping will be implemented to this
simple 2-DOF system, linear spring and linear viscous
A. B. M. Saiful Islam et al In this paper a soft storey damping will be implemented to this simple 2-DOF
building is analyzed for seismic loading by creating a system model. The model shown in Figure 3.1
building model having lot of open spaces. The soft represents a rigid body sitting on a layer of flexible
stories creates the major weak point in earthquake bearings.
which means that during the event when soft storey
collapses, it can make the whole building down. The
research includes the placement of two types of
isolators, first is lead rubber bearing (LRB) and second
one is high damping lead rubber bearing (HDRB). Each
storey is provided by isolators and its consequences
were studied for different damping values. Finally, it has
concluded that the flexibility, damping and resistance to
service loads are the main parameters which affects for
practical isolation system to be incorporated in building
structures. Fig 2: Parameters of 2-DOF Isolation Model

Di Sarno, et al has presented the structural analysis of Where,

the complex irregular multi storey RC frame used for the M, US = The mass and the shear displacement of the
hospital building. It was carried out by means of modal superstructure, respectively
analysis with response spectrum. The structure exhibits Mb, Ub = The mass and the shear displacement of the
large mass eccentricity due to its irregularity in shape. base floor above the isolation layer

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Ks, Cs = Structure stiffness and structure damping, proposed building by providing the reference points and
respectively drawing the lines. Other method of modeling includes
Kb, Cb = Stiffness and damping of the isolation. drawing center line diagram in AutoCAD save the file
Ug = Ground Displacement. in.dxf Format. Modeling involves defining material
properties, frame sections, for a said structure.
The governing equation of motions is
𝑚𝑢̈ 𝑆 + 𝑐𝑢̇ 𝑠 + 𝑘𝑢𝑠 = −𝑚(𝑢𝑔 +̈ 𝑢𝑏̈ ) Table 1: Model Details
SI NO Particulars Description
For the fixed-based building, we can obtain the frequency 1 Type of Frame SMRF
and the fundamental period by following formulas: 2 No of Storey’s G+13
𝐾 2𝜋 𝐶 3 Height of Storey’s 3
𝑊𝑓 = √𝑚 𝑇𝑓 = 𝜉
𝑊𝑓 𝑓
= 2𝑚𝑤𝑓 4 Height of Building 41.5m
5 Slab Thickness 200mm
Where, Wf, Tf are the natural frequency and period, 6 Size of Column (750 X 750)mm
respectively, ξ represents the damping ratio. By including 7 Size of Beam (230 X 450)mm
the stiffness and the damping of an isolation layer into a 8 Wall Thickness 230mm
fixed-based building, we will obtain a new frequency and 9 Concrete Grade M30
period of the isolated structures as follows. 10 Steel Grade Fe 415
𝑏
𝑊𝑏 = √𝑚+𝑚
𝑘
𝑇𝑏 =
2𝜋
𝜉 =
𝐶𝑏 11 Specific Weight of RCC 25kN/m3
𝑏 𝑊𝑏 𝑓 2(𝑚+𝑚𝑏 )𝑤𝑏 12 Specific Weight of Infill 20kN/m3
13 Type of Soil Hard Soil
As a result of the much lower value of stiffness, we will 14 Response Spectra UBC 97
obtain the new much longer period Tb with respect to Response Reduction
fundamental period Tf of the building. The long period of 15 5.5
Factor(R)
vibration is the effective factor that reduces the force 16 Importance Factor(I) 1
impacts to the structure. Linear theory equations and their
derivations are detailed in “Design of Seismic Isolated
Structures” by J.M. Kelly and “Introduction to Structural
Motion Control” by J.J. Connor. The mode shapes of the
building under linear theory can be determined as follows.

Fig 3: Mode Shape

In the calculation, by introducing the flexible layer to the

foundation, it is clear that the response of the second
mode is negligible in comparison with the first mode. The
first mode reflects the dynamic response of the isolated
floor while the structure above tends to act rigidly. The
higher modes, which produce the floor interstory drift and
accelerations, have very small participation factors. As a
result, the high energy in the ground motion at higher
Fig 4: 3D Model of (G+13) building
frequencies cannot be transmitted to the structure. Given
the fact that an isolation system redirects earthquake
5. DESIGN OF LEAD RUBBER BEARING ISOLATOR
energy rather than absorb it, an isolation system doesn't
 MANUAL DESIGN OF LRB ISOLATORS
depend on damping, although additional damping can be a
The calculation of lead rubber bearing is carried out as
supplemental tool to mitigate earthquake excitations.
follows:
1. The first step is to decide the minimum rubber
Based on the fact that damping is not main factor in
bearing diameter depending on vertical reaction. This
isolation efficiency, we did not include the effect of
maximum vertical reaction obtained from analysis
damping in previous analysis. Supplementing isolation
result of fixed base building which is found to be
with damping can provide a means of energy dissipation,
6274.4738kN is considered as supporting weight
and this is a second factor in reducing structural
LRBs.
responses.
2. Second step is to set the target period (2.5 seconds
appears to be the desired one) and the effective
4. MODELLING IN ETABS
damping β is assumed to be 5% for reinforced
First select the proper units and arrange the grid system
concrete structure according to IS 1893:200211
as per the plan. Draw the center line diagram of the
§7.8.2.1.

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3. In third step, the spectral acceleration from the Where,
response spectrum graph in relation with the desired 𝜎𝑝𝑏 = Total yield stress in lead, It is assumed to be 11Mpa.
period is found to be 0.544. Area of lead core in LRB
4. In next step design displacement is calculated: 𝜋 𝜋
Apb = 𝑥 (𝐷𝑝𝑏 )2 = 𝑥 (0.176)2 = 0.024m2
𝑇𝑒𝑓𝑓 4 4
𝑑𝑏𝑑 = ( 2𝜋 )𝑆𝑎 Dff =Diameter of force free section
2.5
𝑑𝑏𝑑 = ( ) 𝑥 0.544 = D bearing – 2t
2𝜋 = 2.35 – 2(0.144)
𝑑𝑏𝑑 = 0.216𝑚 = 2.062m
Where, Aff = Force Free Area
Sa = 0.544,Spectral Acceleration 𝜋 𝜋
= 4 (𝐷𝑓𝑓 )2 = 4 (2.062)2 = 3.34m2
Teff = 2.5sec, Target Period
𝑑𝑏𝑑 = Design displacement of isolator.
AL = Total loaded Area
5. The required stiffness to provide a period is the = Force Free Area – Area of lead core
effective stiffness: = 3.34 – 0.024
2𝜋 𝑊 = 3.316m2
𝐾𝑒𝑓𝑓 = (𝑇 )2 𝑔𝑖
𝑒𝑓𝑓
2𝜋
𝐾𝑒𝑓𝑓 = (2.5)2 9.81
76676.7014 13. Circumference of force free section
Cf = π x t x Dff = π x 0.144 x 2.062 = 0.933m
𝐾𝑒𝑓𝑓 = 49371.25 𝑘𝑁/𝑚
𝐿𝑜𝑎𝑑𝑒𝑑 𝐴𝑟𝑒𝑎
14. Shape Factor = Si =
Where, 𝐶𝑖𝑟𝑐𝑢𝑚𝑓𝑒𝑟𝑎𝑛𝑐𝑒 𝑜𝑓 𝑓𝑜𝑟𝑐𝑒 𝑓𝑟𝑒𝑒 𝑠𝑒𝑐𝑡𝑖𝑜𝑛
𝐴𝐿 3.316
Teff = Effective fundamental period of the Si = 𝐶 = 0.933 = 3.55 = 4
𝑓
superstructure corresponding to horizontal
translation, the superstructure assumed as a rigid 14. H = Total Height of LRB
body. H = (N x t) + (N – 1)ts + 2tap
Wi = The weight on the isolator i.e. maximum vertical 0.2 0.2
N = 𝑡 = 0.01 = 20
reaction.
𝐾𝑒𝑓𝑓 = Effective stiffness of the isolation system in the H = (20 x 0.01) + (20 – 1) x0.003 + 2 x 0.04
principal horizontal direction under consideration, = 0.337m
at a displacement equal to the design displacement
dbd. Where,
N = Number of Rubber layer.
6. ED = Dissipated energy per cycle at the design t = Single rubber layer thickness = 0.01m
displacement (dbd) ts = Thickness of steel lamination = 0.003m
ED = 2Keffdbd2β tap = Laminated anchor plate thickness = 0.04m
ED = 2 x 49371.25 x 0.2162 x 0.05
15. Bearing horizontal stiffness (Kb)
ED = 230.35kN.m 𝐺𝐴 700 𝑥 0.138
Kb = 𝐻 𝑟 = 0.337 = 286.65kN/m
7. Fo = Force at zero displacement under cyclic loading.
𝐸 230.35
Fo = 4𝑑𝐷 = 4 𝑥 0.216 = 266.61 kN Where,
𝑏𝑑 G = Shear modulus (Varying from 0.4 to 1.1Mpa)
Ar = Rubber layer area = 0.138m2
8. Kpb = Stiffness of lead core of lead – rubber bearing H = Height of LRB = 0.337m
𝐹 266.61
𝐾𝑝𝑏 = 𝑑 𝑜 = 0.216 = 1234.31𝑘𝑁/𝑚
𝑏𝑑
16. Total bearing vertical stiffness (Kv)
𝐺𝑆 2 𝐴 𝐾6
9. Kr = Stiffness of rubber in LRB Kv = (6𝐺𝑆𝑖 2+𝑘)𝐻
𝑟
𝑖
Kr = Keff – Kpb = 49371.25 – 1234.31 = 48136.94kN/m 700 𝑥 42 𝑥 0.138 𝑥 2000 𝑥 103 𝑥 6
Kv = (6 𝑥 700 𝑥 52 +2000 𝑥 103 )0.337
10. tr = Total thickness of LRB Kv = 26.6 MN/m
𝑑 0.216
𝑡𝑟 = 𝛾𝑏𝑑 = 1.5 = 0.144𝑚
Where,
Si = Shape Factor = 5
11. D bearing = Diameter of lead rubber bearing K = Rubber Compression modulus = 2000Mpa.
𝐾𝑟𝑡𝑟 48136.94 𝑥 0.144
D bearing = √ =√ = 2.35m
400𝜋 400 𝑥 𝜋 From above calculation summary of lead rubber bearing
Where. design for symmetric building is as shown in Table 1
D bearing = Diameter of lead rubber bearing.
tr= Total lead rubber bearing thickness. Table 2: Summary of LRB parameters
1. Required Stiffness (keff) 49371.25 kN/m
12. Total loaded area (AL) calculation 2. Bearing horizontal stiffness (kb) 286.65 kN/m
Dpb = Diameter of lead core of LRB 3. Vertical Stiffness (Kv) 26.6 MN/m
4𝑓
𝐷𝑝𝑏 = √ 𝑜 = √
4 𝑥 266.61
= 0.176m 4. Yield Force (F) 266.61 kN
𝜋𝜎 𝜋 𝑥 11000
𝑝𝑏 5. Stiffness Ratio 0.1
6. Damping 0.05

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 BASE ISOLATION CALCULATION IN ETABS 27. So, Area of lead Plug Required. A = 0.006365 m2
Design the LRB isolator according to UBC-97 using the
APB = QR / 10x103
Maximum Vertical Load
1. Maximum Vertical Load Column Support, 28. So, Diameter of Lead Plug Required, d = 0.090045m
W=6274.4738 kN = 90.045mm
2. Shear Modulus, G =0.7 N/mm2 (Mpa) 29. Recalculation of Rubber Stiffness Keff toKeff(R) =
3. Design Time Period, TD =2.5 sec 3716.1158 kN/m
4. Seismic Zone Factor, Z =0.2 (UBC-97 ,Vol-2, Table 16-I Keff(R) = Keff – QR/DD
& Zone Map) 30. Maximum Shear Strain of Rubber, γ =100%
5. Seismic Source Type =B 31. Total Thickness of Rubber, tr= 0.198994 m
6. Near Source Factor, Na =1 (UBC-97,Vol-2,Table 16-S) tr= DD / γ
7. Near Source Factor, NV =1 (UBC-97,Vol-2,Table 16-T) 32. Area of Bearing, ALRB = 1.0564 m2
8. ZNV = 0.2 𝐾𝑒𝑓𝑓(𝑅) ∗𝑡𝑟
ALRB = 𝐺
9. Maximum Capable earthquake response coefficient,
Mm =1.5 (UBC-97,Vol-2,Table A-16-D) 33. Diameter of Bearing, DLRB = 1.1600605 m = 1160.06
mm
10. Soil Profile Type = SC(UBC-97,Vol-2,Table 16-J)
34. Horizontal Time Period Consider =2 sec (Taking
11. Seismic Coefficient, CV =CVD=0.32 (UBC-97,Vol-2,Table horizontal period to be 2sec)
16-R)
35. Horizontal Frequency, fh= 0.5Hz
12. Seismic Coefficient, Ca=0.24 (UBC-97,Vol-2,Table 16-
Q) fh = ½ = 0.5 Hz
13. Choose Response Reduction Factor, R for =5.5 (UBC- 36. Set Vertical Frequency, fV =10 Hz
97,Vol-2,Table 16-N) 37. So, Shape Factor, S = 8.3333
14. For SMRF/IMRF/OMRF, Structural System =2 (UBC- S = (1/2.4)*(fV/fh)
97,Vol-2,Table A-16-E)
38. Single Layer of Rubber, t = 34.8018 mm
15. Effective Damping (βd orβm) =5%
t = φLRB / 4S
16. Damping Coefficient (Bd orBm) =1 Interpolate (UBC-
97,Vol-2, Table A-16-C) 39. So, Number of Rubber Layer, N = 5.718 ~ 6

17. Design Displacement, Dd= 0.1989m 40. So, Provide Single layer of Rubber = 25 mm
𝑔𝐶𝑉𝐷 𝑇𝐷 (Round up to nearest 5)
DD = 4𝜋 2 𝐵
41. Let, Thickness of Shim Plates =2.8 mm
18. Bearing Effective Stiffness, Keff = 4035.97kN/m
42. Number of Shim Plates, n = 5 n = N-1
𝑊 2𝜋 2
Keff = 𝑥 (𝑇 ) 43. End Plate Thickness is between 19mm to
𝑔 𝐷
38mm,Choose =25 mm
19. Energy Dissipated per Cycle, WD= 50.18kN-m
44. So, Total Height of LRB, h = 214 mm
WD = 2πKeffDD2βeff
45. Bulk Modulus, K = 2000 Mpa
20. Force at Design Displacement or characteristic
strength,= 63.046kN 46. Compression Modulus, EC = 249131.94 kN/m2
Q = WD/4DD EC = 6GS2 (1-(6GS2/K))
21. Pre Yield in Rubber,K2= 3719.14 kN/m 47. Horizontal Stiffness, KH = 3716.1158 kN/m
K2 = Keff – Q/DD KH = GALRB/tf
22. Post Yield Stiffness to Pre Yield Stiffness Ratio (η) for 48. Vertical Stiffness, KV = 1256557.836
Rubber =0.1 kN/m= 1256.5578 MN/m
η = K2/K1 49. Cover From Lead to End Plate = 25 mm
23. Post Yield Stiffness (Value for Non-linear Casealso), 50. Bonded Diameter = 1.11006 m
K1= 37191.43 kN/m
51. Moment of Inertia, I = 74496559729 kN/mm
24. Yield Displacement (Distance from End-J),
DY = 0.00188m Cir: I = πB4/64

DY = Q/(K1 – K2) = 0.07449656 kN/m

25. Recalculation of Force Q to QR = 63.6484 kN 52. Area of Hysteresis Loop, Ah= 49.708 kN/m
𝑊𝐷 Ah = 4Q (Dd – Dy)
QR = 4∗(𝐷
𝐷 − 𝐷𝛾 )
53. Yield Strength, FY = 70.051 kN
26. Yield Strength of Lead, =10 Mpa Fy = Q+K2*Dy

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Reference: UBC-97 & DESIGN OF SEISMIC ISOLATED
STRUCTURE FROM THEORY OF PRACTICE by JAMES
M.KELLY and FARZAD NAEIM

Final input values for ETABS

Table 3: Summary of LRB Parameters in E-tabs
Rotational Inertia 0.074497 kN/m
For U1 Effective Stiffness 4035967 kN/m
For U2 & U3 Effective Stiffness 4035.967 kN/m
For U2 & U3 Effecyive Damping 0.05
For U2 & U3 Distance From End J 0.001884m
For U2 & U3 Stiffness 37191.43 kN/m Fig 7: Details of el-centro Earthquake in X-180
For U2 & U3 Yield Strength 70.05101 kN

6. RESULT OBTAINED FROM ETAB SOFTWARE

All results are computed after analysis of model in
software E-tabs 2017.

Result Obtained From Seismic Load Calculation

Fig 8: Details of el-centro Earthquake in Y-270

Fig 5: Applied Storey Force in Both X & Y Direction

(Fixed Support)

Fig 9: Storey Drift in X-Direction

Fig 6: Applied Storey Force in Both X & Y Direction Fig 10: Storey Drift in Y -Direction
(Base Isolation Support)

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were observed for bottom storey of base isolated
building as compared with fixed base building model.
 From analytical study, it is observed that fixed base
building have zero displacement at base of building.
Whereas, base isolated building models shows
appreciable amount of lateral displacement at base.
 Floor Height increases lateral displacement increases
drastically in fixed base building as compare to base
isolated building. Due to this reduction in lateral
displacement during earthquake damages of
structural as well as non-structural is minimized.
 At base more storey drift was observed for base
Fig 11: Base Force along X-Direction isolated model as compared to model of fixed base
building. As storey height increases, the storey drifts
in base isolation building model drastically decreases
as compared to model of fixed base building.

Acknowledgment
I am extremely thankful and indebted to, almighty, my
family, friends, Dr. Shivakumaraswamy, Dr. S Vijaya, M.
K. Darshan for their constant encouragement without
which this project would not be possible.

References
[1] Salic R. B., Garevski M. A. And Milutinovic Z. V.,
“Response of Lead-Rubber Bearing isolated
Structure,” The 14th World Conference on
Fig 12: Base Force along Y-Direction Earthquake Engineering, October 12-17, 2008,
Beijing, China. J. Clerk Maxwell, A Treatise on
Electricity and Magnetism, 3rd ed., vol. 2. Oxford:
Clarendon, 1892, pp.68-73.
[2] Ms. Minal Ashok Somwanshi and Mrs. Rina N.
Pantawane., “Seismic Analysis of Fixed Based and
Base Isolated Building Structures,” Jawaharlal Darda
Institute of Engineering and Technology, July 22-28,
2015, Yavatmal, Maharashtra, India. K. Elissa, “Title
of paper if known, “unpublished.
[3] R Naveen K, Dr. H. R Prabhakara, Dr. H Eramma.,
“Base Isolation of Mass Irregular RC Multi Storey
Building,” International Research Journal of
Engineering and Technology Vol. 2(07), pp. 2395-
Fig 13: Moment along Z Direction 0072, October 2015, India.
[4] Sunil Shirol, Dr. Jagadish G. Kori, “Seismic Base
CONCLUSION
Isolation of R.C frame structure with and without
 Improvement of base isolation system under extreme
infill” International Research Journal of engineering
excitations, such as
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 It has been observed that maximum shear force,
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@ IJTSRD | Unique Paper ID – IJTSRD33166 | Volume – 4 | Issue – 5 | July-August 2020 Page 1483