International Journal of Civil Engineering and Technology (IJCIET)
Volume 10, Issue 04, April 2019, pp. 821–829, Article ID: IJCIET_10_04_087
Available online at http://www.iaeme.com/ijmet/issues.asp?JType=IJCIET&VType=10&IType=4
ISSN Print: 0976-6308 and ISSN Online: 0976-6316
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OPTIMIZATION OF BRACING AND VISCOUS
DAMPER AND COMPARISON OF FLUID
VISCOUS DAMPER AND BRACING SYSTEM
FOR STABILIZATION OF HIGH RISE
BUILDING
Amanullah
PG Student of Civil Engineering, Chandigarh University,
Mohali, Punjab, India
Sahil Arora
Assistant Professor, Department of Civil Engineering,
Chandigarh University, Gharaun, Punjab, India
ABSTRACT
Basically in case of tall building lateral loads i.e. earthquake and wind always
governing the design. So, to counteract these loads, a proper lateral load resisting
system should be used to fulfill design and serviceability criteria. Lateral bracing and
fluid viscous damper are among those system which can be used to fulfill strength and
latera stiffness criteria. In this paper a 20 story reinforced concrete building has been
modeled in standard package ETABS 2016 for the purpose of study. Total of 6 models
have been made, bare frame, bracing with its type and fluid viscous damper. Also
equivalent static and linear response spectrum analysis have been performed to
capture accurate response of structure. For seismic efficiency base shear, time period
and lateral deflection of each model have found and compared with each other.
Key words: fluid viscous damper, bracing, base shear, time period and lateral
deflection.
Cite this Article: Amanullah and Sahil Arora, Optimization of Bracing and Viscous
Damper and Comparison of Fluid Viscous Damper and Bracing System for
Stabilization of High Rise Building, International Journal of Civil Engineering and
Technology 10(4), 2019, pp. 821–829.
http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=10&IType=4
1. INTRODUCTION
In these demand for construction of high rise building increases day by day due rapid
urbanization and shortage of land in urban areas. For tall building there is always need of
proper structural system to transfer lateral and gravity loads to foundation system. There are
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Amanullah and Sahil Arora
numbers of structural system available which usually used for stabilization of high rise
building some of them are as follow: outrigger system, tube system, bundled tube system,
core shear wall system, bracing system, fluid viscous damper system…etc. Among them
lateral bracing system frequently used for structures up to 30 to 40 story building in order to
increase its lateral strength and stiffness to fulfill serviceability and design criteria. Mainly
there are two types of bracing concentric bracing and eccentric bracing. Concentric bracing
can be in various shape such as X-bracing, V-bracing and inverted V-bracing. In recent years
fluid viscous damper which is a new technique used for lateral load resisting system for tall
building. There are various fluid viscous damper with different capacity in the market which
can be used for lateral load resisting system. In this paper both method bracing and fluid
viscous damper are used in order to increase lateral strength and reduce lateral deflection.
2. BRACING SYSTEM
Steel bracing is very efficient structural system to transfer lateral forces to columns. Steel
bracing transfer lateral loads i.e. earthquake and wind by means of tension-compression
action. Therefore it utilize axial load carrying capacity of bracing and need minimum size of
member. Steel bracing is used in numbers of high-rise building in the past to stabilize building
against lateral loads. This system has less base shear as compare to core shear wall structural
system. Also bracing system is one of the most effective technique which used in retrofitting
of building in order to increase its lateral load carrying capacity and reduce lateral deflection
of building. Slenderness ration of steel bracing system is the prominent factor for overall
performance of structure; bracing with low value of slenderness ratio leads to poor
performance of structural system, on the other hand bracing with high value of slenderness
ration makes system too rigid and attract more earthquake forces. Therefor for a better
performance of structure system, slenderness ratio of bracing has to be optimized. In general
there are two types of bracing system, concentric bracing system and eccentric bracing
system. Eccentric bracing system used where beams are having high flexural stiffness and
flexural strength. Concentric bracing is of many shape, like X-bracing, V-bracing, inverted Vbracing…etc. Among them X-bracing is the simplest type and frequently used as a lateral load
resisting system.
3. DAMPER
Damper is one of the very effective technique for energy dissipation, and widely used now
days for lateral load resisting system. Though this new technique is expensive than other
structural system, but using of this system dissipate the energy and reduce the base shear
significantly as compare to core shear wall, bracing and other structural system . There are
different types of damper available, some of them are as follow: pall friction damper, fluid
viscous damper, PVD damper, friction damper.
4. PALL FRICTION DAMPER
Pall friction damper frequently used as lateral load resisting system. Pall friction damper
consist of following component: steel plate, bracing and high strength bolts. Working
principle of this system is simple, bracing and steel plates are connected together with the
help high strength bolts which are allowed to slip under earthquake and wind loads which
dissipate energy. When earthquake or wind hit the building pall friction damper slip and
dissipate lateral energy of system and building behave elastic, therefore avoid damage to
building. This system significantly reduce base shear and lead to small size of beam, column
and foundation which reduce the overall cost. Figure 1 shows pall friction damper.
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Optimization of Bracing and Viscous Damper and Comparison of Fluid Viscous Damper and
Bracing System for Stabilization of High Rise Building
5. FLUID VISCOUS DAMPER
Fluid viscous damper is a new technique which used for stabilization of buildings against
lateral forces. In recent years this technique frequently used as lateral load resisting system,
particularly for retrofitting of buildings. Fluid viscous damper consist of three main
component: 1-cylender, 2-piston, 3-viscous fluid. When fluid viscous damper subject to any
lateral force, piston rod create reciprocating motion in the cylinder to force damping medium
move back and forth and dissipate the lateral energy. Installation of this system is easy, and
can be installed in diagonal, V- shape and inverted V form. Fluid viscous damper is available
with different load carrying capacity; for example 250KN, 500KN, 750KN, 1000KN,
1500KN, 2000KN, 3000KN, 6500KN and 8000KN. In this paper FVD of 250KN, 500KN
and 750KN is used. Figure 2 shows viscous fluid damper.[4]
6. FRICTION DAMPER
Friction damper is another type of damper which dissipate the seismic energy by means of
friction between contacted surfaces of two steel plate. Ease of installation and simple
geometry make this system effective and used frequently for lateral load resisting system. figu
Figure 1 Pall friction damper [4]
Figure 2.Viscous fluid damper [8]
7. MODELING AND ANALYSIS
In this paper a 20 story reinforced concrete building with total height of 70m, and plan size of
40x20m, with 5 bay each of 5m along y- axis and 7 bay with spacing of 5m, 6m and 5.5m
along x-axis is modeled in ETABS 2016. According to clause 7.5.2 of IS 1893(Part1):2002,
symmetrical buildings which are located in zone IV and V and are having height 40m or more
need dynamic analysis. So, in current situation height of building is 70m and building is
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located in zone IV which need dynamic analysis. This building is analyzed by equivalent
static and linear dynamic response spectrum method. In current situation 6 model of the same
building is modeled and different types of bracing and fluid viscous damper used. Loading,
load combination and all building component sizes are same for all models. All models are
analyzed by equivalent static and linear dynamic response spectrum analysis. Table 1, 2, 3,
and 4 shows geometrical parameter, load combination, loading and seismic parameter
respectively. Figure 3 and 4 shows the plan and 3d of the model.
7.1. Structure Parameters
Table 1 Geometrical parameter
Sr.no Column size Beam size Total
Story
Slab
Bracing
in mm
in mm height in height in thickness size is
m
m
in mm
ISHB
1
700x500
500x400
70
3.5
150
250-1
Grade of Grade of
concrete
steel
M35
Fe500
Table 2 Load Combination
Load combination
DL+LL
1.5(DL+LL)
1.2(DL+LL+EQ X)
1.2(DL+LL-EQ X)
1.2(DL+LL+EQ Y)
1.2(DL+LL-EQ Y)
1.5(DL+EQ X)
1.5(DL-EQ X)
1.5(DL+EQ Y)
1.5(DL-EQ Y)
0.9DL+1.5EQX
0.9DL-1.5EQX
0.9DL+1.5EQY
0.9DL-1.5EQY
DL
1.0
1.5
1.2
1.2
1.2
1.2
1.5
1.5
1.5
1.5
0.9
0.9
0.9
0.9
LL
1.0
1.5
1.2
1.2
1.2
1.2
-
EQ X
1.2
1.2
1.5
1.5
1.5
EQ Y
1.2
1.2
1.5
1.5
-
-
1.5
1.5
Table 3 Loading
Sr.no
1
Live load in KN/M^2
3
Super dead load in KN/M^2
3
Wall load in KN/M
15
Table 4 Seismic parameters
Sr.no
Importance
factor(I)
Zone factor(Z)
1
1.5
0.24
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Response
reduction
factor(R)
5
Type of soil
medium
Damping ratio
II
5%
editor@iaeme.com
Optimization of Bracing and Viscous Damper and Comparison of Fluid Viscous Damper and
Bracing System for Stabilization of High Rise Building
Figure 3. Plan View
Figure 4. 3 D view

Mod1= Bare frame

Mod2= X bracing

Mod3= Inverted V bracing

Mod4= Diagonal FVD 250KN

Mod5= FVD 750 KN inverted V shape

Mod6= FVD 500 KN inverted V shape
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… Mod 2
Mod 1…
…
Mod 3
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Mod 4
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Optimization of Bracing and Viscous Damper and Comparison of Fluid Viscous Damper and
Bracing System for Stabilization of High Rise Building
Mod 5
Mod 6
8. RESULT AND DISCUSSION
In present study all models have been analyzed by ETABS 2016. Coefficient or static method
and response spectrum method of seismic analysis have been performed for all models, and
base shear in response spectrum has been scaled up more than 85% of its static base shear.
Base shear, lateral deflection and time period of all models have found out and shown in
graph 1, 2 and 3 respectively. Model 2 which is X- bracing has the maximum base shear of
4167KN and model 4 which is diagonal fvd 250kn has the minimum base shear of 1709 KN,
which shows 58.98% reduction as compare to X- bracing. Graph 2 shows lateral deflection of
all models. In this model 6 has the maximum lateral deflection of 142.8mm and model 3 has
the minimum lateral deflection of 122.2mm, which shows 14.4% reduction in lateral
deflection as compare to model 6. Graph 3 represent time period of all models, among all
models, model 1 has the maximum time period of 3.86 second which indicate that it is more
flexible and model 4 has the minimum time period of 2.94 second which is more stiff as
compare to other models.
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Graph 1 Base shear
Graph 2 Lateral deflection
Graph 3 Time period
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Optimization of Bracing and Viscous Damper and Comparison of Fluid Viscous Damper and
Bracing System for Stabilization of High Rise Building
9. CONCLUSIONS
On the bases of present study following result has been constructed:
1- A proper lateral load resisting system is required to increase lateral strength and stiffness of
high-rise buildings.
2- In present study two types of bracing i.e. X-bracing and inverted V-bracing are used as a
lateral load resisting system which reduced lateral displacement from 132.5mm in bare frame
to 122.2mm, reduced time period from 3.86 sec to 3.2sec, but increased base shear from 3169
KN to 4167 KN which is not a desirable situation.
3- In this paper three types of fluid damper used with capacities 250 KN, 500 KN and 750
KN. Using of fluid viscous damper with capacities 500KN and 750 KN did not contribute to
lateral stiffness of the structure, instead increased latera deflection from 132.5mm to 138.5mm
in case of FVD500 and from 132.5mm to 142.8mm in case of FVD750. But fluid viscous
damper with capacity of 250KN had significant effect in overall performance of structure. It
reduced time period from 3.86sec in case of bare frame to 2.94sec, base shear from 3169 KN
in case of bare frame to 1709KN and lateral deflection from 132.5mm to 122.7mm.
4- In overall comparison of bare frame, bracing system and fluid viscous damper, fluid
viscous damper with 250KN capacity has good structural performance as compare to other
systems.
REFERENCES
[1]
Stuctural analysis and design of tall buildings by Bungal S.Taranat. CRC press, 2010 by
Taylor & Francis group Boca Raton London, New York.
[2]
IS1893 (Part1):2002
[3]
A study on bracing system on high rise steel structures by Jagadish J.S and Tejas D.
Doshi, international journal of engineering research and technology (IJERT) ISSN:22780181, VOL.2 Issue 7, July -2013.
[4]
Seismic response study of multi-storied reinforced concrete building with fluid viscous
dampers by Shaik Qamaruddin, research gate, January -2017.
[5]
Evaluation of pall friction damper performance in near-fault earthquakes by using of nonlinear time history analysis by Kolsum Jafarzadeh, Mohammad Ali Lotfollahi-Yaghin and
Rasoul Sabetahd, world applied sciences journal 20(2):264-270-ISSN: 1818-4952. 2012.
[6]
Effect of fluid viscous dampers in multi-storied buildings by LEYA MATHEW and
C.PRABHA, internal journal of research in engineering and technology (IJRET). ISSN
(E):2321-8843; ISSN (P): 2347-4599. Vol. 2, Issue 9, 55-60. Sep 2014.
[7]
Seismic analysis of reinforced concrete frame with steel bracings by Abhijeet Baikerikar;
international journal of research in engineering and technology (IJERT); ISSN: 22780181. Vol. 3 Issue 9, September-2014.
[8]
Testing of fluid viscous damper by fegn qian and sunwei ding, jingjing song, 15 WCEE,
LISBOA 2012.
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