International Journal of Engineering Technology, Management and Applied Sciences
www.ijetmas.com March 2017, Volume 5 Issue 3, ISSN 2349-4476
268 Ajitha B & Nirupa N
Analysis & Design of a High Rise Thin Building
Ajitha B1 & Nirupa N
2
1Ajitha, Department of Civil Engineering
, JNTUA College Of Engineering(Autonomous), Ananthapuramu, Andhra
Pradesh, India. 2Nirupa,Department of Civil Engineering
, JNTUA College Of Engineering(Autonomous), Ananthapuramu, Andhra
Pradesh, India.
ABSTRACT
Earthquake load is becoming a great concern in our country as because not a single zone can be designated as
earthquake resistant zone. One of the most important aspects is to construct a building structure, which can resist the
seismic force efficiently. Study is made on the different structural arrangement to find out the most optimized solution to
produce an efficient safe earthquake resistant building.
In the present analysis, a thin building is analyzed with a height of 60m, width of the building is taken as 15m the
building is analyzed without bracings and with X bracings at optimum places and finding out the results of displacement,
shear, moment, in Zone-3 in loose soil for finding the results in both static & response spectrum analysis. A commercial
package of ETABS 2013 has been utilized for analyzing commercial building. The result has been compared using tables
& graph to find out the most optimized solution. Concluding remark has been made on the basis of this analysis.
Keywords: Bracings, Static analysis, Dynamic Analysis.
1. INTRODUCTION
Mankind has always had a fascination for height
and throughout our history we have constantly
sought to metaphorically reach for the stars. From
the ancient pyramids to today’s modern
skyscraper, a civilization’s power and wealth has
been repeatedly expressed through spectacular and
monumental structures. Today the symbol of
economic power and leadership is the skyscraper.
There has been a demonstrated competitiveness
that exists in mankind to proclaim to have the
tallest building in the world. This undying quest
for height has laid out incredible opportunities for
the building profession. From the early moment
frames to today’s ultra-efficient mega-braced
structures, the structural engineering profession
has come a long way. The recent development of
structural analysis and design software coupled
with advances in the finite element method has
allowed the creation of many structural and
architecturally innovative forms. However,
increased reliance on computer analysis is not the
solution to the challenges that lie ahead in the
profession. The basic understanding of structural
behaviour while leveraging on computing tools are
the elements that will change the way structures
are designed and built. The design of skyscrapers
is usually governed by the lateral loads imposed on
the structure. As buildings have taller and
narrower, the structural engineer has been
increasingly challenged to meet the imposed drift
requirements while minimizing the architectural
impact of the structure. In response to this
challenge, the profession has proposed a multitude
of lateral schemes that are now spoken in tall
buildings across the globe. This study seeks to
understand the evolution of the different lateral
systems that have emerged and its associated
structural behaviour, for each lateral scheme
examined, its advantages and disadvantages will
be looked at.
Effect of Soils:
The seismic motion that reaches a structure on the
surface of the earth is influenced by the local soil
conditions. The subsurface soil layers underlying
the building foundation may amplify the response
of the building to earthquake motions originating
in the bedrock. Although it is somewhat difficult
to visualize, it is possible that a number of
underlying soils can have a period similar to the
period of vibration of the structure. Greater
structural distress is likely to occur when the
period of the underlying soil is close to the
fundamental period of the structure. Tall buildings
tend to experience greater structural damage when
they are located on soils having a long period of
motion because of the resonance effect that
develops between the structure and the underlying
soils. If a building resonates in response to ground
motion, its acceleration is amplified.
It is possible that a number of underlying soils
layer s can have a period similar to period of
International Journal of Engineering Technology, Management and Applied Sciences
www.ijetmas.com March 2017, Volume 5 Issue 3, ISSN 2349-4476
269 Ajitha B & Nirupa N
vibration of the structure. Low-to mid-rise
buildings typically have periods in the 0.10 to 1.0
sec range, whereas taller, more flexible buildings
have periods between 1 and 5 sec or greater.
Harder soils and bedrock will efficiently transmit
short-period vibrations(caused by near field
earthquakes)while filtering out longer-period
vibrations (caused by distant earthquakes),
whereas softer soils will transmit longer -period
vibrations. As a building vibrates due to ground
motion, its acceleration will be amplified if the
fundamental period of the building coincides with
the period of vibrations being transmitted through
the soil. Natural period of soil is in the range of 0.5
to 1.0 sec. Therefore, it is entirely possible for the
building and ground to have the same fundamental
period.
As per IS 1893 (Part I) – 2002, soils classification
can be taken as Type – I, Rock or Hard soil: Well
graded gravel and sand mixtures with or without
clay binder and clayey sands poorly graded or sand
clay mixtures, whose N (standard penetration
value) should be above 30. Type – II, Medium
soils: All soils wit h N between 10 and 30, and
poorly- graded sands or gravelly sands with little
or no fines. Type – III, Soft Soils: All soils other
than whose N is less than 10.
Objectives of the Study
To investigate the different ways in which the
tall structures can be stabilized against the effects
of strong horizontal wind loading and seismic
loading. Some other reasons why we use bracings
are tall structures can be constructed which
reduces the area used and we can accommodate a
large population in that particular area. Other
objective is to construct a cost effective structure
in less period of time. This study helps in the
investigation of behaviour of thin high rise
buildings.
The scope is to analyze the thin high rise building
with bracings & without bracings in Zone-3 Type
– III, loose Soils in Static and Dynamic analysis.
Firstly the model is implemented into known
computer software and then it is analyzed based on
the investigation of strength and stiffness.
2. LATERAL LOAD RESISTING SYSTEMS:
A multi-storey building with no lateral bracing is
shown in figure 2.1.When the beams and columns
shown are connected with simple beam
connections, the frame would have practically no
resistance to the lateral forces and become
geometrically unstable. The frame would be
laterally deflect as shown in the below figure even
under a small lateral load.
Loading on tall buildings is different from low-rise
buildings in many ways such as large accumulation
of gravity loads on the floors from top to bottom,
increased significance of wind loading and greater
importance of dynamic effects. Thus, multi-storied
structures need correct assessment of loads for safe
and economical design. Excepting dead loads, the
assessment of loads cannot be done accurately.
Live loads can be anticipated approximately from a
combination of experience and the previous field
observations. But, wind and earthquake loads are
random in nature. It is difficult to predict them
exactly. These are estimated based on probabilistic
approach. The following discussion describes the
influence of the most common kinds of loads on multi-
storied structures.
2.1 STRUCTURAL CONCEPTS: The key idea in conceptualizing the structural system
for a narrow tall building is to think of it as a beam
cantilevering from the earth (fig 2.2).
Figure 2.1.1:Structural concept of tall building The
laterally directed force generated, either due to wind
blowing against the building or due to the inertia forces
induced by ground shaking, tends both to snap it
(shear), and push it over (bending).
Figure 2.1 : multi- storey frame
without lateral bracing
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270 Ajitha B & Nirupa N
Therefore, the building must have a system to
resist shear as well as bending. In resisting shear
forces, the building must not break by shearing off
and must not strain beyond the limit of elastic
recovery.
Figure 2.1.2: Building shear resistance;
(a) Building must not break
(b) Building must not deflect excessively in shear.
Figure 2.1.3: Bending resistance of building
(a)Building must not overturn
(b)Columns must not fail in tension or
compression
(c) Bending deflection must not be excessive.
In the structure’s resistance to-of bending-war
ensues that sets and the shear building in motion,
thus creating a third engineering problem; motion
perception or Vibration. If the building sways too
much, human comfort is sacrificed, or more
importantly, non-structural elements may break
resulting in expensive damage to the building
contents and causing danger to the pedestrians.
A perfect structural form to resist the effects of
bending, shear and excessive vibration is a system
possessing vertical continuity ideally located at the
farthest extremity from the geometric centre of the
building. A concrete chimney is perhaps an ideal,
if not an inspiring engineering model for a rational
super-tall structural form. The quest for the best
solution lies in translating the ideal form of the
chimney into a more practical skeletal structure.
2.2 LATERAL FORCE RESISTING
SYSTEMS: There are several systems that can be used
effectively for providing resistance to seismic
lateral forces. Some of the more common systems
are shown in figures below. All of the systems rely
on a complete, three–dimensional space frame; a
coordinated system of moment frames, shear
walls, or braced frames with horizontal
diaphragms; or a combination of the systems.
1. In buildings where a space frame resists the
earthquake forces, the columns and beams act in
bending. During a large earthquake, storey to
storey deflection may be accommodated within the
structural systems without causing failure of
columns or beams. However, the drift may be
sufficient damage elements that are rigidly tied to
the structural system such as brittle partitions,
stairways, plumbing, exterior walls, and other
elements that extend between floors. Therefore,
buildings can have substantial interior and exterior
non structural damage and still be structurally safe.
Although there are excellent theoretical and
economic reasons for resisting seismic forces by
frame
2. A shear wall (or braced frame) building is
normally more rigid than a framed structure. With
low design stress limits in shear walls, deflection
due to shear forces is relatively small. Shear wall
construction is an economical method of bracing
buildings to limit damage, and this type of
construction is normally economically feasible up
to about 15 stories. Notable exceptions to the
excellent performance of shear walls occurs when
the height-to-width ratio becomes great enough to
make overturning a problem and when there are
excessive openings in the shear walls. Also, if the
soil beneath its footings is relatively soft, the entire
shear wall may rotate, causing localized damage
around the wall.
3. The structural systems just mentioned may be
used singly or in combination with each other.
When frames and shear walls interact, the system
is called a dual system in the frame alone can resist
25% of the lateral load. Otherwise, it is referred to
as a combined system
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271 Ajitha B & Nirupa N
Figure 2.2.1 : Lateral-force-resisting systems: (a)
steel moment-resisting frame; (b) reinforced
concrete moment-resisting frame; (c) braced steel
frame; (d) reinforced concrete shear walls; (e) steel
frame building with cast-in-place concrete shear
walls; (f) steel frame building with infilled walls of
non reinforced masonry.
3. BRACED FRAMES: Rigid frame systems are not efficient for
buildings taller than about 30-stories because the
shear racking component of deflection due to the
bending of columns are girders causes the drift to
be too large. A braced frame attempts to improve
upon the efficiency of a rigid frame by virtually
eliminating the bending of columns and girders.
This is achieved by adding web members such as
diagonals or chevron braces. The horizontal shear
is now primarily absorbed by the web and not by
the columns. The webs carry the lateral shear
predominantly by the horizontal component of
axial action allowing for nearly a pure cantilever
behaviour.
In simple terms, braced frames may be
considered as cantilevered vertical trusses resisting
lateral loads primarily through the axial stiffness
of columns and braces. The columns act as a chord
in resisting the overturning moment, with tension
in the windward column and compression in the
leeward column. The diagonals and girders work
as the web members in resisting the horizontal
shear, with diagonals in axial compression or
tension depending upon their direction of
inclination. The girders act axially, when the
system is a fully triangulated truss. They undergo
bending also when the braces are eccentrically
connected to them. Because the lateral load on the
building is reversible, braces are subjected in turn,
to both compression and tension; consequently,
they are most often designed for the more stringent
case of compression.
Figure 3.1 : Braced frame deformation
(a) flexural deformation
(b) shear deformation;
(c) Combined configuration
The effect of axial deformation of configuration of
the deflection with concavity downward and a
maximum slope at the top (Fig-a). The axial
deformations of the web members, on the other
hand, cause a “shear” configuration at the top (Fig-
b ). The resulting deflected shape of the frame
(Fig-c) is a combination of the effects of the
flexural and shear curves, with a resultant
configuration depending on their relative
magnitudes, as determined mainly by the type of
bracings. Nevertheless, it is the flexural deflection
that most often dominates the deflection
characteristics.
The role of web members in resisting shear can be
demonstrated by following the path of the
horizontal shear down the brace bent. Consider the
brace frames shown subjected to an external shear
force at the top level, the diagonal in each storey is
in compression, causing the beams to be in axial
tension; therefore, the shortening of the diagonal
and extension of the beams give rise to the shear
deformation of the bent. In the forces in the brace
connecting to each beam-end are in equilibrium
horizontally with the beam carrying insignificant
axial load, half of each beam is in compression
while the other half is in tension. the braces are
alternatively in compression and tension while the
beams remain basically unstressed. Finally, in
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272 Ajitha B & Nirupa N
Fig3.6e, the end parts of the beam are in
compression and tension with the entire beam
subjected to double curvature bending. Observe
that with a reversal in the direction of horizontal
load, all actions and deformations in each member
will also be reversed.
4. MATERIALS & METHODS:
4.1 Plan Considered:
In this study an 35 storey building having same
plan in different type of zones (as per IS 1893
(Part I): 2002) and different type of soils is taken.
The tall building with X braces introduce in the
central location in two bays is consider to study
the effect of lateral deflection, bending moment,
shear force caused due to lateral load. i.e. due to
quake load (both static and dynamic).
4.2. Building Dimensions:
The building is 15m x 60m in plan with columns
spaced at 5m from centre to centre. A floor to floor
height of 3.0m is assumed. The location of the
building is assumed to be in Zone-3 and loose
soils.
Table 4.2.1: Size of Structural Members
4.3. Modeling :
To create a model firstly we have to form a grid.
Grid can be of uniform or non uniform. Uniform
refers to spacing which are in equal distances in
global x direction & equal distances in global Y
direction. It is not compulsory to make same
distances in both the global directions.
4.4.Defining Frame Sections and Slab sections:
After forming the grid we have to define frame
sections which includes beam & column. In this
software we can define a column with suitable
reinforcement which can be edited if the provided
reinforcement exceeds the limit. Beam defining &
Column defining is shown in below figures.
Figure 4.4.1 : Showing Defining of Beam
Figure 4.4.2 : Showing Defining of Column
Figure 4.4.3 :Showing reinforcement details for column
Figure 4.4.4 : Showing defining of slab
section 4.5 Loading: After the modeling is complete, ETABS generates
code-based loading conditions for gravity, seismic,
wind loads. We can specify an unlimited number
of load patterns and combinations. Load patterns in ETABS software:
Sr.
No. Contents Description
1 Size of column
From ground floor to
fifteenth floor: 1000
mm X 900 mm
From sixteenth floor to
thirty fifth floor: 900
mm X 600 mm
2 Size of beam 400 mm X 600 mm
3 Thickness of Slab
120 mm
4 Size of Brace
Members 230 mm X 230 mm
5 Materials
Concrete (M30) and
Reinforcement HYSD 500
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273 Ajitha B & Nirupa N
Figure:4.5.1 Showing loads to be
applied on structure
Figure4.5.2: Showing of defining Load Combinations
And also model is analyzed in dynamic analysis by
response spectrum method.
4.6. Response Spectrum Method: Response spectrum method is simple when
compared to time history method, in this method
model is placed in particular zone & soil and we
see the behaviour of model or a building for that
particular earthquake zone & soil. Earth Quake
Data Is Referred from IS 1893-2002
Table 4.6.1 : Zone Factors in India
4.7. Analysis & Design:
Output and display formats are also practical and
intuitive. Moment, shear, and axial force diagrams,
presented in 2D and 3D views with corresponding
data sets, may be organized into customizable
reports. Also available are detailed section cuts
depicting various local response measures.
ETABS also features interoperability with related
software products, providing for the import of
architectural models from various technical
drawing software, or export to various platforms
and file formats. SAFE, the floor and foundation
slab design software with post-tensioning (PT)
capability, is one such option for
export. CSI coordinated SAFE to be used in
conjunction with ETABS such that engineers
could more thoroughly detail, analyze, and design
the individual levels of an ETABS model.
While ETABS features a variety of sophisticated
capabilities, the software is equally useful for
designing basic systems. ETABS is the practical
choice for all grid-like applications ranging from
simple 2D frames to the most complex high rises.
4.8.PLAN AND ELEVATION OF MODEL:
A simple plan of 150m X 60m is taken, with 5
bays of 8 m each as shown below.
Figure 4.8.1 : Building plan dimension(Common to
all floors, all models, units m‟).
Figure 4.8.2: Showing elevation view of high rise
building
ZONES ZONE
FACTOR
ZONE-II 0.10
ZONE-III 0.16
ZONE-IV 0.24
ZONE-V 0.36
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274 Ajitha B & Nirupa N
5.RESULTS: Table-1: Comparative values of Displacement in
Zone-3 loose soil in Static Analysis
Graph 1 : Displacement variationin Zone-3 loose soil
in Static Analysis
Table-2: Comparative values of Displacement in
Zone-3 loose soil in Dynamic Analysis
Graph 2 : Showing Displacement variation
in Zone-3 loose soil in Dynamic Analysis
Storey
Without
Bracings
With
Bracings
Storey35 26.4 22.8
Storey34 26.1 22.4
Storey33 26 22.2
Storey32 25.9 22
Storey31 25.7 21.8
Storey30 25.5 21.5
Storey29 25.1 21.2
Storey28 24.7 20.8
Storey27 24.2 20.3
Storey26 23.6 19.8
Storey25 23 19.3
Storey24 22.3 18.7
Storey23 21.6 18.1
Storey22 20.8 17.4
Storey21 20 16.7
Storey20 19.1 15.9
Storey19 18.1 15.1
Storey18 17.2 14.3
Storey17 16.2 13.5
Storey16 15.3 12.7
Storey15 14.3 11.9
Storey14 13.3 11.1
Storey13 12.3 10.3
Storey12 11.2 9.4
Storey11 10.2 8.6
Storey10 9.2 7.8
Storey9 8.2 7
Storey8 7.2 6.2
Storey7 6.1 5.4
Storey6 5.1 4.6
Storey5 4.1 3.8
Storey4 3.1 3.1
Storey3 2.1 2.3
storey2 1.2 1.5
Storey1 0.4 0.7
Base 0 0
Storey
Without
Bracings
With
Bracings
Storey35 45 38.2
Storey34 44.5 37.7
Storey33 44.3 37.3
Storey32 44 36.9
Storey31 43.6 36.4
Storey30 43 35.8
Storey29 42.3 35.2
Storey28 41.5 34.4
Storey27 40.5 33.6
Storey26 39.5 32.7
Storey25 38.4 31.8
Storey24 37.2 30.7
Storey23 35.9 29.6
Storey22 34.5 28.5
Storey21 33 27.3
Storey20 31.5 26.1
Storey19 30 24.8
Storey18 28.4 23.5
Storey17 26.9 22.2
Storey16 25.3 20.8
Storey15 23.6 19.5
Storey14 22 18.1
Storey13 20.3 16.8
Storey12 18.7 15.4
Storey11 17 14.1
Storey10 15.3 12.7
Storey9 13.6 11.4
Storey8 11.9 10
Storey7 10.2 8.7
Storey6 8.5 7.4
Storey5 6.8 6.1
Storey4 5.2 4.9
Storey3 3.5 3.6
storey2 2 2.3
Storey1 0.7 1
Base 0 0
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275 Ajitha B & Nirupa N
Table-3: Comparative values of Shear in
Zone-3 loose soil in Static Analysis
Graph 3 : Showing Shear variation
in Zone-3 loose soil in Static Analysis
Table-4:Comparative values of Shear in Zone-
3 loose soil in Dynamic Analysis
Graph 4 : Showing Shear variation
in Zone-3 loose soil in Dynamic Analysis
Storey
Without
Bracings
With
Bracings
Storey35 79.5 30.76
Storey34 58.7 21.84
Storey33 61.1 22.9
Storey32 60.4 22.8
Storey31 60.06 22.9
Storey30 59.5 23.16
Storey29 58.86 23.38
Storey28 58.12 23.62
Storey27 57.2 23.87
Storey26 56.3 24.11
Storey25 55.2 24.33
Storey24 54.1 24.56
Storey23 52.6 24.67
Storey22 41.5 25.4
Storey21 59.4 21.11
Storey20 57.6 35.46
Storey19 57.4 28.59
Storey18 55.1 29.9
Storey17 53.3 29.88
Storey16 51.8 29.96
Storey15 50.2 29.98
Storey14 48.5 29.97
Storey13 46.7 29.94
Storey12 44.8 29.85
Storey11 42.7 29.92
Storey10 40.6 29.53
Storey9 38.3 29.3
Storey8 35.9 28.9
Storey7 33.4 28.42
Storey6 30.7 27.01
Storey5 27.7 25.99
Storey4 26.9 25.01
Storey3 22.4 19.72
storey2 19.6 25.97
Storey1 18.5 12.3
Base 14.5 11.4
Storey
Without
Bracings
With
Bracings
Storey35 8.3 30.76
Storey34 58.7 21.84
Storey33 61.1 22.9
Storey32 60.4 22.8
Storey31 60.06 22.9
Storey30 59.5 23.16
Storey29 58.86 23.38
Storey28 58.12 23.62
Storey27 57.2 23.87
Storey26 56.3 24.11
Storey25 55.2 24.33
Storey24 54.1 24.56
Storey23 52.6 24.67
Storey22 41.5 25.4
Storey21 59.4 21.11
Storey20 57.6 35.46
Storey19 57.4 28.59
Storey18 55.1 29.9
Storey17 53.3 29.88
Storey16 51.8 29.96
Storey15 50.2 29.98
Storey14 48.5 29.97
Storey13 46.7 29.94
Storey12 44.8 29.85
Storey11 42.7 29.92
Storey10 40.6 29.53
Storey9 38.3 29.3
Storey8 35.9 28.9
Storey7 33.4 28.42
Storey6 30.7 27.01
Storey5 27.7 25.99
Storey4 26.9 25.01
Storey3 22.4 19.72
storey2 19.6 25.97
Storey1 18.5 12.3
Base 14.5 11.4
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276 Ajitha B & Nirupa N
Table-5: Comparative values of Moment in
Zone-3 loose soil in Static Analysis
Graph 5 : Showing Moment variation in Zone-3 loose
soil in Analysis
Table-6:Comparative values of Moment in
Zone-3 loose soil in Dynamic Analysis
Graph 6 : Showing Moment variation in Zone-3 loose
soil in Dynamic Analysis
Storey
Without
Bracings
With
Bracings
Storey35 97 37
Storey34 93.4 47.6
Storey33 64.5 25.9
Storey32 61.3 24.5
Storey31 57.5 22.27
Storey30 54.5 20.67
Storey29 51.5 19.2
Storey28 48.6 17.9
Storey27 45.7 16.7
Storey26 42.8 15.6
Storey25 39.9 14.6
Storey24 37 13.6
Storey23 34.1 12.6
Storey22 31.3 11.7
Storey21 27.8 10.9
Storey20 24.2 11.3
Storey19 48.2 14.7
Storey18 18.7 1.4
Storey17 1 8.6 4.8
Storey16 18.1 5.3
Storey15 16.4 5.3
Storey14 14.6 5.2
Storey13 12.7 5.1
Storey12 10.8 4.9
Storey11 0.7 4.6
Storey10 6.6 4.3
Storey9 4.3 3.9
Storey8 1.9 3.4
Storey7 4.5 2.8
Storey6 10.4 4.9
Storey5 16.9 7.93
Storey4 24.9 11.56
Storey3 36.8 16.4
storey2 59.9 24.9
Storey1 114.221 58.2
Base 265.97 293.5
Storey
Without
Bracings
With
Bracings
Storey35 90 35.45
Storey34 65.14 32.4
Storey33 62.8 36.32
Storey32 59.92 33.23
Storey31 57.74 30.01
Storey30 55.53 28.43
Storey29 53.31 29.43
Storey28 51.06 25.3
Storey27 48.79 22.32
Storey26 46.48 21.2
Storey25 44.12 20.33
Storey24 41.71 20.12
Storey23 39.26 19.85
Storey22 36.37 19.23
Storey21 34.09 19.55
Storey20 56.46 18.44
Storey19 32.3 17.43
Storey18 31 16.7
Storey17 30.21 18.5
Storey16 28.7 17.44
Storey15 27.07 16.88
Storey14 25.35 18.76
Storey13 23.55 19.33
Storey12 21.65 16.32
Storey11 19.65 15.6
Storey10 17.54 13.22
Storey9 15.3 12.1
Storey8 12.944 10.2
Storey7 10.5 8.6
Storey6 8.09 6.5
Storey5 6.07 4.32
Storey4 4 3.22
Storey3 4.09 3.221
storey2 3.65 2.1
Storey1 3.6 3.2
Base 3 2.1
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277 Ajitha B & Nirupa N
(a)
(b)
Figure 6.1 : The variation of (a)Shear (b)Moment
in 3D View
4. CONCLUSIONS:
Based on the analysis:
In static analysisThe structural
performance is analyzed in two different
models i.e. Without bracings, With X
Bracing, the displacement of 40% is
reduced when lateral systems are
provided.
Shear is also analyzed for both the models,
Shear of 30% is reduced when the lateral
systems i.e., X bracings are provided.
Moment is also compared for both the
models, moment of 60% is reduced when
x bracings are provided.
By providing the bracings the stiffness of
the structure is increased and storey shear
is decreased with increase in height of
structure.
Dynamic Analysis i.e.. Response
Spectrum analysis is performed for all the
models i.e. without bracings & with
bracings. The displacement of 40% is
reduced when X bracings are provided
Dynamic Analysis i.e.. Response
Spectrum analysis is carried out for all the
models i.e. without bracings & with
bracings. A shear of 30% is reduced when
X bracings are provided.
Dynamic Analysis i.e.. Response
Spectrum analysis is carried out for all the
models i.e. without bracings & with
bracings. A moment of 40% is reduced
when X bracings are provided.
By providing lateral systems in the framed
structures the reduction in the
displacement, shear, moment thereby
increasing the stiffness of the structure for
resisting lateral loads due to earth quakes
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