IRJET-A Comparative Study of Different Configuration of Shear Wall Location in Soft Story Building Subjected to Seismic Load.

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During earthquake RC (Reinforced Concrete) structures are subjected to lateral displacement. Most of the RC structures are designed to resist gravity loads only neglecting the effect of lateral forces arising due to earthquake. This study is concentrated to analyze the seismic behavior of structure (Special Moment Resisting Frame, SMRF). The study has been carried out using STAAD.PRO software, IS 1893:2002, IS 13920:1993 and IS 456:2000. The building under analysis consist of 11 floors and has 5 bays along both direction with a span of 4m each, floor to floor height is 3m, ground floor to first floor height is 2.80m. The building has been to be located in seismic zone- II (Bhilai region, Chhattisgarh) of India. While analyzing using STAAD.PRO, soft storey has been observed at 1st and 11th floor. A comparative has been done by placing shear wall at different location in the building subjected to seismic load. These locations consist of shear wall being placed at periphery, at intermediate position and in the core.

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International Research Journal of Engineering and Technology (IRJET)
Volume: 02 Issue: 07 | Oct-2015

www.irjet.net

e-ISSN: 2395 -0056
p-ISSN: 2395-0072

A Comparative Study of Different Configuration of Shear Wall Location
in Soft Story Building Subjected to Seismic Load.
R.S.Mishra1, V.Kushwaha2, S.Kumar3
1 2 3Assistant

Professor, Civil Engineering Department, SSITM Bhilai

---------------------------------------------------------------------***--------------------------------------------------------------------Abstract — During earthquake RC (Reinforced
Concrete) structures are subjected to lateral
displacement. Most of the RC structures are designed to
resist gravity loads only neglecting the effect of lateral
forces arising due to earthquake. This study is
concentrated to analyze the seismic behavior of
structure (Special Moment Resisting Frame, SMRF). The
study has been carried out using STAAD.PRO software,
IS 1893:2002, IS 13920:1993 and IS 456:2000. The
building under analysis consist of 11 floors and has 5
bays along both direction with a span of 4m each, floor
to floor height is 3m, ground floor to first floor height is
2.80m. The building has been to be located in seismic
zone- II (Bhilai region, Chhattisgarh) of India. While
analyzing using STAAD.PRO, soft storey has been
observed at 1st and 11th floor. A comparative has been
done by placing shear wall at different location in the
building subjected to seismic load. These locations
consist of shear wall being placed at periphery, at
intermediate position and in the core.

Key Words: Drift, Seismic Force, Shear Wall, Soft
Storey, STAAD.Pro, Stiffness.
1. INTRODUCTION
Soft story or stilt storey is a feature which can be seen
frequently in India and abroad also, generally used for
parking or retail purpose.These are basically ground story
which consists of only columns without any pattern wall.
Soft storey is one in which lateral stiffness is less than
70% of that in story above or less than 80% of average
lateral stiffness of three stories above (IS 1893 Part-I,
2002) [1]. It has been observed that soft storey buildings
are easily vulnerable to damage under the effect of seismic
forces.
It doesn’t meet the minimum bare requirement with
respect to drift and stiffness. With respect to floors above
the soft storey shows larger flexibility and hence larger
displacement under the effect of seismic forces. When
subjected to seismic loads the upper
© 2015, IRJET

stories move almost together as a single block and hence
most of horizontal displacement of building occurs in soft
story which causes failure of structure due to excessive
drift. During the earthquake the dynamic ductility demand
gets intense in soft storey and upper storey tends to
remain elastic. This is where the importance of shear wall
comes into picture.
Shear wall is vertical structure member which can resist
moment, shear and axial load arising due to gravity and
lateral (earthquake) load. It offers adequate rigidity for
lateral load resistance and provides sufficient stiffness to
whole structure. Mark Fintel, a noted civil engineer in
U.S.A said “We cannot afford to build concrete buildings
meant to resist severe earthquake without shear wall”.
Structure with shear wall offer significant reduction in
lateral sway. Apart from structural advantages shear walls
are cost efficient also. Misam.A and MangulkarMadhuri.N
et al [2] investigated the addition of shear wall to the
building in different arrangement in order to reduce soft
storey effect on structural seismic response and
recommended that location and numbering of shear wall
acts as an important factor for the soft storey structures to
displace during earthquake. G.V.S.Siva Prasad and
S.Adiseshu et al [3] developed a new method and analysis
of shear wall framing system and a new model to compare
the safety of structure and cost effectiveness structure for
a lateral loading system for a tall and high rise structure.

2. STRUCTURAL PROPERTIES OF RC BUILDING













stories – G+11
Storey height – 3m
Beam dimension – 0.25m*0.25m
Inner column dimension – 0.35m*0.35m
Outer column dimension – 0.40m*0.40m
Shear wall thickness – 0.20m
Grade of concrete – M30
Grade of steel (IS) – Fe 415
Fck – 30 N/mm2
Fy – 500 N/mm2
Slab thickness – 150 mm
Zone factor – 0.1

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I f3

Importance factor – 1
Response reduction factor – 5
Rock and soil site factor (SS) – 1
Damping ratio – 5
Period in Z direction – 0.50 seconds

.

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= Importance factor depending upon the functional
use of the structures, characterized by hazardous
consequences of its failure, post-earthquake
functional needs, historical value, or economic
importance. Refer Table 6 of IS: 1893(Part 1)2002.

SS f4 = Rock or soil sites factor (=1 for hard soil, 2 for
medium soil, 3 for soft soil). Depending on type
of soil, average response acceleration coefficient
Sa/g is calculated corresponding to 5% damping.
Refer Clause 6.4.5 of IS: 1893 (Part 1) -2002.
ST f5 = Optional value for type of structure (=1 for RC
frame building, 2 for Steel frame building, 3 for
all other buildings). If this parameter is
mentioned the program will calculate natural
period as per Clause 7.6 of IS: 1893(Part 1)2002.

Figure – 1 Seismic zone of India as per geological map

3. ANALYTICAL METHODOLOGY
The analysis of structure is done by using STAAD PRO
software. The different configuration position of shear
wall in Reinforced Concrete building were analyzed for
stiffness and seismic stability with respect to the lateral
displacement in X and Z direction, drift at different storey
height level, buckling mode factor, node displacement data
and concrete and steel usage for economic and safe
construction of structure under seismic analysis.
The data used is as per Seismic definition (1983-2002)
provided which is static earthquake analysis method and
then applying soft storey check for deducting any soft
storey in building designed. The specification used by the
software is 1893-Specification = {RF f2, I f3, SS f4, (ST f5), DM f6,
(PX f7), (PZ f8), (DT f9)}
Where,
Zone f1 = Seismic zone coefficient. Refer to Table 2 of
IS:1893 (Part 1)-2002.
RF f2 = Response reduction factor. Refer Table 7 of IS:
1893 (Part 1) -2002.

© 2015, IRJET

DM f6= Damping ratio to obtain multiplying factor for
calculating Sa/g for different damping. If no
damping is specified 5% damping (default value
0.05) will be considered corresponding to which
multiplying factor is 1.0. Refer Table 3 of IS:
1893(Part 1)-2002.
PX f7 = Optional period of structure (in sec) in X direction.
If this is defined this value will be used to
calculate Sa/g for generation of seismic load
along X direction.
PZ f8 = Optional period of structure (in sec) in Z direction.
If this is defined this value will be used to
calculate Sa/g for generation of seismic load along
Z direction.
DT f9 = Depth of foundation below ground level. It should
be defined in current unit. If the depth of
foundation is 30 m or below, the value of Ah is
taken as half the value obtained. If the
foundation is placed between the ground level
and 30 m depth, this value is linearly
interpolated between Ah and 0.5Ah.
By default STAAD calculates natural periods of the
structure in both X and Z directions respectively which are
used in calculation for base shear. If, however, PX and PZ
are mentioned the program will consider these values for
calculation of average response acceleration coefficient. If
instead of PX and PZ values ST is mentioned the program
will calculate natural period depending upon the empirical
expression given in IS: 1893 (Part 1)-2002.

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Soft Storey Checking –

4. SOFT STOREY AND SHEAR WALL

As per the IS: 1893-2002 code Clause 7.1, to perform well
during an earthquake a building must have simple and
regular configuration, adequate lateral strength, stiffness
and ductility. This is because a building with simple
regular geometry and uniformly distributed mass and
stiffness in plan as well as in elevation, will suffer much
less damage than buildings with irregular configurations.

Shear wall is vertical structure member which can resist
moment, shear and axial load arising due to gravity and
lateral (earthquake) load. A soft storey is generally a weak
story which offers less stiffness or insufficient ductility to
the stresses generated due to earthquake. Soft stories are
generally encountered on the bottom stories of building
and hence failure at soft stories may result in failure of
whole structure. In such case providing shear wall is an
effective measure to counteract this problem. Shear walls
have appreciable stiffness in their own plane but offer
very little stiffness in a perpendicular plain.

Using the command PDELTA ANALYSIS instead of
PERFORM ANALYSIS. The PDELTA ANALYSIS will
accommodate all requirements of the second- order
analysis described by IS: 456, except for the effects of the
duration of the loads. PDELTA ANALYSIS, as performed by
STAAD may be used for the design of concrete members.
However it must be noted, to take advantage of this
analysis, all the combinations of loading must be provided
as primary load cases and not as load combinations.
This is due to the fact that load combinations are just
algebraic combinations of forces and moments, whereas a
primary load case is revised during the P-delta analysis
based on the deflections. Also it should be noted that the
proper factored loads (like 1.5 for dead load etc.) should
be provided by user. STAAD does not factor the loads
automatically.
The total requirement of concrete and steel bars is
calculated by the software as per IS-456, the node
displacement data provided in the form of table is
tabulated summary of maximum node displacement at
various locations of shear wall in the structure. By the
application of shear wall the lateral stability is checked
along with moment generated in the joint (nodes) of the
designed structure.



As per IS-1893:2002 (part I) [6]

A Soft Storey is one in which the lateral stiffness is less
than 70 percent of that in the storey above or less than 80
percent of the average lateral stiffness of the three storeys
above.
Due to high rise in population at a frequent rate
construction of apartment and high rise buildings is in
fashion to alter the land use to accommodate such huge
population. To further alter the land use and to make
construction economic parking and retail space is
provided at the ground floor of these structures and this is
where soft storey is encountered. Figure - 2 shows the
failure of whole structure due to soft storey at parking
level. Although no structural damage has been observed in
upper stories, but the structure looses it’s capacity to
resist gravity loads partially or fully making the structure
unusable as a whole.
Location of Shear Wall –
A shear wall is similar to column taking axial load but of
smaller thickness with respect to standard column as such
slab is to beam,
Shear wall has been also adopted as a member to bear
lateral forces due to various loading patterns specially to
counter lateral stress generated by seismic earthquake
forces.

Figure 2 – Failure of multi storey building due to soft
storey at parking level.

© 2015, IRJET

It has been studied and advised that building structure
provided with shear wall like member could easily bear
stress and enhance stiffness of the structure against the
drift of vertical structural alignment i.e. displacement of
column to beam or slab member forming a storey. The
structural location of shear wall should be such that it
allows maximum load to pass through it in lateral
direction for reducing shear failure to other structural
members such as column in normal direction, which may
fail in shear to lateral load induced by seismic waves.

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Table –2 Periphery frame displacement data as per
software calculations.

Figure – 3 Different position of Shear Wall, Side view.
Table -3 Core frame displacement data as per software
calculations.

Figure – 4 Different position of Shear Wall, Top view.

Table – 4 Intermediate frame displacement data as per
software calculations.

5. RESULT AND DISCUSSION
a)

Table for various mode of structures used.

Table -1 Bare frame displacement data as per software
calculations.

b) Graphical analysis based on software
evaluated result data

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Graph –1

Graph - 4

Graph –2

Graph - 5

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Graph – 3
Graph – 6

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6. CONCLUSION.

Figure – 4

On analysis based on designed structure with various
positional configuration of shear wall with respect to
seismic load acting as calculated from STAAD.Pro
software shows that, Intermediate position of shear wall is
best suited with respect to core and periphery positions of
the structure.
The lateral displacement in X- direction and Z- direction is
restricted more by the intermediately configured shear
wall making building structure safe to shear failure.
The Proportionate material requirement for the
restriction of applied load safely; in the construction of
building also shows the Intermediate configuration will be
more economical than other with exception of steel in core
and concrete in periphery position; but this could not
retard structural buckling considerably.
The shear wall make the structure safe by enhancing
stiffness, ductility and reducing lateral and vertical drift of
the storey at joints, which is due to direct reduction of
displacement of member along the propagation of seismic
force.

Figure - 5

In Bare frame structure soft storey is found to be acting at
base and at 9th storey whereas there was drift in structure
(The storey drift exceeds 0.004 times the storey height for
1893 load case - 1 applied) after configuration of shear
wall to structure both soft storey and drift exit due to
resistive layer of shear wall body attached to structure
assembled as additional column to retard the
displacement and counter shear failure.

6. REFERENCES
[1]

[2]

[3]

Figure – 6
© 2015, IRJET

IS: 1893(part 1) : 2002, “ Criteria for earthquake
resistant design of structures, part 1, general
provisions and buildings “, Fifth revision, Bureau
of Indian Standerds, Manak Bhavan, Bahadur Shah
Zafar Marg, New Delhi 110002.
“Review on Shear wall for soft storey high rise
building, Misam Abidi and Mangulkar Madhuri N.
,International Journal of Civil and Advance
Technology, ISSN 2249-8958,Volume-1,Issue-6,
August 2012
“A comparative study of omrf & smrf structural
system for tall & high rise buildings subjected to
seismic load”, Volume: 02 Issue: 09 | Sep-2013 by
G.V.S.Siva Prasad and S.Adiseshu.

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[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

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“Effect of change in shear wall location on
storey drift of multi-storey residential
building subjected to lateral load”, Ashish S.
Agrawal and S. D. Charkha, International
journal of Engineering Research and
Applications, Volume 2, Issue 3,may-june
2012, pp.1786-1793.
“Configuration of multi-storey building
subjected to lateral forces”, M Ashraf, Z. A.
Siddiqui, M. A. Javed, Asian journal of civil
engineering ,vol. 9,no.5, pp. 525-535, 2008.
Solution of shear wall in multi-storey
building”, Anshuman, Dipendu Bhunia,
Bhavin Ramjiyani, International journal of
civil and structural engineering, Volume 2,
no.2, 2011.
IS: 875 (Part 2) – 1987 (Reaffirmed 2008),
“Code of practice for design loads for
buildings and structures. Part 2- Imposed
load”.
Shrikhande Manish, Agrawal Pankaj (2010).
”Earthquake Resistant Design of Structures.”
PHI Learning Private Limited New Delhi.
Jaswant N. Arlekar, Sudhir K. Jain and C.V.R.
Murty. Seismic response of RC frames
buildings with soft first story’s. Proceedings
of the CBRI Golden Jubilee Conference on
Natural Hazards in Urban Habitat, 1997, New
Delhi.
Wakchaure MR, Ped SP. Earthquake Analysis
of High Rise Building with and Without
Infilled Walls. International Journal of
Engineering and Innovative Technology.
2012; volume 2; 89-94.
M. Asharaf, Z. A. Siddiqi, M. A. Javed,
“Configuration of Multi-storey building
subjected to lateral forces”. Asian Journal of
Civil Engineering (Building & Housing), Vol.
9, No. 5 Pages 525-537.
H.-S. Kim, D.-G. Lee“Analysis of shear wall
with openings using super elements”
Engineering Structures 25 (2003) 981–991
[13]. M. Shariq, H. Abbas, H. Irtaza, M.
Qamaruddin “Influence of openings on
seismic performance of masonry building
walls” Building and Environment 43 (2008)
1232–1240

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