M.tech project on seismic activity

1. UNDER THE GUIDANCE
Mr.T.Ram Prasanna Reddy Kumar
(Assistant Professor)
Submitted by:-
K.SAGAR
18E11D2008

2. Contents:
 Abstract
 Intoduction
 Literature review
 About E-Tabs
 Response Spectrum Method In Detail
 Model Dimensions and Analysis
 Results and Discussion
 Conclusion
 Reference from different journals

3. ABSTRACT
 A multistorey building with open ground storey placed in
Hyderabad(seismic zone-II) is thought about for this study.
 This building is analyzed for two diiferent cases by response
spectrum analysis method
(a) Considering infill strength and stiffness(OGS).
(b) Not considering infill strength and stiffness(Bare frame).
 Infill stiffness was created in ETABS by using Equivalent
Diagonal strut approach .
 ETABS software is used for structural modeling and Response
spectrum analysis. Analysis is carried out for these models and
results were compared.

4. INTRODUCTION
 NEED FOR INVESTIGATIONS
This concept provides a new approach for establishing
design.objectives and desired performance levels for new and existing
building. Seismic deficient buildings are being upgraded using
performance based design.
Such building, when subjected to severe ground motion, might suffer
extensive damage or even collapse. The recent advent of performance
based design has brought the -linear Dynamic Analysis procedure to
the forefront.
Analysis of structures using finite elements packages is an
alternate approach to predict the behaviour of a structure. In the
present study, Response spectrum is adopted to analyse the seismic
behaviour of Multi storey building using finite element package ETABS
2016.

5. OPEN GROUND STOREY BUILDING
 Open ground storey(OGS) buildings are commonly constructed on
populated countries like india ,since they provide much need parking
space in an urban environment.
 Failures observed in past earthquakes show that the collapse of such
buildings is predominantly due to the formation of soft-storey
mechanism in the ground storey coulmns.In conventional design
practice , the contribution of stiffness of infill wall presents in upper
storey of OGS framed buildings are ignored in structural modeling.
 From the past earthquakes it was evident that the major type of failure
that ocuured in OGS buildings included snapping of lateral ties,
crushinng of core concrete bukling of longitudinal bars etc

6. TYPICAL MASNORY INFILLED BUILDINGS
 Typical masnory infilled frames contains infill walls through out
the building in all storey uniformly.
 Although the infill walls are known to provide the stiffness and
strength to the building globally, these are considered as non
structural by design codes and are commonly ignored in the
design practice for the more convenience.
 The presence of infill walls in a framed building not only
enhance lateral stiffness in the building but also the alter the the
transmission of forces in beams and coulmn as compared to bare
frame.

8. OBJECTIVES OF THESIS
(a) To study the behavior of Open Ground Stroey buildings designed considering
the magnification factor (M.F) suggested by Is codes.
(b) To study the Performance and behavior of the typical OGS buildings using
Response spectrum Analysis
(c) To study the effect of infill strength and stiffness in the seismic analysisod
OGS.
(d) To check the applicability of the muliplication factor of 2.5 as given in the
indian standard Is 1893-2002 for design of multi storey framed building. (e)
(e) To assess the effect of varying the infill arrangements on the analysis result by
taking various combinations of infill thickness strength, modulus of elasticity
and openings.
(f) To compare the results of different zones.

9. SCOPE OF THE STUDY
 Open Ground Storey buildings have been most common now a days
and are constructed heavily in high populated countries like india,
since they provide much needed parking space in an urban
environment.
 Failures observed in past earthquakes proved that the collapse in such
buildings is predominently due to the formation of soft-storey
mechanism in the coulmns of the ground storey building.
(a) RC Framed buildings, which is irregular in plan
(b) Multi storey framed buildings with no basement and no shearwall
(c) Infill walls non-integrated with Rc frames
(d) Concept of out of plane action of masnory not taken into account

10. LITERATURE REVIEW
SL Authors Title of the paper Description
1. R.Suresh 2017 Seismic analysis of
medium rise open
ground storey
framed building by
Response spectrum
method analysis
Considers higher
modes effects as
well as the
progressive
changes in the
dynamic structure
2. Abhisheik shanker
2018
Analysis of multi
storey building with
and without infill
walls by stimulation
tools
For linear
Dumamic
problems
.Introduced
influence matrix

11. SL Authors Title of the Paper Description
3. Bhumik R.Gajjar
Dr.k.b.parikh
2017
Seismic analysis of
low rise open ground
storey framed
building
Structures showing
the great significance
of high mode effect
on seismically
induced forces of tall
building
4. N.sivakumar
S.karthick
2013
Seismic vulnerability
of open ground floor
columns in multi
story building
Shear wall location
to a multi storey
building based on its
both elastic and
elasto plastic
behaviour
5. Deepak
Mr.vaibhav gupta
2016
Seismic analysis of
high rise open
ground storey
framed building
Seismic response is
evaluated by Time
history method and
compared with non
linear static analysis
for high accuracy

12. ABOUT E-TABS SOFTWARE
 Extended Three Dimensional Analysis of Building System
 Used for structural analysis of any structure or building
 E Tabs software given by Ashraf Habibullah
 Modeling can be done with various codes with accurate
results
 E Tabs and Sap 2000 are similar but sap is for individual
frame analysis and design

13.  ETABS is a sophisticated, yet easy to use, special purpose analysis
and design program developed specifically for building systems.
 ETABS 2016 features an intuitive and powerful graphical interface
coupled with unmatched modelling, analytical, design, and
detailing procedures, all integrated using a common database.
 Although quick and easy for simple structures, ETABS can also
handle the largest and most complex building models, including a
wide range of linear and nonlinear behaviours, making it the tool
of choice for structural engineers in the building industry.

14. Computations made with in E-tabs
1.Multi-story commercial, government and health care
facilities Parking garages with circular and linear ramps.
2. Buildings with curved beams, walls and floor edge.
3. Buildings with steel, concrete, composite or joist floor
framing Projects with multiple towers.
4. Complex shear walls and cores with arbitrary openings.
5. Buildings based on multiple rectangular and/or cylindrical
grid systems Flat and waffle slab concrete buildings

15. 6. Buildings subjected to any number of vertical and lateral load
cases and combinations, including automated wind and seismic
loads.
7. Multiple response spectrum load cases, with built-in input
curvesAutomated transfer of vertical loads on floors to beams
and walls .
8. Capacity check of beam-to-column and beam-to-beam steel
connections PDeltaanalysis with static or dynamic analysis.
9. Explicit panel-zone deformations
10. Construction sequence loading analysis and etc..

16. RESPONSE SPECTRUM METHOD
 Response spectra are curves plotted between maximum response of
SDOF system subjected to specified earthquake ground motion and its
time period (or frequency).
 Response spectrum can be interpreted as the locus of maximum response
of a SDOF system for given damping ratio.
 Response spectra thus helps in obtaining the peak structural responses
under linear range, which can be used for obtaining lateral forces
developed in structure due to earthquake thus facilitates in earthquake-
resistant design of structures.

17. Factor Influencing Response Spectra
 The response spectral values depends upon the
following parameters,
1. Energy release mechanism
2. Epicentral distance
3. Focal depth
4. Soil condition
5. Richter magnitude
6. Damping in the system
7. Time period of the system

18. Error in response spectra due
discretization.

19. Displacement reaction spectra of El – Centro, 1940 tremor ground movement.

20. RESPONSE SPECTRUM METHOD (DYNAMIC ANALYSIS)

21. Model Dimensions and Analysis

22. LOADS AND STRUCTURAL DIMENSIONS OF BUILDING

23. Plan Of Model

24. Structural dimensions of G +10storey building

25. Geometry of the building without infill wall at ground storey

26. Geometry of the building with infillwall at ground storey

27. Earthquake Load cases for the structure

28. Response spectrum Load case data

29. ZONE II WITH AND WITH OUT INFILL WALLS:-

30. Story Stiffness

31. Story Shear

32. Story Drifts

33. StoryOverturning moment

34. BM and SF Diagram for beam

35. BM and SF Diagram for column

36. RESULTS AND DISCUSSIONS
Storey number Zone II Base
Shear
Zone III Base
Shear
Zone IV Base
Shear
Remarks
10 19320 16790 25300 Maximum @top
9 17388 15111 22770
8 15456 13432 20240
7 13524 11753 17170
6 11592 10074 15180
5 9660 8395 12650
4 7728 6716 10120
3 5796 5037 7590
2 3864 3358 5060
1 1932 1679 2530
0 0 0 0 Minimum @
bottom

37. Comparison of Base - Shear for with &without of infill wall for OGS:
Model(G+10)
Storey
With out infill wal
Zone II Zone III Zone IV
Multiplication
factor
Base shear X - axis 1932.05 1679.15 2530 1.15,1.50 and
1.30
Y - axis 1790 1470 2239 1.21,1.52 and
1.25
Model(G+10)
Storey
With infill wall
Zone II Zone III Zone IV
Multiplication
factor
Base shear X - axis 2375 2232 2780 1.06,1.24 and
1.17
Y - axis 2372 2158 2371 1.09,1.09 and
1.0

38. RSA Result for (G+10) Building Model with out infill
Model Zone II Zone III Zone IV M.F
Column(G.S) Max B.M 169691.99 137025.26 205631.36 1.23,1.50
and1.21
Beam(G.S) Max B.M 420282.26 182310.30 228569.39 2.30,1.25 and
1.83
RSA Result for (G+10) Building Model with infill
Model Zone II Zone III Zone IV M.F
Column(G.S) Max B.M 92892.43 79811.38 121428.4 1.16,1.53
and1.30
Beam(G.S) Max B.M 83245.25 71522.58 108876.20 1.16,1.52 and
1.30

39. CONCLUSIONS
 Linear (Static/Dynamic) investigation shows that section powers at the
ground story increments for the area of in will dividers at the upper
stories. Yet, plan power M.F discovered to be considerably less than 2.5.
 Seismic examination of without infill dividers at the ground story and
with infill at the ground story prompts under assessment of base shear.
 Under assessment of base shear drives the shaking of structure
during eaarth tremor it is just for with out infill divider at the ground
story where as the infill gives solidarity to the structures that is
firmness quality and story shear.Therefore it is essential to consider the
infill dividers in seismic investigation of structures.

40.  Response range results shows by previously mentioned focuses we infer
that M.F needed for (G+10) Story Model with infill divider at the
ground story is for bars and segments Mf range (1.16-1.52-1.3)it shows
that for Zone II is beneath 53.6% which is recommended by IS code
i.e2.5. Also for Zone III and Zone IV is beneath 39.2% and 48%.
 We additionally reason that the base shear is more for infill divider set
at the ground story contrast with out infill at the ground story, Which
is one potential method of disappointment in OGS.

41.  The M.F needed for (G+10) Story Model without infill divider at the
ground story is, Beams M.F ranges (2.3-1.12-1.83) it shows that for Zone
II is under 8% which is recommended by is code i.e.2.5. Essentially for
Zone III and Zone IV it is than 55.2% and 26.8%. For Columns the M.F
goes from (1.23-1.5-1.21) it shows that for Zone II it is under 50.8% which
is recommended by is code that is 2.5. likewise for Zone III and Zone IV
is under 40% and 51.6%.
 The graph shows the worldwide firmness and versatile BS prerequisite
of OGS structures changes impressively when infill divider is
overlooked