STRUCTURAL SYSTEM ANALYSIS AND DESIGN FOR
SAFE HOUSE
Mohammad Rezaeianpakizeh
A project report submitted in partial fulfillment of the
Requirements for the award of the degree of
Master of Engineering (Civil-Structure)
Faculty of Civil Engineering
Universiti Teknologi Malaysia
JULY 2012
iii
Dedicated to my beloved mother and devoted father.
Words cannot describe how much they mean to me.
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ACKNOWLEDGEMENT
The realization of this research was only possible due to the several people's
collaboration, to which desire to express my gratefulness.
I would like to thank in a special way to Assoc. Prof. Dr. Abdul Kadir
Marsono, my supervisor, I am grateful for the trust deposited in my work and for the
motivation demonstrated along this research. His support was without a doubt crucial
in my dedication this investigation. He has been the ideal thesis supervisor. Without
his inspirational instruction and guidance I was not able to complete this project. His
sage advice, insightful criticisms, and patient encouragement aided the writing of this
thesis in innumerable ways.
Appreciation is extended to all laboratory staff for advices and suggestions of
the work, and for the friendship that always demonstrated along these months of this
project.
I would also like to express my gratitude to all my friends especially,
Hamidreza Khoshnoud for his extended support. With his help, it was possible for
me to complete this project.
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ABSTRACT
The observation of post-earthquakes damages on reinforced concrete buildings has
clearly shown that the presence of nonstructural elements, such as infill walls, may
significantly affect the seismic performance of buildings. The study describes the
analysis and design, the engineering process the new type of safe room according to
the FEMA guidance. It also evaluates the effects of in-fill frames and the linear
response of reinforced concrete braced frames and comparison with frames with
shear wall. The main conclusion drawn from this study is to elaborate that the
masonry in-fills, are strongly influence the structural seismic response and contribute
to the overall stiffness and can decrease drifts and displacements. Infill walls have
significant role in the strength and ductility of RC framed structures and should be
considered in both analysis and design globally. These walls make the structure
significantly stiffer, and reduce the natural period of the structure. Locally, infill
walls changed the load path, the distribution of forces between different elements of
the structure, and the demand forces on their adjacent elements of the bounding
frame. Due to the high relative stiffness of the infill frames, they act as the main
lateral load-resisting system and attract larger portions of the earthquake-induced
inertia forces.
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ABSTRACT
Pemerhatian selepas gempa bumi yang menaberi kerosakan ke atas bangunan
konkrit bertetulang telah jelas menunjukkan bahawa kehadiran unsur bukan struktur
seperti dinding pengisian, boleh memberi kesan kepada prestasi seismik bangunan.
Kajian ini menerangkan analisis dan reka bentuk, proses kejuruteraan jenis baru
“safe room” mengikut kepada petunjuk FEMA dan menilai kesan kerongka pengisi
dan tindak balas linear kerangka berembat konkrit bertetulang dan dengan kerangka
dinding ricih. Kesimpulan utama yang diperolehi daripada kajian ini adalah untuk
menjelaskan bahawa bato dalam-mengisi. Kuat mempengaruhi tindak balas seismik
struktur dan menyumbang kepada kekukuhan keseluruhan dan boleh mengurangkan
sesaran dan anjakan. Dinding pengisian mempunyai peranan penting dalam kekuatan
dan kemuluran struktur kerangka RC dan perlu dipertimbangkan dalam analisis dan
reka bentuk global. Dinding ini membuat struktur ketara yang lebih kuat,
mengurangkan tempoh gegaran semulajadi struktur. Dinding pengisian mengubah
laluan beban, dan mengagihkan daya di antara elemen-elemen struktur yang berbeza,
dan berkuasa memindahkan beban ke bersebelahan. Disebabkan oleh kekukuhan
tinggi berbanding dengan kerang ka pengisian, mereka bertindak sebagai sistem sisi
utama menentang beban dan menarik bahagian yang lebih besar daya inersia.
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TABLE OF CONTENTS
CHAPTER TITLE PAGE
TITLE vi
DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
ABSTRAK vi
LIST OF CONTENT vii
LIST OF TABLE x
LIST OF FIGURES xi
LIST OF SYMBOLS xiii
CHAPTER 1 INTRODUCTION
1.1 Introduction .................................................................. 1
1.2 problem statement ....................................................... 2
1.3 Objective of study ........................................................ 3
1.4 Scope of study .............................................................. 4
1.5 Significant of study ...................................................... 5
CHAPTER 2 Literature review
2.1 FEMA 320.................................................................... 7
2.2 FEMA 361.................................................................... 8
2.3 FEMA 431.................................................................... 9
2.4 Characteristics of Tornadoes ....................................... 10
2.5.Shear Wall ................................................................... 11
2.6 Bracing ........................................................................ 12
2.61 Concrete Brace .......................................................... 13
2.7 Effect of infill walls on reinforced concrete frame ..... 15
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2.8 Behavior of infilled frames ......................................... 21
2.9 Reinforced Concrete Frames with Masonry Infill ...... 24
2.10 Seismic Behaviour of RC Frames
with masonry wall ..................................................... 25
CHAPTER 3 METHODOLOGY
3.1 Introduction .................................................................. 30
3.2 ETABS Software.......................................................... 36
3.3 Load Combinations Using
Allowable Stress Design .............................................. 37
3.4 Tornado Community Safe Room
Design Criteria ............................................................. 38
3.5 Wind Design Parameters for Tornado
Community Safe Rooms .............................................. 39
3.5.1 Wind Pressure (Y- Direction) ............................. 41
3.5.2 Wind Pressure (X- Direction) ............................. 42
3.6 Seismic analysis ........................................................... 43
3.7 Static analysis ............................................................... 43
3.7.1 Storey1 (I-S model) ............................................. 44
3.7.2 Storey2 ................................................................ 45
3.7.3 Storey3 ................................................................ 45
3.7.4 Steel elements ..................................................... 46
3.7.5 Concrete element................................................. 46
3.7.6 Concrete Beam ................................................... 47
3.8 Response spectrum ....................................................... 48
3.9 Time History ................................................................ 50
3.9.1 ELCENTRO Earthquake ........................................... 50
CHAPTER 4 Findings and Results
4.1 Finding and Results ...................................................... 53
4.2 Models I-S and B-S ...................................................... 57
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4.3 Model I-B and B-B ...................................................... 59
4.4 Models B-S and B-B .................................................... 60
CHAPTER 5 Discussion of Result ........................................................... 62
CHAPTER 6 Conclusion and Recommendation..................................... 63
REFERENCES ................................................................................................... 65
APPENDIX ......................................................................................................... 70
x
LIST OF TABLES
TABLE TITLE PAGE
4.1 Base shear and weight of the models 53
4.2 Maximum Displacements 54
4.3 Maximum Drifts 55
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LIST OF FIGUERS
FIGURE TITLE PAGE
1.1 Plane Of Building with Safe House 4
1.3 Safe House With Shear Wall 5
1.3 Example of Failure 6
2.1 Desai simple triangular modelling in different loading
stages
14
3.1 Models of study 31
3.2 I-S Model 32
3.3 B-S Model 33
3.4 I-B Model 33
3.5 B-B Model 34
3.6 Flow chart of this research 35
3.7 Tornado Safe Room Design Wind Map 39
3.8 GPF Y-Direction 41
3.9 GPF Y-Directions 42
3.10 Response Spectrum Record 48
3.11 ELCENTRO Acceleration 51
3.12 ELCENTRO Record 51
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3.13 Scaled ELCENTRO Record 52
4.1 CM Drift in Bare frame with shear wall 56
4.2 CM Drift in in-fill frame with shear wall 56
4.3 CM Drift in Bare frame with Brace 56
4.4 CM Drift in In-fill frame with Brace 57
4.5 Maximum story drift in I-S and B-S models 57
4.6 Maximum story displacements in I-S and B-S models. 58
4.7 Maximum acceleration of each story in I-S and B-S
models
58
4.8 Maximum story drift in I-B and B-B models. 59
4.9 Maximum story displacements in I-S and B-S models 59
4.10 Maximum acceleration of each story in I-S and B-S
models.
60
4.11 Maximum story drift in B-S and B-S models. 60
4.12 Maximum story displacements in B-B and B-S models 61
4.13 Maximum acceleration of each story in B-B and B-S
models
61
xiii
TABLE OF SYMBOLS
G = gust effect factor for MWFRSs of flexible buildings and other structures
GCp,, = combined net pressure coefficient for a parapet
GCp =product of external pressure coefficient and gusteffect factor to be used in
determination of wind loads for buildings
GCpj = product of the equivalent external pressure coefficient and gust-effect factor
to be used in determination of wind loads for MWFRS of low-ris buildings
GCpi = product of internal pressure coefficient and gusteffect factor to be used in
determination of wind loads for buildings
q = velocity pressure, in lb/ft2 (IV/m2)
qj, = velocity pressure evaluated at height z = h, in lb/ft2 (IV/m2)
q; = velocity pressure for internal pressure determination, in lb/ft2 (IV/m2)
qp =velocity pressure at top of parapet, in lb/ft2 (IV/m2)
q, =velocity pressure evaluated at height z above ground, in lb/ft2 (IV/m2)
R = resonant response factor
Ss = mapped MCE, 5 percent damped, spectral response acceleration parameter at
short periods
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S1 = mapped MCE, 5 percent damped, spectral response acceleration parameter at a
period of 1 s
SaM = the site-specific MCE spectral response acceleration at any period
SDs = design, 5 percent damped, spectral response acceleration parameter at short
periods
SMs = the MCE, 5 percent damped, spectral response acceleration at short periods
adjusted
for site class effects
SMl = the MCE, 5 percent damped, spectral response acceleration at a period of 1 s
adjusted for site class effects
T = the fundamental period of the building
T, = approximate fundamental period of the building
TL = long-period transition period
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CHAPTER 1
INTRODUCTION
1.1 Introduction
Buildings in any geographic location are subject to a wide variety of natural
phenomena such as windstorms, floods, earthquakes, and other hazards. While the
occurrence of these incidents cannot be precisely predicted, their impacts are well
understood and may be can able to be managed effectively through a comprehensive
program of hazard mitigation planning.
Every year earthquakes, tornadoes and other extreme windstorm cause
fatalities or even kill people, devastate and millions of dollars’ worth property.
The likelihood that a tornado will strike building is a matter of probability. Tornado
damage to building is predictable at certain accuracy. Administrator of school and
other public buildings should have a risk analysis performed to determine the
likelihood that a natural disaster will occur and look at the potential severity of the
event. If a building determined to be at risk, the safest part of the building may offer
the protection if a natural disaster strikes. From the local perspectives a tornado is
the most destructive of all atmospheric phenomena. The wind speed generated by
some tornadoes is so great such that designing for these extreme winds is
unaffordable and beyond the scope of building codes and engineering standard.
Most buildings that have received engineering attention, such as schools, and
that are built in accordance with sound construction practices can usually withstand
wind speeds but may provide sufficient resistance to tornadic wind only if the
2
building is located on the outer edge of the tornado vortex. In addition if a portion of
the building is built to a higher tornado design standard, then both building and
occupant survival ability are improved.
It is an important measure for the international society establishing the
emergency shelter to deal with the emergent events and victims. And also, the
emergency shelter is the temporary living place for people in modern big cities to
avoid the danger of natural disasters, such as the earthquake, fire, explosion, flood,
and so on. Based on scientific planning and standard management, the emergency
shelter could be used to supply the basic subsistence requirements for people in
dangers. Actually, the planning construction of the emergency shelter in cities is a
kind of systems project, which included all kinds of inspects in society.
Shear walls, and braced frames, have been an effective and valuable method
to enhance structures against lateral loads. In wind or seismic excitations, inclined
elements react as truss web elements which would bear compression or tension
stresses.
1.2 Problem statement
When the extreme hazard events occur almost every things will be destroy
and cause devastation and fatalities. The structure will be damaged from various
aspects of structural engineering. Well-constructed houses destroy and some
structure lift from foundation, roofs and some walls torn from structure and extensive
damage will be to non-structural elements such as, windows, doors and some curtain
walls. Some buildings have shelter or small safe-room, but there are not available or
accessible during event. The orders to study the effects of natural disaster, the nature
of extreme earthquake and flood have to be understood in structural engineering
point of view.
The observation of post-earthquakes damages on reinforced concrete
buildings has clearly shown that the presence of nonstructural elements, such as infill
3
walls, may significantly affect the seismic performance of buildings, both in terms of
seismic demand and capacity. The experience developed about the seismic
assessment of existing buildings has definitely demonstrated that infill masonry walls
often behave like real primary elements, and anyway have a significant role in the
structural response recently, the influence of infill walls on the seismic structural
response of RC buildings has been widely investigated by many research
experimental and numerical studies.
Low tensile strength of concrete material and moulding made it a challenge to
use in inclined members. In practice, there have been various methods to consider
this defect such as disengagement of brace elements in tension or utilization of pre-
stressed braces.
1.3 Objectives of study
The specific objectives of this study are as follows:
- To describe in the form of analysis and design, the engineering process of
the new type of shelter or safe room embedded inside the main building.
- To evaluate of linear response of reinforced concrete frames, braced frames
and comparison with frames with shear wall.
- To investigate the stiffness of infills in frames of building and evaluate the
interstory drift for lateral loads.
4
1.4 Scope of study
The purpose of this research is to study the linear response of the new type of
shelter or safe room that surrounded by reinforced concrete frames which contain
reinforced concrete braces or shear wall as the major structural elements against
lateral loads.
This study focuses on evaluation of displacement and inter-story drift of
reinforced concrete braced frames for earthquake and compare with frames with
shear wall in two cases, infill frame and non-infill frame.
Figure 1.1 Plan of building with safe house
5
Figure 1.2 Perspective view of safe house by shear wall
1.5 Significant of study
A reliable assessment of the seismic response of existing RC framed
buildings should include an accurate model of the infill panels. In this research, the
numerical analysis is carried out to evaluate the effect of stiffness of the infill walls
on the behavior of structures subjected to lateral loads. It is observed that the
presence of correctly distributed infill elements can mitigate horizontal
displacements and increase the overall resistance to horizontal actions. In general, a
significant increase in the stiffness of the system could be induced, with a consequent
decrease of the natural vibration periods of the building.
6
Figure 1.3 (a) typical column failure in the first story. Infill wall contributed
to lateral stiffness and short column effects around windows. (b), (c): soft
storey mechanism at the first level in a RC building
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6.1 REFERENCES
1. Desai JP, Jain AK, Arya AS, Seismic response of R.C. braced frames, Computers
and Structures, No. 4, 29[1988]557-68.
2. Iskhakov I, Self-Variable Stiffness System for Optimal Seismic Response of RC
Frame with Concrete Braces, Earthquake Resistant Engineering Structures
III, [2001]
3. Xu S, Niu D, Seismic behavior of reinforced concrete braced frame, ACI
Structural Journal, No. 1, 100(2003)120-25.
4. Watanabe, Development of the "Self-Installing PCa Brace Method" for Seismic
Reinforcement of Building Walls, October 2002.
5. Khaloo∗ and M. Mahdi Mohseni, NONLINEAR SEISMIC BEHAVIOR OF RC
FRAMES WITH RC BRACES.A.R. Department of Civil Engineering, Sharif
University of Technology, Azadi Avenue P.O. Box: 11365-9313, Tehran,
Iran [2004]
6. Bayındırlık ve _skan Bakanlıgı, “Afet Bölgelerinde Yapılacak Yapılar Hakkında
Yönetmelik” (ABYYHY-98), Türkiye Hazır Beton Birligi, [1999].
7. Sucuoglu, H. and McNiven, H. D. “Seismic Shear Capacity of Reinforced
Masonry Piers”, Journal of Structural Engineering, Vol. 117, No. 7, pp. 2166-
2187, July [1991].
8. Sucuoglu, H. and Erberik, A., “Performance Evaluation of a Three-Storey
Unreinforced Masonry Building During the 1992 Erzincan Earthquake,
Earthquake Engineering and Structural Dynamics, Vol. 26, [1997].
9. Paulay, T. and Priestley, M. J. N, Seismic Design of Reinforced Concrete and
Masonry Buildings”, John Wiley & Sons, Inc, [1992].
10. Smith, B. S. and Coull, A., “Tall Building Structures: Analysis and Design”, John
Wiley & Sons, Inc., [1991].
83
11. Smith, B.S. and Carter, C., “A Method of Analysis for Infilled Frames”,Proc.
ICE, Vol. 44, pp.31-48, September [1969].
12. Applied Technology Council, “NEHRP Guidelines for the Seismic Rehabilitation
of Buildings” (ATC 33), Federal Emergency Management Agency Report
FEMA 273, Washington [1997].
13. Roko Zarinic, Design Loads for Building, Turkish Standards Institute, Ankara,
November [1997].
14. Gülkan, P. and Sözen, M.A., “Procedure for Determining Seismic Vulnerability
of Building Structures”, ACI Structural Journal, Vol. 96, No.3, pp. 336-342,
[1999].
15. Ersoy, U. and Marjani, F., “ Behavior of Brick Infilled Reinforced Concrete
Frames Under Reversed Cyclic Loading”, ECAS 2002 Internatiol
Symposium on Structural and Earthquake Engineering Symposium
Proceedings, pp. 142-150, October [2002].
16. Demir, F. and Sivri, M., “Earthquake Response of Masonry Infılled, July 2003
17. Pujol S, Fick D. The test of a full-scale three-story RC structure with masonry
infill walls, Engineering Structures 32[2010].
18. Mónica Puglisi, Maylett Uzcategui, Modeling of masonry of infilled frames, Part
I: The plastic concentrator, Engineering Structures 31[2009]113-8.
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