An-Najah National University 

Faculty of Graduate Studies 

 

 

 

 

Enhancing Earthquake Resistance of 

Local Structures by Reducing 

Superimposed Dead Load 

 

By 

Hasan J. Alnajajra 
 

Supervisor 

Dr. Abdul Razzaq A. Touqan 

 

Co-Supervisor 

Dr. Monther B. Dwaikat 

 
This Thesis is Submitted in Partial Fulfillment of the Requirements for 

the Degree of Master of Structural Engineering, Faculty of Graduate 

Studies, at An-Najah National University, Nablus, Palestine. 

2018



II 

 

 

 

 

 

 
Enhancing Earthquake Resistance of Local Structures by 

Reducing Superimposed Dead Load 

 

By 

Hasan J. Alnajajra 

 

This thesis was defended successfully on 8/2/2018 and approved by: 

Defense Committee Members  Signature 

 Dr. Abdul Razzaq A. Touqan / Supervisor …………..…… 

 Dr. Monther B. Dwaikat / Co-Supervisor 
…………..…… 

 Dr. Maher A. Amro / External Examiner 
…………..…… 

 Dr. Riyad A. Awad / Internal Examiner 
…………..…… 



III 

DEDICATION 

To our first and only perfect teacher who had laid out the groundwork for the 

spiritual education of mankind our prophet Mohammed Peace be upon him. 

To the one who didn’t just give me birth, he gave me a good life. He didn’t 

just provide me education, he gave me good life experience. It is men like 

him, who become loving and glorious fathers. 

To the one who always being there for me to love me and care for me when 

I felt like no one else did. No one can ever take your place ever.  

To my second mother who stood strong beside me when my whole world 

was darker and made it full of brightness. The one who granted me the true 

love and happiness. You did not allow me to give up but inspired me to insist 

on success. My darling wife. 

To the gift of Allah and the sight of our eyes who represent the continuity of 

our life. My lovely kids “Tameem, Sham, and Waseem”.  

To those who were the gift of my father and mother, my brothers and sisters, 

particularly my brother “Abedelkareem”. 

To my father and mother in law and all other relatives who wish me all 

success in life. 

 

I present this thesis. 



IV 

ACKNOWLEDGMENT 

While my first gratitude appreciation must be directed to my creator ……. 

Allah (SWT).  

I will never forget to express my great appreciation to my teachers for their 

generous support which they offered to me along through the whole period 

of my study.  

My special gratitude appreciation is directed towards my supervisors:  

 Dr. Abdul Razzaq A. Touqan. 

 Dr. Monther B. Dwaikat. 

To all the teaching staff teachers and supervisors.  

To the great center of science; An-Najah National University.  

My special appreciation to Dr. Haitham Ayyad, Dr. Mohammad Manasrah, 

and Mr. Mohammad Abuhamdieh. 

Besides, everyone who contributed in completing this research. 

 

 

 

 

 

 

 

 



V 

 اإلقرار

 أنا الموقع أدناه مقدم الرسالة التي تحمل عنوان

Enhancing Earthquake Resistance of Local Structures 

by Reducing Superimposed Dead Load 

ليه حيثما إارة أقر بأن ما اشتملت عليه هذه الرسالة إنما هو نتاج جهدي الخاص، باستثناء ما تمت اإلش

حث علمي أو ورد، وأن هذه الرسالة ككل، أو أي جزء منها لم يقدم من قبل لنيل أية درجة علمية أو ب

 بحثي لدى أية مؤسسة تعليمية أو بحثية أخرى.

DECLARATION 

The work provided in this thesis, unless otherwise referenced, is the 

researcher's own work, and has not been submitted elsewhere for any 

other degree or qualification. 

 

Student’s Name اسم الطالب: 

Signature التوقيع:  

Date التاريخ: 

 



VI 

TABLE OF CONTENTS 
 

DEDICATION ............................................................................................ III 

ACKNOWLEDGMENT ............................................................................. IV 

DECLARATION ......................................................................................... V 

TABLE OF CONTENTS ............................................................................ VI 

LIST OF FIGURES ................................................................................... XII 

LIST OF TABLES .................................................................................... XV 

LIST OF ABBREVIATIONS ............................................................... XVIII 

LIST OF SYMBOLS ................................................................................ XX 

ABSTRACT ....................................................................................... XXVIII 

CHAPTER 1 .................................................................................................. 1 

INTRODUCTION ......................................................................................... 1 

1.1 General ................................................................................................. 2 

1.2 Problem Statement ............................................................................... 3 

1.3 Research Questions .............................................................................. 7 

1.4 Research Objectives ............................................................................. 8 

1.4.1 Research Overall Objective ........................................................... 8 

1.4.2 Research Sub-objectives ................................................................ 8 

1.5 Research Scope and Limitations .......................................................... 8 

1.6 Structure of the Thesis ......................................................................... 9 

CHAPTER 2 ................................................................................................ 12 

LITERATURE REVIEW ............................................................................ 12 

2.1 Introduction ........................................................................................ 13 

2.2 Earthquakes Phenomena .................................................................... 14 

2.2.1 Causes of Earthquakes ................................................................. 14 

2.2.2 Theory of Plate Tectonics ............................................................ 14 

2.3 Seismicity of Palestine ....................................................................... 16 

2.3.1 Earthquake Sources in Palestine .................................................. 16 



VII 

2.3.2 Historical Overview for the Dead Sea Earthquakes .................... 18 

2.4 Earthquake Resistant Buildings ......................................................... 20 

2.5 Lateral-Force Resisting Systems........................................................ 20 

2.5.1 Structural Diaphragms ................................................................. 21 

2.5.2 RC Moment Resisting Frames ..................................................... 21 

2.5.3 RC Shear Walls ............................................................................ 22 

2.6 Basics of Seismic Analysis ................................................................ 22 

2.7 Types of RC Slabs.............................................................................. 24 

2.8 Literature Review ............................................................................... 25 

2.9 Summary ............................................................................................ 28 

CHAPTER 3 ................................................................................................ 31 

STRUCTURAL ANALYSIS ...................................................................... 31 

3.1 Introduction ........................................................................................ 32 

3.2 Description of the Studied Buildings ................................................. 33 

3.3 Materials Properties ........................................................................... 37 

3.4 Loads on the Building ........................................................................ 38 

3.5 Validation of Members Sizes ............................................................. 39 

3.5.1 Minimum Slab Thickness ............................................................ 39 

3.5.2 Estimating of Beams Depths........................................................ 44 

3.5.3 Estimating of Trial Sections of Columns..................................... 45 

3.6 Structural Modeling ........................................................................... 48 

3.7 Modeling Criteria ............................................................................... 48 

3.7.1 Members Stiffness ....................................................................... 48 

3.7.2 Base Fixity ................................................................................... 49 

3.7.3 Modeling Phase ............................................................................ 50 

3.7.4 Finite Element Mesh Sensitivity Analysis ................................... 50 

3.8 Models Checking Process .................................................................. 52 

3.9 Verification of Results for Gravity Loads Analysis .......................... 53 



VIII 

3.9.1 Check of Compatibility ................................................................ 54 

3.9.2 Check of Equilibrium ................................................................... 55 

3.9.3 Check of stress-strain relationship ............................................... 56 

3.10 Earthquake Consequences on Structures ......................................... 65 

3.10.1 The Fundamental Natural Period ............................................... 65 

3.10.2 Damping ..................................................................................... 67 

3.11 Ground Motion Input Parameters .................................................... 67 

3.12 Seismic Analysis Approach ............................................................. 70 

3.12.1 Seismic Design Category ........................................................... 70 

3.12.2 Structural Irregularities .............................................................. 73 

3.12.3 Diaphragm Rigidity ................................................................... 74 

3.12.4 The Most legitimated Procedure of Analysis ............................ 74 

3.13 Modal Response Spectrum Method ................................................. 76 

3.13.1 Basic Principles of Modal and Spectral Analysis ...................... 76 

3.13.2 Response Spectrum Concept ..................................................... 77 

3.13.3 Minimum Number of Modes ..................................................... 80 

3.13.4 Modal Combination Technique ................................................. 81 

3.14 Verification of Modal Properties ..................................................... 82 

3.14.1 Verification of the Fundamental Periods ................................... 83 

3.14.2 Verification of the Effective Modal Mass Ratios ...................... 85 

3.14.3 Verification of the Total Displacement of Stories ..................... 89 

3.14.4 Check of the Story Shears .......................................................... 91 

3.14.5 Verification of the Base Overturning Moment .......................... 93 

3.15 Commentaries .................................................................................. 94 

3.16 Design Approach.............................................................................. 96 

3.17 Inelastic Seismic Response of Buildings ......................................... 97 

3.17.1 Fundamental Parameters of Inelastic Behavior ......................... 98 

3.17.2 Other Parameters of Inelastic Behavior ..................................... 99 



IX 

3.18 Design Response Spectrum .............................................................. 99 

3.19 Scaling of Forces ............................................................................ 100 

3.19.1 Seismic Base Shear of ELF Analysis ...................................... 100 

3.19.2 The Base Shear Coefficient ..................................................... 100 

3.19.3 Discussion of the Results ......................................................... 103 

3.20 Drifts and P-Delta Effect ............................................................... 104 

3.20.1 Load Combinations .................................................................. 104 

3.20.2 Redundancy Factor .................................................................. 106 

3.20.3 Orthogonal Loading ................................................................. 107 

3.20.4 The Second Order Effect ......................................................... 108 

3.20.5 The Allowable Story Drift ....................................................... 110 

CHAPTER 4 .............................................................................................. 113 

DESIGN OF SPECIAL MOMENT RESISTING FRAMES ................... 113 

4.1 Introduction ...................................................................................... 114 

4.2 Design Rules of SMRFs ................................................................... 115 

3.4 Design and Detailing of SMRFs ...................................................... 116 

4.4 Modeling of RC Members ............................................................... 116 

4.4.1 Modeling of RC Members Stiffness .......................................... 116 

4.4.2 Reviewing of Diaphragm Rigidity ............................................. 117 

4.5 SMRFs Layout and Proportioning ................................................... 118 

4.5.1 General Requirements of Special Frame Beam ......................... 118 

4.5.2 General Requirements of Special Frame Column ..................... 119 

4.6 Factored Load Patterns .................................................................... 120 

4.7 Preliminary Design Check ............................................................... 123 

4.7.1 Introduction and Overview ........................................................ 123 

4.7.2 Overview of the most Important Points ..................................... 124 

4.8 Scope of the Detailed Design Examples .......................................... 127 

4.8.1 Design of the Selected Beam Span ............................................ 129 



X 

4.8.2 Detailing of the Selected Beam ................................................. 136 

4.8.3 Design of the Selected Column ................................................. 143 

4.8.4 Detailing of the Selected Column .............................................. 156 

4.8.5 Checks on the Beam-Column Joint ........................................... 160 

4.8.6 Detailing of the Beam-Column Joint ......................................... 162 

CHAPTER 5 .............................................................................................. 163 

QUANTITY SURVEYING AND COST ESTIMATION ....................... 163 

5.1 Introduction ...................................................................................... 164 

5.2 Design Results from Different Evaluation Perspectives ................. 165 

5.2.1 Comparison of Concrete and Steel Quantities ........................... 165 

5.2.2 Comparison of Materials Cost ................................................... 169 

CHAPTER 6 .............................................................................................. 171 

CONCLUSIONS, RECOMMANEDATIONS, AND FUTURE WORK 171 

6.1 Conclusions ...................................................................................... 172 

6.1.1 General Conclusions .................................................................. 172 

6.1.2 Specific Conclusions .................................................................. 172 

6.2 Recommendations ............................................................................ 174 

6.3 Future Work ..................................................................................... 176 

REFERENCES .......................................................................................... 177 

APPENDICES ........................................................................................... 196 

APPENDIX A ........................................................................................... 197 

SUPPORTING DOCUMENTS ................................................................ 197 

APPENDIX B ........................................................................................... 200 

CHECKS FOR SIZES OF STRUCTURAL MEMBERS ........................ 200 

APPENDIX C ........................................................................................... 207 

CHECKS FOR GRAVITY LOADS ANALYSIS .................................... 207 

APPENDIX D ........................................................................................... 229 

ELASTIC RESPONSE SPECTRUMS OF PROPOSED SITES ............. 229 



XI 

APPENDIX E ............................................................................................ 232 

ACCUMULATED MODAL MASS PARTICIPATION RATIOS AS 

GIVEN BY SAP2000 ............................................................................... 232 

APPENDIX F ............................................................................................ 236 

SUBSTANTIATION OF FUNDAMENTAL PERIODS AND EFFECTIVE 

MODAL MASS RATIOS ......................................................................... 236 

APPENDIX G ........................................................................................... 249 

VERIFICATION OF THE TOTAL DISPLACEMENT OF STORIES, 

STORY SHEARS, AND BASE OVERTURNING MOMENTS ............ 249 

APPENDIX H ........................................................................................... 274 

𝑷 − ∆ ANALYSIS .................................................................................... 274 

APPENDIX I ............................................................................................. 279 

CHECKS OF DRIFTS LIMITS ................................................................ 279 

APPENDIX J............................................................................................. 289 

CHECKS ON THE GEOMETRIES OF RC MEMBERS IN SMRFs ..... 289 

APPENDIX K ........................................................................................... 292 

COLUMN DESIGN AIDS ....................................................................... 292 

APPENDIX L ............................................................................................ 297 

COLUMNS BUCKLING LOADS ........................................................... 297 

 ب ........................................................................................................... الملخص

 

 

  



XII 

LIST OF FIGURES 

Figure 1.1: 20cm thick filling material overlying 25cm ribbed slab with 

hidden beams .......................................................................... 6 

Figure 2.1: World’s tectonic plates ............................................................. 15 

Figure 2.2: Basic structure of Earth’s surface ............................................. 16 

Figure 2.3: Seismicity map and earthquakes of the DSTF ......................... 17 

Figure 2.4: Tectonic location and borders of the DSTF ............................. 18 

Figure 2.5: The 11 February 2004 earthquake ............................................ 19 

Figure 2.6: The general components of lateral force-resisting systems ..... 21 

Figure 2.7: The effect of inertia forces ....................................................... 23 

Figure 2.8: The resultant of seismic forces ................................................. 24 

Figure 3.1: Typical floor plan of the twelve buildings ............................... 35 

Figure 3.2: Schematic part of the typical section of Model 3N-SR ............ 37 

Figure 3.3: Typical floor plan of Model 3N-SR ......................................... 40 

Figure 3.4: Distinguished panels which govern slab thickness of Model 3N-

SR .......................................................................................... 41 

Figure 3.5: Part of slab to be considered with internal and edge beams .... 42 

Figure 3.6: Cross-sections of internal and edge beams in Model 3N-SR ... 42 

Figure 3.7: Tributary area of an interior column in Model 3N-SR ............. 45 

Figure 3.8: Points where moments were read for sensitivity analysis ........ 51 

Figure 3.9: 3D portal-frame of Model 3N-SR ............................................ 55 

Figure 3.10: CS and MS definition ............................................................. 59 

Figure 3.11: Width of CS and MS along frame X2 in Model 3N-SR ........ 59 

Figure 3.12: Seismic zonation map of Palestine ......................................... 69 

Figure 3.13: Standardized elastic response spectrum referenced by the 

ASCE/SEI 7-10 ..................................................................... 78 

Figure 3.14: Elastic response spectrum of Model 3N-SR .......................... 80 



XIII 

Figure 3.15: Maximum foreseeable side deflection of models on rock 

(Nablus)................................................................................. 95 

Figure 3.16: Maximum foreseeable side deflection of models on soft rock 

(Nablus)................................................................................. 95 

Figure 3.17: Maximum foreseeable side deflection of models on stiff soil 

(Nablus)................................................................................. 96 

Figure 3.18: Maximum foreseeable side deflection of models on soft clay 

(Jericho) ................................................................................ 96 

Figure 4.1: Dimensional guidelines of special frame members ................ 119 

Figure 4.2: RC modules contained in the calculation sheet ...................... 128 

Figure 4.3: Definition of bending moments and beam hinges .................. 130 

Figure 4.4: Maximum horizontal spacing of restrained bars .................... 132 

Figure 4.5: Overhanging flange widths for torsional design .................... 135 

Figure 4.6: Reinforcement details (in centimeters) of the special beam .. 136 

Figure 4.7: Anchorage details for bar size less than ∅25 ......................... 139 

Figure 4.8: End hook of hoops less than 16mm in diameter .................... 141 

Figure 4.9: Spacing details of long. bars in beams ................................... 141 

Figure 4.10: Local axes of the column under design ................................ 143 

Figure 4.11: Cross-sectional dimensions of the restraint T-beam ............ 145 

Figure 4.12: Concepts required for strong column-weak beam theory .... 149 

Figure 4.13: Explanatory figure illustrates the meaning of ℎ𝑥 ................. 150 

Figure 4.14: Probable moments of beams at column top and bottom joints

 ............................................................................................. 153 

Figure 4.15: Reinforcement details (in centimeters) of the special column

 ............................................................................................. 156 

Figure 4.16: End hook details of ∅10 hoops ............................................ 158 

Figure 4.17: Probable moments of beams generating shears on the studied 

joint ..................................................................................... 160 



XIV 

Figure 4.18: Free body diagram of the joint under investigation ............. 160 

Figure 4.19: Reinforcement details (in centimeters) of the beam-column joint

 ............................................................................................. 162 

Figure 5.1: Comparison in beams concrete volume .................................. 165 

Figure 5.2: Comparison in columns concrete volume .............................. 166 

Figure 5.3: Comparison in beams steel reinforcement ............................. 167 

Figure 5.4: Comparison in columns steel reinforcement .......................... 168 

Figure 5.5: Material cost for models in different locations ...................... 169 

 

 

 

  



XV 

LIST OF TABLES 

Table 3.1: Models information and labels .................................................. 34 

Table 3.2: Geometry of models ................................................................... 36 

Table 3.3: Relative flexural stiffness of internal and edge beams .............. 43 

Table 3.4: The average value of the relative flexural stiffness of beams ... 43 

Table 3.5: Ultimate self-weights of structural elements included within the 

tributary area ........................................................................... 45 

Table 3.6: Ultimate weights of distributed loads over the tributary area ... 46 

Table 3.7: Procedures to elect the appropriate mesh size ........................... 52 

Table 3.8: Check of equilibrium due to self-weights of structural elements in 

Model 3N-SR .......................................................................... 56 

Table 3.9: Check of equilibrium due to the distributed loads over slabs of 

Model 3N-SR .......................................................................... 56 

Table 3.10: DDM limitations and checks ................................................... 58 

Table 3.11: Required date before the analysis through the DDM .............. 60 

Table 3.12: Total 𝑀𝑢 value of the slab in the CS calculated by DDM, 

SAP2000, and errors ............................................................... 61 

Table 3.13: Total 𝑀𝑢 value of the beam calculated by DDM, SAP2000, and 

errors ....................................................................................... 62 

Table 3.14: Total 𝑀𝑢 value of the slab in the MS calculated by DDM, 

SAP2000, and errors ............................................................... 62 

Table 3.15: 𝑀𝑢 values and corresponding errors ....................................... 63 

Table 3.16: Maximum expected compressive force acts on the column .... 64 

Table 3.17: 𝑇𝑛 values and their counterpart values of 𝐶𝑢𝑇𝑎 ..................... 66 

Table 3.18: Declaration of prerequisites of SDC ........................................ 73 

Table 3.19: A proof of separation of modes ............................................... 82 

Table 3.20: Seismic DL of stories of Model 3N-SR ................................... 84 

Table 3.21: Seismic SDL of stories of Model 3N-SR ................................ 84 



XVI 

Table 3.22: Verification of the fundamental period of Model 3N-SR ....... 85 

Table 3.23: Verification of effective modal mass ratios of the efficient modes 

of Model 3N-SR ...................................................................... 88 

Table 3.24: Maximum displacements of the generalized SDF systems of 

Model 3N-SR .......................................................................... 90 

Table 3.25: Modal and the maximum expected displacements of floors of 

Model 3N-SR .......................................................................... 91 

Table 3.26: The generalized shear forces, and the total story shears of Model 

3N-SR ..................................................................................... 92 

Table 3.27: The modal overturning moments, and the resultant overturning 

moment of Model 3N-SR ....................................................... 93 

Table 3.28: Scaling up factors of MRS base shears.................................. 102 

Table 3.29: Verification of MRS base shears ........................................... 103 

Table 3.30: Load cases defined inside SAP2000, and required to obtain 𝛿𝑥𝑒 

values .................................................................................... 107 

Table 3.31: Generation of 𝐸𝑄 load cases .................................................. 108 

Table 3.32: Stability analysis of Model 3N-SR ........................................ 110 

Table 3.33: Check of drift limits of Model 3N-SR ................................... 111 

Table 4.1: Checks on limiting dimensions for RC framing members of model 

3N-SR ................................................................................... 120 

Table 4.2: Ultimate loads defined inside SAP2000, and required for strength 

design .................................................................................... 122 

Table 4.3: Newest geometry of models .................................................... 124 

Table 4.4: 𝑇𝑛 versus 𝐶𝑢𝑇𝑎 values of the new models ............................. 125 

Table 4.5: Scaling up factors of MRS base shears of the new models ..... 126 

Table 4.6: Verification of MRS base shears of the new models............... 127 

Table 4.7: Factored axial forces and biaxial moments obtained by computer

 ............................................................................................... 144 



XVII 

Table 4.8: Design forces and moments affecting column upper section .. 147 

Table 4.9: Determination of the design capacity of the biaxial loaded column

 ............................................................................................... 148 

Table 4.10: Column nominal moments matching axial loads .................. 149 

Table 4.11: Column maximum probable moments................................... 152 

  



XVIII 

LIST OF ABBREVIATIONS 

𝐴𝐶𝐼 

𝐴𝐶𝐼 
: American Concrete Institute 

𝐴𝑆𝐶𝐸/𝑆𝐸𝐼 : American Society of Civil Engineers - Structural 

Engineering Institute 

𝐶𝑆 : Column strip 

𝐷𝐷𝑀 : Direct design method 

𝐷𝐿 : Dead load 

𝐷𝑆𝑇𝐹 : Aqaba-Dead Sea Transform Fault 

𝐸𝐿 : Earthquake load  

𝐸𝐿𝐹 : Equivalent lateral force 

𝐹𝐸𝑀 : Finite element method 

𝐼𝐵𝐶 : International Building Code 

𝐽𝐵𝐶 : Jordanian National Building Code for Loads and Forces 

𝐿𝐹𝑅𝑆 : Lateral force-resisting system 

𝐿𝐿 : Live load 

𝑀𝑅𝐹 : Moment resisting frame 

𝑀𝑅𝑆 : Modal response spectrum 

𝑀𝑆 : Middle strip 

𝑃𝐺𝐴 : Peak ground acceleration 

𝑃𝐻 : Plastic hinge 

𝑅𝐶 : Reinforced concrete 

𝑅𝐻 : Response history 

𝑆𝐷𝐶 : Seismic Design Category 

𝑆𝐷𝐿 : Superimposed dead load 

𝑆𝑀𝑅𝐹 : Special moment resisting frame 

𝑆𝑅𝑆𝑆 : Square root of the sum of squares 

𝑆𝑊 : Shear wall 

𝑈𝐵𝐶 : Uniform Building Code 

2𝐷 : Two-dimensional 

3𝐷 : Three-dimensional 

1𝐽 − 𝑆𝐶 : Model sustains a 𝑆𝐷𝐿 = 1𝑘𝑁 𝑚2⁄ , and built in Jericho 

over a soft clay layer 



XIX 

1𝑁 − 𝑅 : Model sustains a 𝑆𝐷𝐿 = 1𝑘𝑁 𝑚2⁄ , and built in Nablus 

over a rock layer 

1𝑁 − 𝑆𝑅 : Model sustains a 𝑆𝐷𝐿 = 1𝑘𝑁 𝑚2⁄ , and built in Nablus 

over a soft rock layer 

1𝑁 − 𝑆𝑆 : Model sustains a 𝑆𝐷𝐿 = 1𝑘𝑁 𝑚2⁄ , and built in Nablus 

over a stiff soil layer 

3𝐽 − 𝑆𝐶 : Model sustains a 𝑆𝐷𝐿 = 3𝑘𝑁 𝑚2⁄ , and built in Jericho 

over a soft clay layer 

3𝑁 − 𝑅 : Model sustains a 𝑆𝐷𝐿 = 3𝑘𝑁 𝑚2⁄ , and built in Nablus 

over a rock layer 

3𝑁 − 𝑆𝑅 : Model sustains a 𝑆𝐷𝐿 = 3𝑘𝑁 𝑚2⁄ , and built in Nablus 

over a soft rock layer 

3𝑁 − 𝑆𝑆 : Model sustains a 𝑆𝐷𝐿 = 3𝑘𝑁 𝑚2⁄ , and built in Nablus 

over a stiff soil layer 

5𝐽 − 𝑆𝐶 : Model sustains a 𝑆𝐷𝐿 = 5𝑘𝑁 𝑚2⁄ , and built in Jericho 

over a soft clay layer 

5𝑁 − 𝑅 : Model sustains a 𝑆𝐷𝐿 = 5𝑘𝑁 𝑚2⁄ , and built in Nablus 

over a rock layer 

5𝑁 − 𝑆𝑅 : Model sustains a 𝑆𝐷𝐿 = 5𝑘𝑁 𝑚2⁄ , and built in Nablus 

over a soft rock layer 

5𝑁 − 𝑆𝑆 : Model sustains a 𝑆𝐷𝐿 = 5𝑘𝑁 𝑚2⁄ , and built in Nablus 

over a stiff soil layer 
 

 

 

 

 

 

 

 

 

 

 



XX 

LIST OF SYMBOLS 

𝐴𝑐ℎ : Cross-sectional area of the column core measured to the 

centers of the outside laterally supported longitudinal 

bars around the perimeter of the column 

𝐴𝑐𝑝 : Area of the gross concrete cross-section to resist torsion 

𝐴𝑔 : Gross cross-sectional area of column 

𝐴𝑗 : Effective cross-sectional area of beam-column joint 

𝐴𝑙,𝑚𝑖𝑛 : Minimum area of longitudinal steel to resist torsion 

𝐴𝑠 : Area of beam flexural steel 

𝐴𝑠,𝑚𝑎𝑥 : Maximum permitted area of beam flexural steel 

𝐴𝑠,𝑚𝑖𝑛 : Minimum required area of beam flexural steel 

𝐴𝑠ℎ,𝑚𝑖𝑛 : Minimum required area of the legs of hoops and crossties 

in each direction per unit length along the column 

confinement zones 

𝐴𝑠𝑡 : Area of column longitudinal reinforcing bars 

𝐴𝑠𝑡,𝑚𝑎𝑥 : Maximum permitted area of column longitudinal 

reinforcing bars 

𝐴𝑠𝑡,𝑚𝑖𝑛 : Minimum required area of column longitudinal 

reinforcing bars 

𝐴𝑡,𝑚𝑖𝑛 : Minimum area of transverse steel to resist torsion 

𝐴𝑣 : Area of shear reinforcement 

𝐴𝑣 𝑠⁄  : Total area of shear reinforcement per unit length along a 

specified length of beam 

𝐴𝑣,𝑚𝑖𝑛 𝑠⁄  : Minimum required area of web vertical bars per unit 

length along a specified length of the member 

𝐴𝑥 : Torsion amplification factor 

𝐵 : Dimension of the structure perpendicular to the direction 

of the earthquake loads 

𝐶 : Horizontal spacing between the center of longitudinal bar 

adjacent to a hoop and the nearest face of the hoop 

𝐶1 : Resultant compressive force of a rectangular 

compression zone (Whitney Stress Block) as described in 

Section 4.8.5 

𝐶𝑑 : Deflection amplification factor 

𝐶𝑠 : Seismic response coefficient 



XXI 

𝐶𝑢 : Factor for upper limit on the calculated period 

𝐷 : Clear spacing between longitudinal bars 

𝐷𝐹𝑏𝑜𝑡 : Moment distribution factor at the bottom of the column 

𝐷𝐹𝑡𝑜𝑝 : Moment distribution factor at the top of the column 

𝐷𝑛 : Maximum prospective displacement of the 𝑛th-mode 

SDF system 

𝐸ℎ : Horizontal seismic load effect 

𝐸𝑐 : Modulus of elasticity of concrete 

𝐸𝑐𝑏 : Modulus of elasticity of beam concrete 

𝐸𝑐𝑠 : Modulus of elasticity of slab concrete 

𝐸𝑣  : Vertical seismic load effect 

𝐹𝑎 : Short period site coefficient 

𝐹𝑣 : Long period site coefficient 

𝐼𝑏 : Moment of inertia of gross section of beam about neutral 

axis 

𝐼𝑐𝑟 : Moment of inertia of cracked section transformed to 

concrete 

𝐼𝑒 : Earthquake importance factor 

𝐼𝑔 : Moment of inertia of gross (uncracked) concrete section 

about the neutral axis, with negligence of reinforcing bars 

𝐼𝑠 : Moment of inertia of gross section of slab about neutral 

axis 

𝐿𝑛
ℎ  : Modal participation factor of an 𝑛th-mode 

𝑀1 : Smaller factored end moment of column 

𝑀2 : Larger factored end moment of column 

𝑀𝑏 : Anticipated base overturning moment of structure 

𝑀𝑏𝑜 : Modal overturning moment 

𝑀𝑛 : Modal mass of the 𝑛th-mode  

𝑀𝑛
∗  : 

Effective modal mass or modal participation mass of an 

𝑛th-mode 

𝑀𝑛𝑏 : Nominal flexural strength of beam 

𝑀𝑛𝑐 : Nominal flexural strength of column 

𝑀𝑛𝑜 : Overturning moments in the 𝑛th-mode 

𝑀𝑜 : Total factored static moment 



XXII 

𝑀𝑝𝑟 : Probable flexural strength of the member at joint faces 

𝑀𝑝𝑟𝑐
𝑏𝑜𝑡 : Probable flexural capacity at the bottom of the column 

𝑀𝑝𝑟𝑐
𝑡𝑜𝑝

 : Probable flexural capacity at the top of the column  

𝑀𝑢 : Factored moment at section 

𝑀𝑢2 : Total design moments of column affecting about local 

axis 3 

𝑀𝑢3 : Total design moments of column affecting about local 

axis 3 

𝑀𝑢2,𝑛𝑠 : Factored moment about local axis 2 of column cross-

section under the design seismic load plus concurrent 

gravity 

𝑀𝑢2,𝑠 : Factored moment about local axis 2 of column cross-

section under the design seismic load 

𝑀𝑢3,𝑛𝑠 : Factored moment about local axis 3 of column cross-

section under the design seismic load plus concurrent 

gravity 

𝑀𝑢3,𝑠 : Factored moment about local axis 3 of column cross-

section under the design seismic load 

𝑀𝑢,ℎ𝑜𝑔𝑔𝑖𝑛𝑔 : Factored hogging moment 

𝑀𝑢,𝑠𝑎𝑔𝑔𝑖𝑛𝑔 : Factored sagging moment 

𝑀11 : Plate bending moment in local direction 1 

𝑁𝑢 : Factored axial force normal to cross-section occurring 

simultaneously with 𝑉𝑢 or 𝑇𝑢 

𝑃𝑐 : Critical buckling load of column 

𝑃𝑐𝑝 : Perimeter of the gross concrete cross-section to resist 

torsion 

𝑃𝑖  : Resultant of the static distributed forces over each floor 

level 

𝑃𝑢,𝑎𝑣𝑔.
𝑏𝑜𝑡  : Average of the design axial loads affecting at the bottom 

of the column for sway in both directions within a plane 

𝑃𝑢,𝑎𝑣𝑔.
𝑡𝑜𝑝

 : Average of the design axial loads affecting at the top of 

the column for sway in both directions within a plane 

𝑃𝑢 : Factored axial force normal to member cross-section 

𝑃𝑢2 : Design uniaxial load of column section at an eccentricity 

𝑒2 



XXIII 

𝑃𝑢3 : Design uniaxial load of column section at an eccentricity 

𝑒3 

𝑃𝑢𝑜 : Maximum design uniaxial load of column section at zero 

eccentricities 

𝑃𝑥 : Accumulated unfactored vertical loads act over the level 

𝑥 

𝑄𝐸  : Seismic effect of orthogonal loading 

𝑅 : Response modification factor 

𝑆1 : 5% damped, dimensionless coefficient of one second 

period horizontal spectral acceleration for rock 

𝑆𝐷1 : 5% damped, design spectral response acceleration 

coefficient at long period for deterministic site 

𝑆𝐷𝑆 : 5% damped, design spectral response acceleration 

coefficient at short period for deterministic site 

𝑆𝑀1 : 5% damped, spectral response acceleration coefficient at 

long period for deterministic site 

𝑆𝑀𝑆 : 5% damped, spectral response acceleration coefficient at 

short period for deterministic site 

𝑆𝑆 : 5% damped, dimensionless coefficient of short time 

period horizontal spectral acceleration for rock 

𝑆𝑎(𝑔) : Maximum spectral response acceleration 

𝑇0 : Period in the boundary between the first and the second 

ranges of periods 

𝑇1 : Fundamental time period of vibration as described in 

Section 3.10.1 

𝑇1 : Resultant tension force developed in the tension zone at 

the level of steel bars as described in Section 4.8.5 

𝑇𝑎 : Approximate fundamental period 

𝑇𝐿 : Long-transition period or the period in the boundary 

between the third range and the fourth range of periods  

𝑇𝑛 : Natural period of vibration 

𝑇𝑆 : Period in the boundary between the second range and the 

third range of periods  

𝑇𝑡ℎ : Threshold torsional moment 

𝑇𝑢 : Design torsional moment at section 



XXIV 

𝑈 : Strength of a member or cross-section required to resist 

factored internal loads 

𝑈1 : Peak value of the displacements of floors in X-Direction 

as given by SAP2000 

𝑉 : Total seismic force at the base of a given structure 

𝑉𝑐 : Nominal shear strength of concrete section 

𝑉𝑒 : Maximum probable shear force at joint faces 

𝑉𝑗 : Shear force at the center of the beam-column joint 

𝑉𝑛 : Nominal shear strength 

𝑉𝑠 : Nominal shear strength provided by shear reinforcement 

𝑉𝑠𝑤𝑎𝑦 : Shear force at section under a design seismic action 

𝑉𝑢 : Factored shear force at section 

𝑉𝑥 : Seismic shear forces between levels 𝑥 and 𝑥 − 1 

𝑊 : Total seismic weight of structure 

𝑍 : Seismic zone factor 

𝑎 : Depth of the equivalent rectangular compressive block 

𝑎𝑝𝑟 : Depth of the equivalent rectangular compressive block 

due to the effect of 𝑀𝑝𝑟 

𝑏𝑐 : Cross-sectional dimension of the column core measured 

to the centers of the outside laterally supported 

longitudinal bars around the perimeter of the column 

𝑏𝑠 : Slab panel width along edge axes in two-way slabs 

𝑏𝑤 : Width of beam web 

𝑐 : Depth of the neural axis measured from the top surface 

of the member 

𝑐1 : Width of column cross-section measured in a direction 

parallel to the longitudinal axis of the beam 

𝑐2 : Width of the column cross-section measured in a plan 

perpendicular to the longitudinal axis of the beam 

𝑐𝑐 : Concrete cover  

𝑑 : Effective depth of member 

𝑑𝑎𝑔𝑔. : Maximum aggregate size 

𝑑𝑏 : Diameter of reinforcing bar 

𝑑𝑏,𝑚𝑖𝑛 : Diameter of the smallest flexural reinforcing bar 



XXV 

𝑑𝑏,𝑚𝑎𝑥 : Diameter of the largest flexural reinforcing bar 

𝑑ℎ : Diameter of one leg of hoop 

𝑒2 : Eccentricity of the factored applied load with respect to 

the local axis 2 of column cross-section 

𝑒3 : Eccentricity of the factored applied load with respect to 

the local axis 3 of column cross-section 

𝑓𝑐
′ : Compressive strength of concrete 

𝑓𝑦 : Yield strength of steel 

𝑔 : Standard acceleration due to gravity (9.81𝑚 𝑠2⁄ ) 

ℎ : Thickness or depth of member 

ℎ𝑚𝑖𝑛 : Minimum thickness or depth of member 

ℎ𝑛 : Building height above the base level 

ℎ𝑠 : Thickness of flange/slab 

ℎ𝑠𝑥 : Height of level 𝑥 over the level 𝑥 − 1 

ℎ𝑤 : Depth of beam excluding the flange 

ℎ𝑥 : Maximum center-to-center spacing of secured 

longitudinal bars around the perimeter of the column 

𝑘 : Effective length factor of column 

𝑙 : Center-to-center span length 

𝑙1 : Span of beam measured center-to-center of the joints 

𝑙2 : Center-to-center span length in direction perpendicular to 

𝑙1 

𝑙𝑑 : Development length in tension for straight bars 

𝑙𝑑ℎ : Development length in tension for hooked bars 

𝑙𝑒𝑥𝑡 : Straight extension at the end of standard hook 

𝑙𝑛 : Clear span length 

𝑙𝑛1 : Clear span length in direction that moments are being 

determined 

𝑙𝑜 : Confinement zone length of a member 

𝑙𝑠𝑡 : Lab splice lengths of reinforcement in tension 

𝑙𝑢 : Unsupported length of column 

𝑚 : No. of shear reinforcing legs at section 

𝑛 : Number of stories above the base as described in Section 

3.14.1 



XXVI 

𝑛 : No. of longitudinal bars set in one layer as described in 

Section 4.8.2 

𝑞𝑢 : Total factored load per unit area of the slab 

𝑟 : Radius of gyration of cross-section as described in 

Section 3.5.2 

𝑟 : Minimum inside bent radius of standard hook as 

described in Section 4.8.2 

𝑟𝑚𝑎𝑥 : Estimated peak value of a response component 

𝑟𝑛 : Force or displacement response component 

𝑠 : Center-to–center spacing of shear reinforcement 

𝑠𝑜 : Center-to-center spacing of hoops within the 

confinement zone length of column 

𝑤𝑖  : Seismic weight of story 𝑖 

𝑤𝑛 : Uniform service (unfactored) weight of the beam web 

𝑤𝑢 : Uniform factored weight of the beam web 

𝛼𝑓 : Beam relative flexural stiffness 

𝛼𝑓1 : Beam relative flexural stiffness in the studied direction 

𝛼𝑓2 : Beam relative flexural stiffness in perpendicular to 𝑙1 

𝛼𝑓𝑚 : Average value of 𝛼𝑓 of all beams surrounding a panel 

𝛽 : Ratio of long to short clear span lengths as described in 

Section 3.5.1 

𝛽 : Ratio of the shear demand to the shear capacity of the 

story as described in Section 3.20.4 

𝛽1 : Factor relates the depth of the equivalent rectangular 

compressive block to the depth of the neural axis 

𝛾𝑐 : Unit weight of reinforced concrete 

𝛿𝑖  : Static lateral deflection at level 𝑖 

𝛿𝑠 : Moment magnifier for unbraced frames 

𝛿𝑥 : Amplified displacement at the floor above, measured at 

center of mass 

𝛿𝑥−1 : Amplified displacement at the floor below, measured at 

center of mass 

𝛿𝑥𝑒 : Elastic displacement at each level 

𝑡 : Extreme-tensile strain of flexural steel 

 : Damping ratio  



XXVII 

𝜃 : Stability coefficient for P-delta effects 

𝜃𝑚𝑎𝑥 : Maximum allowable value of 𝜃 

𝜆 : Factor of concrete mechanical properties 

𝜌 : Redundancy or reliability factor 

𝜌𝑔 : Ratio of longitudinal steel area to the gross column area 

𝜌𝑔,𝑚𝑖𝑛 : Minimum reinforcement ratio in columns 

∅ : Diameter of reinforcing bar  

𝜙𝑛 : Natural mode of vibration 

ϕ : Strength reduction factor 

𝜓𝑐 : Bar concrete cover factor 

𝜓𝑒 : Bar coating factor 

𝜓𝑟 : Bar confining reinforcement factor 

𝜓𝑡 : Bar location factor 

𝜔𝑛 : Natural frequency of vibration 

𝛤𝑛 : Modal participation factor of an 𝑛th-mode 

∆ : Inter-story drift 

∆𝑎𝑙𝑙𝑜𝑤𝑎𝑏𝑙𝑒 : Allowable inter-story drift  

𝛹 : End restraint factor of a member 

Ωₒ : System overstrength factor  

(𝐸𝐼)𝑒𝑓𝑓 : Effective flexural stiffness of the column cross-section 

[𝑈𝑥] : Peak value of the displacements of a structure in X-

Direction 

[𝑉𝑛] : Internal story shears of the 𝑛th-mode 

[𝑉𝑥] : Maximum shear forces in stories 

[𝑓𝑛] : Equivalent static modal elastic forces applied at every 

story level in the 𝑛th-mode 

[𝑚] : Mass matrix 

[𝑢𝑛] : Column vector denotes the displacement envelop of the 

MDF system in the 𝑛th-mode 

[Φ] : Modal matrix 

[𝜄] : Influence vector 

[𝜙𝑛] : Column vector of the 𝑛th mode shape 

[𝜙𝑛
𝑇] : Matrix transpose of column vector of the 𝑛th mode shape 



XXVIII 

Enhancing Earthquake Resistance of Local Structures by Reducing 

Superimposed Dead Load 

By 

Hasan J. Alnajajra 

Supervisor 

Dr. Abdul Razzaq A. Touqan 

Co-Supervisor 

Dr. Monther B. Dwaikat 

ABSTRACT 

The geographical location of Palestine along the Aqaba-Dead Sea Transform 

Fault, the highest seismic active boundary in the Middle East, had put the 

country in a major hazard over the past history. Although seismic hazards 

across the area with relatively low probability, the less attention given 

towards seismic guidelines in both design and construction in the local 

practice is expected to play a significant role on the intensities of the coming 

ground shakings.  

Ribbed slab systems supported on embedded beams and overloaded by 

superimposed dead loads (SDLs) are a common flooring system in the local 

construction industry. Literatures focus on the seismic response behavior of 

ribbed slabs, hidden beams, or heavy constructions indicate an earthquake-

prone buildings. Hence, the existing of such undesirable factors combined 

exceedingly exacerbates the strength of earthquake shaking. 

In this respect, the factor of SDL which is one reason of heavy construction 

is studied. Solid slab with drop beams construction is utilized as a flooring 

system in a set of reinforced concrete framed structures. The framed 



XXIX 

structures are supposed to be built on three different soil profile types in 

Nablus, and one more sensitive soil profile type in Jericho. At every 

particular site, there are three structures sustaining a SDLs of 1kN/m2, 

3kN/m2, and 5kN/m2. This, however, is to investigate the impact of the 

reduction in the SDL at different site effects on the materials cost (Concrete, 

and steel) of frame beams and columns.  

The representative computational models are constructed, analyzed and 

designed using the finite element program SAP2000, Version 19.1.1. The 

analysis is done by means of modal response spectrum method described in the 

Minimum Design Loads for Buildings and Other Structure (ASCE/SEI 7-10), 

whereas the design is accomplished on the basis of the Building Code 

Requirements for Structural Concrete and Commentary (ACI 318-14). 

In final conclusion, the developed approach of reducing SDL form 5kN/m2 to 

1kN/m2 can reduce the materials cost in the skeletal elements of about 25%. 

 



1 

 

 

 

 

 

 

 

 

CHAPTER 1  

INTRODUCTION 

  



2 

1.1 General 

As a natural disaster, earthquakes are an inevitable geophysical phenomenon 

that are neither expected nor prevented. They occur all over the world and cause 

catastrophic havoc to the environment due to the damage of man-made 

structures, injuries, and death toll.  

Annually, people die in natural disasters. 95% of the deaths are due to 

collapse of buildings in earthquakes (Jia and Yan, 2015), mostly in 

developing countries (Kenny, 2009). All around the globe, however, in 2015, 

the Emergency Events Database shows that “earthquakes killed more people 

than all other types of disaster put together, claiming nearly 750,000 lives 

between 1994 and 2013” (CRED, 2015). For the 21st century, Holzer and 

Savage (2013) expectations push towards shocking, about “2.57 ± 0.64” 

millions of fatalities worldwide due to earthquakes. Thus, earthquakes are 

still the supreme expensive disaster in terms of lives lost.  

Without any doubt, the majority of earthquake deaths are attributable to the 

collapse or the damage of building structures rather than the earthquake 

itself. Hence, the high percentage of economic and human losses can be 

controlled or extremely mitigated by immersing an integrated earthquake 

resistance system to the building with an adequate attention to the design, 

detailing and construction methods. 

In general, components of buildings are divided into two main groups. The 

first group encompasses structural components such as beams, columns, 

walls, footings, etc. These skeletal members are used to carry and transfer 



3 

loads on the structure safely to the approved soil stratum. The second group 

is the non-structural components, which are enclosed by the architectural 

components, the mechanical, and the electrical installations. They are 

essential to operate the building and to facilitate the occupant life. 

Experiences from the past revealed that non-structural components are 

vulnerable to earthquakes (Filiatrault et al., 2001, Gillengerten, 2001).  

They contribute to economic losses, threaten the human life and undermine 

the rescue process. For instance, the total loss of 1994 Northridge earthquake 

was $18.5 billion with about 50% participation ratio accounted to non-

structural damage (Qu et al., 2014). Clearly, non-structural elements have 

received a great attention with the advance of performance based design. The 

performance of a building during an earthquake is defined by the 

performance of both structural and non-structural components altogether 

(Taghavi et al., 2003). As a consequence, non-structures protection is well 

insured alongside the structure itself. However, seismic behavior of non-

structural components still requires a proper concern (Ghogare et al., 2016). 

1.2 Problem Statement 

Unlike the developed countries that mainly use steel in multi-story 

construction (Öztürk and Öztürk, 2008), concrete construction is still 

preferable in the Arab world (Rizk, 2010) and in many other countries in the 

region. For instance, nearly 75% of Turkish construction buildings are built 

of reinforced concrete (RC) frames (Vona, 2014). At a local level, 

Palestinians are not familiar with steel construction as much as concrete. 



4 

Concrete buildings are spread in West Bank and Gaza Strip on a very large 

scale (Ministry of local government, 2002).  

Palestine is highly vulnerable to earthquake. In addition, the vast majority of 

inhibited areas are prone to earthquakes (Al-Dabbeek, 2010). Seismological 

studies point to damaging earthquakes that are likely to strike the region (Al-

Dabbeek, 2010). Past earthquakes in different countries of the world 

demonstrated that guidelines and provisions for earthquake resistance have 

been forgotten and easily neglected (Bilham, 2010). Indeed, on contrary to 

what has been anticipated and warned about, most of RC buildings in 

Palestine are designed and constructed regarding gravity loads only. 

Engineers rarely look into the effect of seismic and wind forces through their 

designs (Al-Dabbeek, 2007). 

Nowadays, Engineering Bureaus Board in Palestinian Engineers Association 

is affirming the mandatory of seismic design. An official document on 

26/11/2015 stipulated it for public buildings composed of more than seven 

floors (Appendix A). Henceforth, it is expected that earthquake design in 

Palestine will acquire a great momentum in the near future.  

In West Bank and Gaza Strip, two main systems of buildings floors are 

commonplace, they are RC ribbed slabs, and solid slabs (Deliverable, 2014, 

Ministry of local government, 2002). In the past decades, solid slabs with 

drop beams constituted the floors of overwhelming majority of buildings 

(Kurraz, 2015). For the time being, waffle and ribbed slabs with shallow RC 



5 

beams are prevailing style of roofs in Palestine (Kurraz, 2015), Jordan and 

many other countries (Musmar et al., 2014).  

Hawajri (2016), declared that “bad construction practices” along with many 

other factors make structures in the Palestinian Territories vulnerable to 

earthquakes. Ribbed slabs supported by hidden beams and overloaded by 

high superimposed dead loads (SDLs) are a typical feature in the multi-story 

buildings in Palestine. The above mentioned construction version, in 

author’s opinion, is one of the most principal manifestations of badness in 

the local construction practice. As the thesis topic focuses on the effect of 

SDL, it becomes necessary to note the followings:  

 The SDL adjusted for wearing materials of slab and partitions is “3 to 

4kN/m2” (Deliverable, 2014). This additional weight looks great 

compared to “0.479 to 0.718kN/m2” in the United States (Leet and 

Uang, 2005), for example. Additional weights tend to overweight the 

whole structure without any contribution to develop its stiffness. 

Statically, load carrying members derive their strength form size and 

reinforcement. Dynamically, overweight and enlargement of 

structural members magnify the aggressive dynamic force against the 

building. However, a real example for a ribbed slab with hidden beams 

system and overloaded by filling material is shown in Figure 1.1. 

 



6 

 

 

 

 

 

 

 

 

 

Figure 1.1: 20cm thick filling material overlying 25cm ribbed slab with hidden beams 

It should be noted that in the 2010 earthquake of Haiti, and despite the 

millions of affected peoples and buildings, low-rise residences with 

lightweight roofs have had a positive impact in reducing the damage 

and losses (Deek, 2015). On the other hand, during 1995-Kobe 

earthquake of Japan, the most damage of wooden houses are because 

of “overweight upper floors and heavy roof-tiles of conventional 

Japanese style” (Iwai and Matsumori 2004).  

 Water and plumbing systems are installed inside the infill material 

between the slab and the floor tiles. In this case, liquids leakage will 

be unnoticeable. In the meantime, they deteriorate both concrete and 

reinforcement at an increasing rate. To sum up, concrete deteriorates, 

steel corrodes and slab starts failure. In the latest place, piping systems 

are sway prohibited. In multi-story wood frame buildings, stud walls 



7 

shrinkage caused plumbing breaks (Thornburg et al., 2015). Certainly, 

small ground settlement or ground shaking have the capability to 

damage such vulnerable systems. It is worth mentioning that during 

Northridge earthquake, “the single most disruptive type of non-

structural damage was breakage of water lines inside buildings” 

(Filiatrault et al., 2001). 

The final analysis gives the impression that it will not be enough to know the 

behavior of seismic designed structures in Palestine but, it comes to be so 

urgent to reconsider the present construction scenario in Palestine without 

omitting materials cost. Materials cost, is a critical topic that cannot be 

condoned in developing countries due to the absence of national industry. 

Recently, reviewed by Kurraz (2015), building materials share with about 

40% from the total construction cost of residential buildings in the Middle 

East developing countries. 

1.3 Research Questions  

Seismological studies put Palestinian cities in the seismic risk. Therefore, 

reviewing or altering the construction systems in Palestine seems a must. 

This research project concentrates on two ultimate questions:  

 How does the local construction flooring systems place structures in 

the seismic risk? 

 To what extent does the reduced SDL enhance the seismic behavior of 

the structures? 



8 

1.4 Research Objectives  

1.4.1 Research Overall Objective 

The main idea of this research is to strengthen the earthquake resistance of 

buildings by decreasing the seismic generated forces acting upon their 

skeletons rather than increasing their lateral capacity. This proposed system 

is supposed to be safer, and economical than the today’s system, and it does 

not conflict with the prevailing style of construction in Palestine. For 

instance, building materials available in local markets will be used. Upon the 

research outcomes, this new typology of buildings will be recommended as 

a reasonable system that may be followed in seismic areas.  

1.4.2 Research Sub-objectives  

 To investigate the impact of lessening the SDL on the seismic response 

of the structure. The SDL will be gradually lowered from 5kN/m2 to 

3kN/m2 then, down to 1kN/m2. 

 To display the advantages of the introduced construction system over 

the traditional system not only through a structural point, but also 

through an economic analysis of the results.  

1.5 Research Scope and Limitations 

Four groups of three different models of RC regular buildings of commercial 

and medical use will be traded herein. They are basically distinguished by 

the SDL they support. This difference, of course, will register many 



9 

disparities as the sizes of structural elements in each model and their 

fundamental periods. 

This study is intended primarily for the local community in Palestine, but its 

benefit also extends further to other communities in neighboring countries – 

such as Jordan - that may use the same prototype of construction.  

The Jordanian National Building Code for Loads and Forces (JBC) (MPWH, 

2006) will be utilized for live load intensity. Seismic loads will be calculated 

as per the International Building Code Provisions (IBC 2015) (International 

Code Council, 2014), and the Minimum Design Loads for Buildings and 

Other Structures (ASCE/SEI 7-10) (ASCE, 2010). Finally, design and 

detailing of the structure will be carried out according to the Building Code 

Requirements for Structural Concrete and Commentary (ACI 318-14) (ACI 

318, 2014). 

The impact of earthquakes is not limited to ground shaking, other effects 

such as tsunami for example, are not taken in consideration throughout the 

design procedures of buildings and similar constructions. These are 

advanced topics. Usually, it is preferable to avert constructing works at 

locations where such hazard is potential (NIBS, 2012). It remains to mention 

that non-mandatory considerations like thermal and sound insulations are 

excluded from the comparison in all cases.  

1.6 Structure of the Thesis  

This research thesis consists of six chapters and twelve appendices. The 

followings are a summary of the contents of the chapters: 



10 

Chapter 1 (Introduction). Chapter 1 sets the problem statement, research 

questions, research objectives as well as research scope and limitations.  

Chapter 2 (Literature review). This chapter includes a description of an 

earthquakes mechanism, the seismicity of the region with relevant data, the 

concept and requirements of earthquake resistance, and principles of seismic 

analysis. This chapter also contains a detailed literature review on heavy 

constructions and flooring systems in the context of vulnerability to 

earthquakes. Finally, the overall image of the suggested models is emerged.  

Chapter 3 (Structural analysis). In this chapter, structural models and 

construction sites are carefully selected, loads and modelling criteria are 

outlined. Analysis results obtained from the computer aided analysis 

software (SAP2000) are verified thorough a series of hand calculation 

procedures. 

Chapter 4 (Design of special moment resisting frames). This chapter 

highlights the concept of sway special frames, predesign requirements 

according to the ACI 318-14 Code. A detailed design calculation sheets for 

beam, column, and a beam-column joint in a special moment resisting frame 

are also involved. 

Chapter 5 (Quantity surveying and cost estimation). In this chapter, the 

quantities of structural materials (concrete, and steel) consumed by skeletal 

members in the designed models are computed. Material costs are estimated 

as well. Final results are graphically presented, then discussed as a 

comparison among different models. 



11 

Chapter 6 (Conclusions, recommendations and future work). Chapter 6 

provides conclusions drawn from the research with a focus on what has been 

observed from results presented in Chapter 5. Recommendations and 

suggestions for future works are also presented. 

  



12 

 

 

 

 

 

 

 

 

CHAPTER 2  

LITERATURE REVIEW 

 

  



13 

2.1 Introduction 

Earthquakes have disastrous consequences for most societies. A few seconds 

of land instability are enough to bring annihilation to the buildings and cause 

significant number of dead, wounded, and missing people. “In recent 

earthquakes, buildings have acted as weapons of mass destruction. It is time 

to formulate plans for a new United Nations mission — teams of inspectors 

to ensure that people do not construct buildings designed to kill their 

occupants” Bilham (2010) said. 

Predominantly, the concept of RC structures sounds familiar to humankind's. 

Yet, over the preceding earthquakes, a lot of extensive damaged RC structures 

have been observed across the world (B.S and Tajoddeen, 2014). The issue can 

be summed up, but not limited to, negligence of the minimum requirements of 

code and provisions (mass irregularities, soft story, etc.), negligence of seismic 

design, ill-conceived construction practice, use of poor material, and unskilled 

labor (Isler, 2008). 

Whatsoever, the behavior of multi-story RC structures that are designed and 

implemented in accordance with the seismic requirements could not be 

denied (Pampanin, 2012). Despite the recurrence of earthquakes in their 

home country, Japanese succeeded in mitigating the collapse of buildings 

through the seismic design of almost all buildings and the good Japanese 

code and provisions (Haseeb et al., 2011). Elsewhere, well designed RC 

structures in Nepal demonstrated an ability to afford earthquakes of 



14 

magnitudes up to 7.8. They suffered only slight non-structural damage 

(Adhikari et al., 2015). 

However, the choice of thesis topic is carefully selected and argued 

throughout this text, detailing of the seismicity of the region, and description 

of real-life structures. In the meantime, scholarly materials are also analyzed 

comprehensively in order to derive a better feedback, and to obtain a real 

understanding into the sensitive issues. 

2.2 Earthquakes Phenomena 

2.2.1 Causes of Earthquakes 

An earthquake is a broad-banded natural vibration motion of the ground 

caused by either natural endogenous phenomena like volcanic activities and 

tectonic processes, or by artificial events as explosions and collapse of 

cavities. Though, seismologists believe that 90 percent of all earthquakes 

phenomena are attributable to the tectonic movements (Armouti, 2015). 

Thus, earthquakes can most reliably be explained through tectonic actions. 

2.2.2 Theory of Plate Tectonics  

Since it was launched in the 1960s (Day, 2012), it still represents the global 

perspective to the worldwide seismicity model. According to the theory, as 

illustrated in Figure 2.1, Earth’s crust is broken into at least 15 (Dowrick, 

2003) large, rigid slabs of lithosphere called tectonic plates that sometimes 

comprise many continents.  



15 

 

 

 

 

 

 

 

 

Figure 2.1: World’s tectonic plates (U.S. Geological Survey, 2016) 

As shown in Figure 2.2, tectonic plates are underlined by the asthenosphere 

layer. Asthenosphere is a soft viscoelastic shell that lets plates to move 

against each other. The adjacent plates are prevented from differential 

displacements due to the friction at their adjoining boundaries. Friction 

forces induce shear stresses in a form of strain energy that is stored at plate 

boundaries. The surface lies between two adjacent boundaries along which 

movement is prevented is physically termed faults and considered the source 

of most earthquakes (Udías et al., 2014). The moment that stored energy 

increases beyond the level that material strength can hold the adjacent 

boundaries, fracture and slippage occur along the fault interface causing a 

phenomenon called the elastic rebound. The elastic rebound releases the 

stored energy randomly in all directions surrounding the fault in the form of 

shock strain waves which points to the onset of an earthquake incident. 



16 

Seismic strain waves of two types are propagated. They are body waves and 

surface waves. These two types are further subdivided into two types: P 

waves, and S waves then, Love waves, and Rayleigh waves. 

 

Figure 2.2: Basic structure of Earth’s surface (Bangash, 2011) 

2.3 Seismicity of Palestine 

2.3.1 Earthquake Sources in Palestine  

The State of Palestine is historically proven to be prone to earthquakes. 

These earthquakes were a gloom events to Palestinians due to their horrible 

damage and the large number of deaths, estimated in hundreds and probably 

in thousands (United Nations, 2014). The geographical location of Palestine 

puts the country along the Aqaba-Dead Sea Transform Fault (DSTF) (Levi 

et al., 2010) which is the most seismically active plate boundary in the 

Middle East (Ben-Avraham et al., 2005), chiefly eastern Mediterranean 

territories (Moustafa, 2015, Levi et al., 2010). Figure 2.3 demonstrates a lot 

of earthquakes that hit Palestine during the past centuries. Rightly, they 

struck along the DSTF (Al-Dabbeek et al., 2008).  



17 

 

Figure 2.3: Seismicity map and earthquakes of the DSTF (Al-Dabbeek et al., 2008) 

The DSTF controls the relative movement between Arabian plate to the east 

and Sinai sub-plat to the west. It is an approximately 1000km fault long 

(Klinger et al., 2015, Sadeh et al., 2012), oriented from the red sea at south 

to Taurus mountains zone in Turkey to the north (Arango and Lubkowski, 

2012, Klinger et al., 2000b). Figure 2.4 is a topographic map for the tectonic 

location and borders of the DSTF. Naturally, it can be inferred from the 

figure that DSTF sets the whole Levant at a significant hazard of earthquakes 

(UNDP, 2014).  



18 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 2.4: Tectonic location and borders of the DSTF (Garfunkel et al., 2014) 

2.3.2 Historical Overview for the Dead Sea Earthquakes  

Going back to the past, historical archives states that the DSTF has a notable 

historical record of damaging earthquakes with a magnitude of nearly seven 

(Klinger et al., 2000a). The eleventh of July 1927 registered the largest 

devastating earthquake. Its epicenter was at the north to Jericho with a 

magnitude of 6.3 (Al-Dabbeek and El-Kelani, 2005). Locally, this event is 



19 

called Nablus earthquake. Earthquakes are not discontinued, for instance, the 

eleventh of February 2004 earthquake which displayed in Figure 2.5, was 

epicentered in the Dead Sea and scored a magnitude of 4.9 (Hawajri, 2016).  

 

Figure 2.5: The 11 February 2004 earthquake (Hawajri, 2016) 

The aforementioned earthquake was felt in Jordan, Gaza Strip and many 

cities in the West Bank. Fortunately, its damage was trivial with no casualties 

(Al-Dabbeek and El-Kelani, 2005). Then, it was followed by many other 

earthquakes that sometimes left a moderate structural and a non-structural 

damages for many local RC buildings (Hawajri, 2016).  

More or less, the seismotectonic setting of the region indicates that the Dead 

Sea area still an active source for many damaging earthquakes beyond a 

magnitude of 6. They are expected to take place any time in the near future 



20 

and to leave formidable destruction and losses due to the high vulnerability 

of existing buildings in Palestine (Hawajri, 2016). 

2.4 Earthquake Resistant Buildings 

The foremost function of different kinds of buildings and structures is to 

support and transfer gravity loads safely (Kevadkar and Kodag, 2013). 

Gravity loads are vertical actions and common in nature, in a form of dead 

loads (DLs), live loads (LLs), and snow loads. Out of these vertical loads, a 

structure may experience a temporarily horizontal forces resulted from 

earthquakes or winds. Sometimes, they have considerable intensities and 

cannot be ignored. However, buildings and structures designed for gravity 

loads might not accommodate lateral loads (Rai et al., 2011). Therefore, 

providing structures with structural systems that have a sufficient strength 

for gravity loads coupled with a suitable stiffness for occasional horizontal 

loads, is really worthwhile. 

2.5 Lateral-Force Resisting Systems 

RC building structures resist gravity loads through the integration of slabs, 

columns, bearing walls, and footings. Meanwhile, they resist seismic loads 

through the integration of diaphragms, framing columns, shear walls, and 

footings. Figure 2.6, displays the common components of gravity load-

carrying system, and lateral force-resisting system (LFRS).  



21 

      

Figure 2.6: The general components of lateral force-resisting systems (Moehle, 2015) 

It is worth mentioning that an earthquake resistant building does not only 

require a well-defined LFRS. Commitment to buildings code, seismic 

reinforcement, proper detailing, engineering supervision, and using of 

materials with a good quality are also needed (Moehle, 2015). 

2.5.1 Structural Diaphragms 

In RC buildings, whereas slabs carry and transmit gravity loads to the 

bearing system of the structure, they act as diaphragms to transmit and 

distribute horizontal loads to the LFRS, and to tie the structure together such 

that it operates as one unit in the case of an earthquake threat. 

2.5.2 RC Moment Resisting Frames 

Moment Resisting Frames (MRFs) are a network of RC horizontal members 

(beams) and vertical members (columns) connected together at rigid joints. 



22 

They are designed for both gravity and earthquake loads. Most often, they 

generate an adequate lateral resistance through bending resistance of girders 

and columns (Yakut, 2004). MRFs offer a good level of ductility such that 

they undergo large lateral deflections to dissipate a great energy under 

violent earthquakes (Elnashai and Di Sarno, 2008). MRFs are economical up 

to 20 – 25 stories (Arum and Akinkunmi, 2011). 

2.5.3 RC Shear Walls  

Shear walls (SWs) are RC vertical plates with constant cross sections ranging 

in width from 200 mm to 400 mm (Kevadkar and Kodag, 2013) along the 

entire height of construction. SWs frequently extend from the foundations to 

the building upstairs. They are mainly designed for earthquake loads; their 

influence by gravity loads is usually of minor importance (Priestley and 

Paulay, 1992). Contrariwise to MRFs, SWs are used to control lateral 

displacements (Agrawal and Charkha, 2012). However, their behavior is not 

as ductile as that of MRF (Chen and Lui, 2006). As a final point, SWs are 

economically effective for buildings up to 25 - 30 stories (Elnashai and Di 

Sarno, 2008).  

2.6 Basics of Seismic Analysis  

Perhaps what distinguishes earthquakes from most other dynamic 

excitations, is that earthquakes apply in a form of support motions rather than 

by external forces applying on the above-ground portion of buildings 

(Clough and Penzien, 2003). For further interpretation, in the event of 



23 

earthquakes, the internally developed inertia forces due to the vibration 

(acceleration) of structure mass (diaphragm and all the elements that is 

rigidly attached to it) are the main causative of deformations and structural 

deteriorations, in lieu of external imposed pressures (Booth, 2014, Taranath, 

2004). 

If the ground and the base of the building shown in Figure 2.7 go a sudden 

incipient motion to the left, the ground floor and its contents will oppose to 

move with the base because of the inertia of their mass that resists the motion 

(Taranath, 2004).  

 

Figure 2.7: The effect of inertia forces (Arya et al., 2014) 

As a result, the story with its contents will shift in an opposite direction just 

like if the structure is withdrawn to the right by a fictitious force, i.e. inertia 

force (Arya et al., 2014). These imaginary unseen forces are known as 

seismic loads (Ishiyama et al., 2004). Seismic loads are reversible in nature, 

and equal a portion of the weight of the building in their intensities (Elnashai 

and Di Sarno, 2008).  



24 

Most of the mass of buildings is concentrated at their ceilings (Ishiyama et 

al., 2004), subsequently, seismic loads are more influential at the roofs of 

buildings as shown in Figure 2.8.  

 

Figure 2.8: The resultant of seismic forces (Arya et al., 2014) 

In fact, the deformation process is more complicated than what has been 

explained earlier. They may be described in three dimensions because of the 

simultaneous three dimensional ground motion. However, seismic loads 

caused by the horizontal accelerations are only regarded for earthquake 

design; vertical component is less than the horizontal ones (Elnashai and Di 

Sarno, 2008, Chen and Lui, 2006), and is also counteracted by the inherent 

strength of members provided for gravity design (Priestley and Paulay, 

1992). 

2.7 Types of RC Slabs 

Civil engineers, labors, and contractors have practiced different traditional 

typologies of concrete slabs. Slabs could be classified with reference to 

different criteria such as the shape of plan, and the method of construction. 

Too, slabs may be assorted to one-way slabs and two-way slabs (McCormac 



25 

and Brown, 2015, Aghayere and Limbrunner, 2014, Subramanian, 2014, 

Nilson et al., 2010). 

If the ratio of one slab panel length to its width is greater than 2, the slab is 

recommended to be designed as one-way slab, otherwise, it is a two-way 

slab. When the one-way slab is made with voids, it is called one-way ribbed 

slab (one-way joist system). If not, it is assigned to be one -way solid slab. 

A specific types of two-way slabs are waffle slabs (two-way joist systems), 

flat plates (two-way solid slabs) that are directly supported by columns, and 

flat slabs which are flat plates with column capitals and/or drop panels. 

However, the selection of slab type depends on economy, aesthetic features, 

loading, and lengths of the spans (Hassoun and Al-Manaseer, 2015). 

At present, hollow slab systems have been developed by means of modern 

technologies. The created slab saves up to 35% of the dead weight of solid 

slab (Gavgani and Alinejad, 2015). Despite the almost equalized bending 

capacity of the two systems (Johnson et al., 2015), there still a main 

difference in shear resistance (Churakov, 2014) which is highly dropped in 

the voided slab systems.  

2.8 Literature Review 

Several researches on the seismic behavior of RC structures have recently 

been conducted worldwide and aimed to provide basic data on the safety and 

cost-effective versions of construction. 

Mohamed (2014), investigated the lateral stability of buildings roofed by 

ribbed slabs. He highlighted that ribbed slabs of six stories, bare frames, RC 



26 

commercial building failed to satisfy the requirements of Egyptian Code 

response spectra. It has been well documented that deficient side resistance 

and the resulting building damage have been due to the weak frame actions 

resulted by the lack of deep beams. Therefore, he pointed that there is a need 

to retrofit these non-seismic designed buildings to improve their seismic 

capacity. In a closely related theme, Novelli et al. (2014) studied the seismic 

vulnerability of Wadi Musa city in Jordan on the basis of fragility curves. 

Fragility curves are utilized to estimate the value of the ground acceleration 

at which the failure capacity of buildings is exceeded (Kostov and Vasseva, 

2000). Novelli and partners were surprised when fragility curves of modern 

buildings that have one way ribbed slabs of 250mm depth go over those for 

foregoing buildings roofed by flat slabs with a thickness of 120mm. They 

explained the situation on the basis that modern structures were composed 

of heavy slabs settled on one way frames. This led to sizeable increment in 

mass of the roofs, which was not met by parallel enlargement in lateral 

capacity of frames. Thereupon, they appear most vulnerable to the seismic 

risk. In another approach, Barbat et al. (2009), claimed that there is no 

indication inside the Eurocode 8 (CEN, 2005), International Building Code 

(International Code Council, 2004), and Uniform Building Code (UBC 97) 

(International Conference of Building, 1997) to consider systems of waffled 

slabs as component of an earthquake resisting system. Then, they showed 

that their probabilistic analysis provides a collapse probability of nearly 1% 

for moment resisting frame systems and 30% for waffled slab floors systems. 



27 

Finally, they recommended the depth beams as an only possible solution to 

develop the lateral stiffness of waffled slab floors buildings.  

Another comparison was carried out by Kyakula et al. (2006). They pointed 

out that at shorter spans, and because of standard sizes of the manufactured 

blocks and minimum required thickness of topping, the total depth of the ribbed 

slab exceeds the required thickness of the solid slab. At medium spans, ribbed 

slabs need shear reinforcement, while solid ones do not need. For longer spans, 

topping increases the cost unreasonably. Kyakula et al. (2006), restated that 

keys and groves provided in hollow clay blocks enhanced the friction resistance 

to grip the blocks firmly in concrete. Even so, the current shape of manufactured 

blocks weakens shear strength of the slab.  

Paultre et al. (2013) provided information on the state of construction in 

Haiti, and the main causes of damage of too many engineered buildings 

during the 12 January 2010 Haiti earthquake. They indicated that two way 

ribbed slabs are inadequate in zones of high seismic activity. Instead, lighter 

solid slabs shall be used. During earthquake events, concrete blocks in joist 

slabs may detach or crash and endanger people's lives. 

Pardakhe and Nalamwar (2015), examined the effect of using light weight 

block masonry on the overall cost of construction for earthquakes. They 

explained that the using of light weight concrete blocks in walls has reduced 

the total construction cost of structures by approximately 29% of that 

required for constructions loaded with red brick blocks. Hence, lightweight 

construction is more cost-effective. 



28 

Taqieddin (2014), discussed the serviceability of wide-hidden beams under 

vertical loadings. He went to that hidden beams demonstrate large deflection 

values due to their shallow depths. The amount of compression steel 

reinforcement needed to recover long term deflection values at midspan 

overstepped the amount of reinforcement needed for flexure. He also asserts 

on that regardless the aesthetic appearance, other options are better on all 

other aspects.  

Arakere and Doshi (2015), checked the performance of multi-story building 

made of drop beams and hidden beams during an earthquake ground 

excitation. They set the precedence to drop beams in the seismic design. 

Hidden beams result in 10% increment in both drift of model and base shear 

due to the decreased stiffness of the structure and its high fundamental 

period. 

2.9 Summary 

Seismic design theory defines the seismic forces in a form of horizontal 

actions equal a portion of the weight of the building (Elnashai and Di Sarno, 

2008). As most of the building weight is concentrated at roofs and floors 

(Ishiyama et al., 2004); Kamali et al. (2014) introduced a perception that 

“one of the most important and remarkable solutions for improving the 

general stability of the structure is roof lightweight”. 

In the midst of all the above, the outline of thesis project is:  



29 

 To use two way solid slabs with drop beams and false ceiling instead 

of present-day system which is two way ribbed slab with hidden 

beams. 

 Beyond that, SDL over that slab will be decreased to the lowest 

permitted level. 

 Then, pipes installed beneath slabs and hid through false ceiling.  

Undoubtedly, the event of earthquake shakes building structure, its contents, 

and occupants. Therefore, designers must pay an attention towards seismic 

analysis and design of building structure. The suggested system, however, is 

expected to be an effective key to get rid of many problems: 

 This category of construction is desirable in seismic zones due to the 

higher lateral stiffness provided by drop beams. For tall buildings 

established in regions of seismic activity; “ribbed-slab-column 

frames” is convenient as a gravity load structural system (El-Shaer, 

2014).  

 Solid slabs do not contain any blocks. Accordingly, neither blocks 

anchorage is needed, nor blocks downfall is expected. 

 Covering materials do not take part in structural stiffness. Thereby, 

less infill material over slab will underweight the slab without 

prejudice to stiffness. This contributes not only to a less construction 

amounts of concrete and steel, but also enhances the dynamic 

resistance of the building against winds and earthquakes to the extent 

that it may allow to nullify the P-Delta effect. The notion of P-Delta 



30 

effect automatically means to induce an extra internal forces inside 

structural members. 

 The using of flexible fittings and the placement of pipes underneath 

floors let them move freely and stop damage. Therein, this system is 

compatible with the performance based design principle and turn to 

save money, time, and effort exerted in maintenance. As conventional 

rough calculations, non-structural systems account for 40% of the total 

estimated cost of buildings.  

 

  



31 

 

 

 

 

 

 

 

 

CHAPTER 3 

STRUCTURAL ANALYSIS 

  



32 

3.1 Introduction 

At all the earthquakes, the stability of building structures is disturbed through 

a direct action (ground motion) or indirect actions (soil liquefaction, 

landslide hazard, etc.) (Haseeb et al., 2011). Admittedly, buildings collapse 

during earthquakes is ultimately attributable to the ground movement 

(Moehle, 2015). Hence, ground motion hazard is still capturing the attention 

of engineers who are interested in the seismic design of buildings. 

Pursuing this further, the method, in which a structure responds when it is 

exposed to a sudden ground shaking, is governed by two factors (Panas 

2014). The first factor is with high inaccuracy since it depends on an 

imperfect field data; this is the intensity of earthquake excitation. The second 

factor is the goodness of the structure, and estimated by its seismic design, 

detailing and the construction process.  

The philosophy of earthquake design is that the design must fulfil the 

following objectives (Bertero, 1996): 

 Avoid non-structural damage due to minor earthquakes which often 

occur.  

 Avoid structural damage and to limit non-structural damage due to 

moderate earthquakes that occur betweenwhiles.  

 Prevent downfall or the significant structural damage due to strong 

earthquakes which scarcely occur.  

The foregoing precepts will not be really accomplished unless the building 

structure has an adequate strength, stiffness, and ductility alongside with a 



33 

reasonable extra implementation cost, maintenance throughout its service, 

and to abandon some architectural styles even if they were familiar in gravity 

loads design (Bertero, 1996). 

3.2 Description of the Studied Buildings 

Improving the resistance of structures by increasing members strength to 

withstand seismic forces is not always preferable (Barmo et al., 2014). 

Irrespective of the proven performance of light construction over the massive 

class as discussed previously, specifically, the study targets to quantify the 

positives of reducing SDLs in terms of engineering and economy indexes. 

What makes the value of the study is that it encompasses nine commercial 

buildings built on three different host sites (rock, soft rock, and stiff soil) in 

Nablus. Moreover, it is broadened to include Jericho, the nearest Palestinian 

city to the DSTF, with three hospitals built on a soft clay soil. The study, 

however, utilizes a group of three RC models supposed to be contiguous at 

the abovementioned four different locations. To make it easier for the reader, 

each model adjusted a different designation as shown in Table 3.1. 

 

 

 

 



34 

Table 3.1: Models information and labels 

 

Hereinafter, the name of every model consists of two parts. The first number, 

in the prefix, is the SDL sustained by the structure (kN/m2), and the second 

letter refers to the name of the city where the model is built, whereas the 

suffix points to the soil profile beneath the structure. For example, the 

designation 3N-SR means, a model sustains a 𝑆𝐷𝐿 = 3𝑘𝑁 𝑚2⁄ , and built in 

Nablus over a soft rock layer. 

Every model characterizes a building of ten stories above the grade. The 

twelve models, are alike in the framing plan, three bays by three bays, as 

shown in Figure 3.1. In all models, the external perimeter walls for any 

model are of glass. The LFRS for each model is RC special-moment resisting 

frames in each direction, and of 6m center-to-center apart forming 18.0m × 

18.0m floor plan building.  

No. SDL (kN/m2) Occupancy City Soil Profile  Model Designation
1 1 Commercial Nablus Rock 1N-R
2 3 Commercial Nablus Rock 3N-R
3 5 Commercial Nablus Rock 5N-R
4 1 Commercial Nablus Soft rock 1N-SR
5 3 Commercial Nablus Soft rock 3N-SR
6 5 Commercial Nablus Soft rock 5N-SR
7 1 Commercial Nablus Stiff soil 1N-SS
8 3 Commercial Nablus Stiff soil 3N-SS
9 5 Commercial Nablus Stiff soil 5N-SS
10 1 Hospital Jericho Soft clay 1J-SC
11 3 Hospital Jericho Soft clay 3J-SC
12 5 Hospital Jericho Soft clay 5J-SC



35 

 

Figure 3.1: Typical floor plan of the twelve buildings 

In all models, gravity loads are distributed and sustained by 13cm thick, two-

way solid slabs supported by rectangular drop continuous beams run in both 

directions, and set centrally on columns. In every model, beams and columns 

are kept in the same size. The clearance of all stories is identical in all 

models, it is 2.95m per single story. Table 3.2, however, shows the other 

consequent differences between models. It should be noted that the 

dimensions shown in Table 3.2 have been gotten after a number of iterations 

so that, they are expected to realize the forthcoming requirements and 

checks. 

For research purposes, all of the calculations regarding Model 3N-SR will 

be covered herein in detail. However, important parts of figures and 



36 

calculations of the other models may be briefly addressed here, while the rest 

will be inserted into the appendices. However, Figure 3.2 shows a typical 

section through Model 3N-SR. 

Table 3.2: Geometry of models 

 

 

 

 

 

 

 

 

Single story Structure Width Depth Length Width
1N-R 10 3.4 34 130 650 400 650 650

1N-SR 10 3.4 34 130 650 400 650 650
1N-SS 10 3.4 34 130 650 400 650 650
1J-SC 10 3.4 34 130 650 400 650 650
3N-R 10 3.55 35.5 130 700 450 700 700

3N-SR 10 3.55 35.5 130 700 450 700 700
3N-SS 10 3.55 35.5 130 700 450 700 700
3J-SC 10 3.55 35.5 130 700 450 700 700
5N-R 10 3.7 37 130 750 500 750 750

5N-SR 10 3.7 37 130 750 500 750 750
5N-SS 10 3.7 37 130 750 500 750 750
5J-SC 10 3.7 37 130 750 500 750 750

Columns Sections (mm)
 Model 

No. of 
Stories

 Vertical Height (m) Thickness of 
Slabs (mm)

Beams Sections (mm)



37 

 

Figure 3.2: Schematic part of the typical section of Model 3N-SR 

3.3 Materials Properties  

RC is a construction material that is commonly used in every type of 

construction. If “economically designed and executed”, it became 

competitive structural material (Hassoun and Al-Manaseer, 2015). Plain 

concrete has a relatively high compressive strength, and low strength in 

tension. Therefore, it is primarily reinforced with steel in a form of rounded 



38 

bars to compensate its weakness in tension. This final product called RC and 

has a unit weight (𝛾𝑐) of 25𝑘𝑁/𝑚3 according to the JBC (2006). The 

strength of plain concrete and steel bars are, typically, expressed in terms of 

compressive strength of concrete (𝑓𝑐
′), and yielding stress of steel (𝑓𝑦). 

For all structural elements composing the assessed models, concrete strength 

of 𝑓𝑐
′ = 23.5𝑀𝑃𝑎, and steel strength of 𝑓𝑦 = 420𝑀𝑃𝑎 are used. 

3.4 Loads on the Building 

Dead and live loads in addition to seismic loads acting in the horizontal 

direction will only be considered during the analysis and design of models.  

DL is taken as the weight of the structure itself, plus the SDL. The weight of 

the structure is determined by the foreknowledge of the dimensions of 

structural members and unit weights. The structural components of models 

are inherently RC. SDL is the part of DL that is assigned for partition walls, 

tiles and accessories, and building utilities (water pipes, air conditioning 

ducts, etc.) (Leet and Uang, 2005). SDLs (1kN/m2, 3kN/m2, and 5kN/m2) are 

excerpted from the local experience of the author. Saudi Building Code 

(SBCNC, 2007) points 0.4kN/m2 as an equivalent distributed DL for the 

glass frame walls. Really, this value is marginal, it composes only 8 percent 

(𝑆𝐷𝐿 = 5𝑘𝑁 𝑚2⁄ ) to 40 percent (𝑆𝐷𝐿 = 1𝑘𝑁 𝑚2⁄ ) of the SDLs. Thus, 

perimeter glass walls and their loading effect are not worthwhile. 

LLs are those produced by the occupancy of the building. The JBC adjusts 

4kN/m2 as a LL for both commercial and hospital buildings. 



39 

Seismic loads cause a multidirectional vibration to buildings resting on the 

earth. Since the targeted structures are originally symmetrical and uniform, 

seismic loads along either one of the two horizontal – orthogonal - directions 

yield the same results, however, the attention is paid on the global X-

Direction. 

3.5 Validation of Members Sizes 

Initial sizes of members composing a structure are required even in the case 

of computer analysis. They are ordinarily prerequisite to perform an 

elementary frame analysis, and to obtain a rough overview of the quantities 

of construction materials for cost estimation.  

3.5.1 Minimum Slab Thickness 

Fundamentally, the preliminary depths of slabs and beams are estimated to 

satisfy serviceability requirements. Figure 3.3 is the typical floor plan of 

Model 3N-SR. With reference to Table 3.2, note that:  

 Slab thickness = 130mm. 

 Beams sections are of 700mm width by 450mm total depth. 

 Columns sections are of 700mm length by 700mm width. 

As slab panels are rectangular in shape, and the ratio of long side (6000mm) 

to short side (6000mm) is 1.0; two way action is expected. 



40 

 

Figure 3.3: Typical floor plan of Model 3N-SR 

Section 8.3.1.2 of the ACI 318-14 Code sets the minimum thickness of two 

way slabs resting on beams on all sides to control deflection. Slab thickness 

depends mainly on the average value of relative flexural stiffness of all 

beams (𝛼𝑓𝑚) on the perimeter of the panel. Beam relative flexural stiffness 

(𝛼𝑓) is given by the ACI 318-14 Code in Section 8.10.2.7 as: 

        𝛼𝑓 = 
𝐸𝑐𝑏𝐼𝑏
𝐸𝑐𝑠𝐼𝑠

                                     [3.1a] 

Where: 

𝐸𝑐𝑏 and 𝐸𝑐𝑠 are the modules of elasticity of beam and slab concrete.  

𝐼𝑏 is the moment of inertia of gross section of beam about neutral axis. 



41 

𝐼𝑠 is the moment of inertia of gross section of slab has a width defined 

laterally by the centerlines of panels at each side of the beam? 

        𝛼𝑓 = 
𝐼𝑏
𝐼𝑠
                                           [3.1𝑏]…𝑓𝑜𝑟 𝑡ℎ𝑒 𝑠𝑎𝑚𝑒 𝑐𝑜𝑛𝑐𝑟𝑒𝑡𝑒. 

Figure 3.4 shows three different panels to be checked during the 

determination of minimum slab thickness. They are: 

 Corner panel, with two edge beams, and two internal beams. 

 One edge panel, with one edge beam, and three internal beams. 

 Internal panel, with four internal beams. 

 

 

Figure 3.4: Distinguished panels which govern slab thickness of Model 3N-SR 

 



42 

Effective Sections of Beams 

According to Section 8.4.1.8 of the ACI 318-14 Code, the flange width of 

beam section equals to the web width adds to an offset of slab equals to the 

minimum of (ℎ𝑤 , 4ℎ𝑠) on each side of the beam as shown in Figure 3.5. 

 

Figure 3.5: Part of slab to be considered with internal and edge beams 

Thus, the added extension to the width of the principal rectangular beam is 

the minimum of (ℎ𝑤 = 320𝑚𝑚, 4ℎ𝑠 = 520𝑚𝑚) = 320𝑚𝑚. The cross-

sections of internal and edge beams are shown in Figure 3.6.  

 

Figure 3.6: Cross-sections of internal and edge beams in Model 3N-SR 

Effective Sections of Slabs 

The width of the effective section of slabs (𝑏𝑠) is calculated as:  

𝑏𝑠 = 6000 2⁄ + 6000 2⁄ = 6000𝑚𝑚…𝑎𝑙𝑜𝑛𝑔 𝑡ℎ𝑒 𝑖𝑛𝑡𝑒𝑟𝑛𝑎𝑙 𝑎𝑥𝑒𝑠. 

𝑏𝑠 = 6000 2⁄ + 700 2⁄ = 3350𝑚𝑚…𝑎𝑙𝑜𝑛𝑔 𝑡ℎ𝑒 𝑒𝑑𝑔𝑒 𝑎𝑥𝑒𝑠.  



43 

Flexural Stiffness of Beams and Adjacent Slabs 

Table 3.3 indicates the values of the relative flexural stiffness of internal and 

edge beams.  

Table 3.3: Relative flexural stiffness of internal and edge beams 

 

Slab Thickness 

Table 3.4 shows the calculation steps needed to determine the thickness of 

the slab.  

Table 3.4: The average value of the relative flexural stiffness of beams  

 

7.12E+09

1.10E+09

6.47

6.32E+09

6.13E+08

10.3

𝐼𝑛𝑡𝑒𝑟𝑛𝑎𝑙 𝐵𝑒𝑎𝑚 𝐼𝑏(𝑚𝑚
 )

𝐼𝑛𝑡𝑒𝑟𝑛𝑎𝑙 𝑆𝑙𝑎𝑏 𝑃𝑎𝑛𝑒𝑙 𝐼𝑠(𝑚𝑚
 )

𝐸𝑑𝑔𝑒 𝐵𝑒𝑎𝑚 𝛼𝑓

𝐼𝑛𝑡𝑒𝑟𝑛𝑎𝑙 𝐵𝑒𝑎𝑚 𝛼𝑓

𝐸𝑑𝑔𝑒 𝐵𝑒𝑎𝑚 𝐼𝑏(𝑚𝑚
 )

𝐸𝑑𝑔𝑒 𝑆𝑙𝑎𝑏 𝑃𝑎𝑛𝑒𝑙 𝐼𝑠(𝑚𝑚
 )

Panel* Corner  Edge Internal

5300 5300 5300

5300 5300 5300

5300 5300 5300

1 1 1

8.39 7.43 6.47

𝑙𝑛1 (𝑚𝑚)

𝑙𝑛2 (𝑚𝑚)

𝛼𝑓𝑚

𝑙𝑛  𝑀𝑎𝑥𝑖𝑚𝑢𝑚 𝑐𝑙𝑒𝑎𝑟 𝑠 𝑎𝑛 𝑙𝑒𝑛𝑔𝑡ℎ 

𝛽  𝑅𝑎𝑡𝑖𝑜 𝑜𝑓 𝑙𝑜𝑛𝑔 𝑡𝑜 𝑠ℎ𝑜𝑟𝑡 𝑐𝑙𝑒𝑎𝑟 𝑠 𝑎𝑛 𝑙𝑒𝑛𝑔𝑡ℎ𝑠 

𝛽

𝑙𝑛  𝑚𝑚

* 𝑙𝑛1  𝐶𝑙𝑒𝑎𝑟 𝑠 𝑎𝑛 𝑙𝑒𝑛𝑔𝑡ℎ 𝑖𝑛 𝑑𝑖𝑟𝑒𝑐𝑡𝑖𝑜𝑛 𝑡ℎ𝑎𝑡 𝑚𝑜𝑚𝑒𝑛𝑡𝑠 𝑎𝑟𝑒 𝑏𝑒𝑖𝑛𝑔 𝑑𝑒𝑡𝑒𝑟𝑚𝑖𝑛𝑒𝑑

𝑙𝑛2  𝐶𝑙𝑒𝑎𝑟 𝑠 𝑎𝑛 𝑙𝑒𝑛𝑔𝑡ℎ 𝑖𝑛 𝑑𝑖𝑟𝑒𝑐𝑡𝑖𝑜𝑛  𝑒𝑟 𝑒𝑛𝑑𝑖𝑐𝑢𝑙𝑎𝑟 𝑡𝑜 𝑙𝑛1 



44 

According to Section 8.3.1.2 of the ACI 318-14 Code, for 𝛼𝑓𝑚 > 2 

then, the minimum slab thickness (ℎ𝑚𝑖𝑛) is the greater of:  

        
𝑙𝑛 (0.8 +

𝑓𝑦
1400)

36 + 9𝛽
                           [3.2a] 

        90𝑚𝑚                                              [3.2b] 

⟹ 𝐸𝑞. [3.2a] =
5300(0.8 + 420 1400⁄ )

36 + 9 × 1
= 130𝑚𝑚. 

⟹ 𝐸𝑞. [3.2b] = 90𝑚𝑚.  

𝑆𝑒𝑙𝑒𝑐𝑡 𝑡ℎ𝑒 𝑚𝑜𝑠𝑡 𝑐𝑟𝑖𝑡𝑖𝑐𝑎𝑙 𝑐𝑎𝑠𝑒, ℎ𝑚𝑖𝑛 = 130𝑚𝑚. 

∴ 𝑇ℎ𝑒 𝑎𝑐𝑡𝑢𝑎𝑙 𝑠𝑙𝑎𝑏 𝑡ℎ𝑖𝑐𝑘𝑛𝑒𝑠𝑠 𝑜𝑓 130𝑚𝑚 ≥ ℎ𝑚𝑖𝑛 = 130𝑚𝑚 𝑖𝑠 𝑡ℎ𝑢𝑠 𝑂𝐾. 

Surprisingly, minimum slab thickness is 130mm in all of the twelve models. 

Calculation steps of the minimum slab thickness for the remaining models 

are found in Appendix B. 

3.5.2 Estimating of Beams Depths 

Section 9.3.1.1 in the ACI 318-14 Code specifies the minimum beams depth 

to govern deflection. With reference to Figure 3.3, center-to-center span 

length (𝑙) is 6000mm for all spans in every story in Model 3N-SR. 

𝑆𝑒𝑙𝑒𝑐𝑡 𝑡ℎ𝑒 𝑚𝑜𝑠𝑡 𝑐𝑟𝑖𝑡𝑖𝑐𝑎𝑙 𝑐𝑎𝑠𝑒, ℎ𝑚𝑖𝑛 =
𝑙

18.5
 =
6000

18.5
= 324𝑚𝑚. 

∴ 𝑇ℎ𝑒  𝑟𝑜𝑣𝑖𝑑𝑒𝑑 450𝑚𝑚 𝑑𝑒 𝑡ℎ𝑠 𝑜𝑓 𝑏𝑒𝑎𝑚𝑠 ≥ 324𝑚𝑚 𝑎𝑟𝑒 𝑡ℎ𝑢𝑠 𝑂𝐾. 

The actual beams depths in the remaining models are also found to be 

conservative as shown in Appendix B. 



45 

3.5.3 Estimating of Trial Sections of Columns  

Columns cross-sections have to be determined as for the load effects in the 

lowest story of the building. The tributary area of the most heavily loaded 

column is shown in Figure 3.7. Tables 3.5 and 3.6 give a brief statement of 

the main points required to assess the capacity of column section.  

 

Figure 3.7: Tributary area of an interior column in Model 3N-SR 

Table 3.5: Ultimate self-weights of structural elements included within 

the tributary area  

 

 

Length Width Depth
Slab 1.2 25 6 6 0.13 1

Beams 1.2 25 11.3 0.7 0.45 0.711
Column 1.2 25 3.55 0.7 0.7 0.873

Σ 262
2620

140

* A self-weight multiplier less than 1.0 is applied for beams and columns to ensure that weight is accounted for
only once at shared joints and lines

Load 
Factor

Factored Weights of Elements 
(kN) in the Tributary Area 

Types of Elements in 
the Tributary Area (kN/m3)

Dimensions (m) Mass and 
Weight Modifier*

75.9
45.6

Total ultimate weight of elements (kN) included within the tributary area in 10-stories

𝛾𝑐

𝑀𝑎𝑠𝑠 𝑜𝑟 𝑤𝑒𝑖𝑔ℎ𝑡 𝑚𝑜𝑑𝑖𝑓𝑖𝑒𝑟 𝑜𝑓 𝑏𝑒𝑎𝑚 =
𝑏𝑒𝑎𝑚 𝑑𝑒 𝑡ℎ − 𝑠𝑙𝑎𝑏 𝑑𝑒 𝑡ℎ

𝑏𝑒𝑎𝑚 𝑑𝑒 𝑡ℎ
 

𝑀𝑎𝑠𝑠 𝑜𝑟 𝑤𝑒𝑖𝑔ℎ𝑡 𝑚𝑜𝑑𝑖𝑓𝑖𝑒𝑟 𝑜𝑓 𝑐𝑜𝑙𝑢𝑚𝑛 =
𝑐𝑜𝑙𝑢𝑚𝑛 𝑙𝑒𝑛𝑔𝑡ℎ 𝑠𝑡𝑜𝑟  ℎ𝑒𝑖𝑔ℎ𝑡𝑐 𝑐⁄ − 𝑏𝑒𝑎𝑚 𝑑𝑒 𝑡ℎ

𝑐𝑜𝑙𝑢𝑚𝑛 𝑙𝑒𝑛𝑔𝑡ℎ 𝑠𝑡𝑜𝑟  ℎ𝑒𝑖𝑔ℎ𝑡𝑐 𝑐⁄



46 

Table 3.6: Ultimate weights of distributed loads over the tributary area  

 

Thus, the total factored axial force (𝑃𝑢) = 2620 + 3600 = 6220𝑘𝑁. 

The framing columns could be considerd sidesway inhibited under the 

applied gravity loads. According to Section 6.2.5 of the ACI 318-14 Code, a 

braced column is being short if its slenderness ratio is: 

        
𝑘𝑙𝑢
𝑟
≤ 34 + 12 (

𝑀1
𝑀2
)                    [3.3a] 

        
𝑘𝑙𝑢
𝑟
≤ 40                                          [3.3b] 

Where: 

𝑘 is the effective length factor of the column. 

𝑙𝑢 is the unsupported length of the column. 

𝑟 is the radius of gyration of column cross-section. 

𝑀1 is the smaller factored end moment of the column. 

𝑀2 is the larger factored end moment of the column. 

According to Section R6.2.5 of the ACI 318-14 Code, 𝑘 could be taken equal 

to 1.0. To be more conservative, (𝑀1 𝑀2⁄ ) is assumed to be zero.  

 

Length (m)  Width (m) 
SDL 1.2 3 6 6
LL 1.6 4 6 6

Σ 360
3600

 Load Pattern

Total ultimate weight (kN) over the tributary area in 10-stories

Intensity (kN/m2)
Tributary Area Total Factored Loads (kN) 

on the Tributary Area 
130
230

Load Factor



47 

According to Clause b of Section 6.2.5.1 of the ACI 318-14 Code, 𝑟 could 

be taken as 0.30 times the dimension in the direction stability is being studied 

for rectangular columns. Hence,  

⟹ 𝐸𝑞. [3.3a] =
1 × (3.55 × 0.873)

0.3 × 0.70
= 14 ≤ (34 + 12 × 0 = 34).  

⟹ 𝐸𝑞. [3.3b] =
1 × (3.55 × 0.873)

0.3 × 0.70
= 14 ≤ 40. 

Column slenderness ratio is 14 which is less than 34; short column case. 

Hassoun and Al-Manaseer (2015) stated that the maximum strength of a 

rectangular tied-uniaxial loaded short columns informed in Section 22.4.2.2 

of the ACI 318-14 Code may be taken as: 

        𝑃𝑢 = 0.65 × 0.80 × 𝐴𝑔 × [0.85𝑓𝑐
′ + 𝜌𝑔(𝑓𝑦 − 0.85𝑓𝑐

′)]        [3.4]   

Where: 

𝐴𝑔 is the gross cross-sectional area of the column.  

𝜌𝑔 is ratio of longitudinal steel area to the gross column area.  

𝑓𝑐
′ = 23.5𝑀𝑃𝑎, and 𝑓𝑦 = 420𝑀𝑃𝑎. Using minimum reinforcement ratio in 

columns (𝜌𝑔,𝑚𝑖𝑛) = 1.0% then, 

6220 × 103 = 0.65 × 0.80 × 𝐴𝑔[0.85(23.5) + 0.01(420 − 0.85 × 23.5)] 

⟹ 𝐴𝑔 = 499 × 10
3𝑚𝑚2.  

𝐴𝑠 𝑎 𝑠𝑞𝑢𝑎𝑟𝑒 𝑠𝑒𝑐𝑡𝑖𝑜𝑛, 𝑙𝑒𝑛𝑔𝑡ℎ = 𝑤𝑖𝑑𝑡ℎ = √499 × 103 = 706𝑚𝑚. 

∴ 𝑇ℎ𝑒 𝑎𝑐𝑡𝑢𝑎𝑙 𝑠𝑒𝑐𝑡𝑖𝑜𝑛 𝑑𝑖𝑚𝑒𝑛𝑡𝑖𝑜𝑛𝑠 𝑜𝑓 700𝑚?