Application of UBC and IBC Seismic Codes For R.C. Buildings Design in Sudan

ABSTRACT 

This research dealt with the investigation of possibility of the use of the two representative seismic codes, UBC 1997, and IBC 2006, for seismic force analysis of R.C. buildings in Sudan. The theory of the seismic forces analysis was studied and presented. A R.C. building of eight storeys constructed in two sites, a very low seismic active site and a moderate seismic active site in Sudan which was analyzed by using ETABSv9.7.4 computer program. Utilizing data of the two sites, application of the provisions of each code for each case was conducted. A comparison was made for the provisions of the two codes, and the difficulties of using each code recorded. Then, the results obtained were analyzed, compared and discussed. Based on the comparison recommendations were drawn to which of the codes is a suitable choice for use in Sudan. The study concluded that the IBC 2006 code is more suitable and is to be adopted for use in Sudan.

Contents:

Topic Page

I الآیة

Dedication II

Acknowledgement III

Abstract in English IV

 الدراسة ملخص Abstract in Arabic V

Table of contents VI

List of Tables VII

List of Figures XIII

List of Symbols XV

Chapter One: General introduction 1

1.1 Introductory Remarks 1

1.2 Problem statement 2

1.3 Research Objectives. 2

1.3.1 General Objective 2

1.3.2 Specific Objectives 2

1.4 Research Methodology. 2

1.5 Research Outlines 3

Chapter Two: Literature review 4

2.1 Definitions and the nature of earthquakes 4

2.1.1 Definitions 4

2.1.2 The nature of the earthquake forces 6

2.2 The characteristic and components of earthquake forces 7

2.3 Structural behavior or response due to earthquake forces 10

2.4 Important factors effecting the potential of earthquake damage 11

2.5 The strength of earthquake and intensity 13

2.5.1 The intensity of earthquake 14

2.5.2 The Magnitude of earthquake 15

2.6 The probabilistic seismic hazard of Sudan 16

2.7 Seismicity of Sudan 17

2.7.1 Back ground` 17`

2.7.2 Seism tectonic of Sudan 18

2.7.3 Earthquake catalogue of Sudan 20

2.7.4 Seismic zoning of Sudan 20

Chapter Three: Dynamic Response of Buildings under seismic forces. 24

3.1 Introduction 24

3.2Analysis for seismic forces 24

3.2.1 Dynamic response to earthquake forces 24

3.2.2 Types of dynamic analysis 25

3.2.2.1 Time History dynamic analysis 25

3.2.2.2 Equivalent static lateral forces analysis 26

3.2.2.3The modal method and dynamic response Spectrum analysis 28

3.2.2.4 Using computer programs analysis 40

3.3 Brief description of the two codes [ UBC and IBC ] 41

3.3.1 UBC provisions 41

3.3.1.1 Back ground of UBC 1997. 41

3.3.1.2 Calculation of base shear Vb 42

3.3.1.3 Distribution of lateral forces Fx 47

3.3.1.4 Storey shear forces Vx 48

3.3.1.5 Storey over turning moments Mx 48

3.3.1.6 Lateral displacements 48

3.3.1.7 Interstorey drifts 48

3.3.1.8 Building separations 49

3.3.1.9 Dynamic analysis for UBC 50

3.3.1.10 How to choose the analysis type in UBC 52

3.3.1.11 Diaphragm forces Fxp 54

3.3.2 Seismic IBC provisions 54

3.3.2.1 Background 54

3.3.2.2 Calculation of base shear Vb 56

3.3.2.3 Vertical distribution of seismic forces 68

3.3.2.4 Horizontal distribution of seismic forces 69

3.3.2.5 Torsion including accidental torsion 70

3.3.2.6 Storey over turning moments 71

3.3.2.7 Interstorey drifts 71

3.3.2.8 Structural separation 74

3.3.2.9 P.delta effects 75

3.3.2.10 Simplified lateral load analysis procedure 76

3.3.2.10.1 Base shear 75

3.3.2.10.2 Vertical distribution 78

3.3.2.10.3 Horizontal distribution 78

4.3.11 Modal response spectrum analysis in IBC 78

3.3.2.11.1 Combined response parameters 78

3.3.2.11.2 Horizontal distribution of modal forces 79

3.3.2.12 Diaphragm Design Forces 79

Chapter Four: Dynamic analysis of R.C. building using UBC 1997 and IBC 2006 81

4.1 Introduction 81

4.2 Comparison of UBC 1997 with IBC 2000 Provisions 81

4.3 Application of comparative seismic dynamic analysis of RC. building using ETABS V9.7.4(computer program) with UBC 1997 and IBC 2006 87

4.3.1 Description of the building 87

4.3.2 The loading of the building 87

4.3.3 ETABSv9.7.4 computer program Response Spectrum 89

Analysis

4.4 Analysis of Results 89

Chapter Five: Conclusions and Recommendations 108

5.1 Comments and Conclusions 108

5.2 Recommendations. 110

References: 111

Appendices: 112