Technical Report for A structural Design Project

7/22/2019 Technical Report for A structural Design Project

1/95

AN-NAJAH NATIONAL UNIVERSITY

Technical Report 2Three-Dimensional Analysis and Design of the Gateway Building


2/95

to our parents


3/95

ACKNOWLEDGEMENT

We would like to express sincere heartfelt gratitude to our advisor Dr. Samir H. Helou

for his valuable guidance and advice. He never ceased helping us learn important topicsin the field of Structural Engineering. Dr. Helou has been a great source ofencouragement and motivation as he provided us with his undivided attention andcontinuous support.


4/95

ABSTRACT

The following project aims at providing a state of the art reinforced concrete structuraldesign undertaking of a commercial building situated in the city of Ramallah; it is called

The Gateway Building.

The building is comprised of thirteen stories, of which the three basement levels serve asparking spaces, one basement level is reserved for storage purposes and the rest sevenstories provide office spaces and stores. The upper most two floors are reserved forrestaurants. The three basement levels together have a total area of 4800 square meters;each of the upper floors has an average floor area of about 870 square meters.The loads on each floor will be calculated according to its function. Load values,

combinations and factors will be in compliance with the ACI, the IBC or the UBC.Analysis and design of the structure will be carried out using the Extended ThreeDimensional Analysis of Building Systems Software, ETABS. The slabs design as well asthe foundation design will be carried out using SAFE computer software. Variousroofing schemes are investigated and explored; the most economic one is recommended.Foundation design is an inseparable part of the present design undertaking.


5/95

TABLE OF CONTENTS

CHAPTER I: INTRODUCTION & NUMERICAL MODELING ........................................ 9

1. PURPOSE: .................................................................................................................................................... 9

2. BUILDING INTRODUCTION: .............................................................................................................................. 93. STRUCTURAL TOPOLOGY ............................................................................................................................... 12

3.1 Design Codes ..................................................................................................................................... 12

3.2 Materials Used .................................................................................................................................. 12

3.3 Gravity Loads: .................................................................................................................................... 133.3.1. Dead Loads .............................................................................................................................................. 133.3.2. Snow Loads.............................................................................................................................................. 13

3.4 Load Combinations: ........................................................................................................................... 15

3.5 Soil Conditions: .................................................................................................................................. 15

4. THE MODEL: .............................................................................................................................................. 164.1 Model Geometry: ............................................................................................................................... 16

4.2 The Finite Element Model: ................................................................................................................. 224.2.1. The Frame Element: ................................................................................................................................ 224.2.2. Soil Springs .............................................................................................................................................. 244.2.3. The Shell Element: ................................................................................................................................... 25

4.2.3.1 The Mat Foundation: .................................................................................................................... 27


6/95

3. MODAL ANALYSIS ....................................................................................................................................... 76

4. EQUIVALENT LATERAL LOAD METHOD ............................................................................................................. 77

5. RESPONSE SPECTRUM ANALYSIS ..................................................................................................................... 80

6. LOAD COMBINATIONS .................................................................................................................................. 81

7. RESULTS .................................................................................................................................................... 81

8. STRUCTURAL DESIGN FOR DYNAMIC LOADS ...................................................................................................... 82

8.1 Mat Foundation Design ..................................................................................................................... 82

8.2 Slabs Design ....................................................................................................................................... 848.2.1. Fourth Basement Slab Design.................................................................................................................. 84

CHAPTER IV: STRUCTURAL DESIGN SUMMARY & CONCLUSION.......................... 86

1. STRUCTURAL DESIGN SUMMARY .................................................................................................................... 86

2. CONCLUSION .............................................................................................................................................. 86


7/95

LIST OF TABLES

Table 1: Codes Used for Analysis and Design ...................................................................................... 12Table 2: Materials Used-Concrete........................................................................................................... 12Table 3: Materials Used- Grade 60 Rebar Steel .................................................................................... 12Table 4: Lateral Earth Pressure ............................................................................................................... 13Table 5: ASCE Minimum Design Loads ............................................................................................... 14Table 6: Load Combinations ................................................................................................................... 15Table 7: Cartesian Grid Data ................................................................................................................... 17Table 8: Cylindrical Grid Data ................................................................................................................ 18Table 9: Cylindrical System Origin ......................................................................................................... 18Table 10: Frame element sections used in the model .......................................................................... 23Table 11: Story Data ................................................................................................................................. 31Table 12: Punching shear ratios for all 50 columns in the 4thbasement ........................................... 35Table 13: Punching shear ratios for all 25 columns in the 1st roof ................................................... 37Table 15: Maximum Deflection Values at Selected Floors ................................................................. 38Table 14: ACI TABLE 9.5 (b) of maximum permissible roof deflections ....................................... 38Table 16: "Interior Columns_Large" Auto-Select List ........................................................................ 39Table 17: "Interior Columns_Small" Auto-Select List ........................................................................ 40Table 18: "Exterior Columns' Auto-Select List .................................................................................... 40Table 19: Columns Section Design 46
http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966859http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966859http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966859


8/95

LIST OF FIGURES

Figure 1: The Gateway Building ............................................................................................................... 9Figure 2: Above-grade floors plan .......................................................................................................... 10Figure 3: Basement floor plan ................................................................................................................. 10Figure 4: Elevation view of the building ................................................................................................ 11

Figure 5: Model units and design codes ................................................................................................. 16 Figure 6: Grid Systems ............................................................................................................................. 16Figure 7: Cartesian and Cylindrical Grid Systems ................................................................................ 19Figure 8: Floors Labels ............................................................................................................................. 20Figure 9: Story Data .................................................................................................................................. 21Figure 10: Local coordinate system of the frame element .................................................................. 22Figure 11: Local coordinates of a column section ............................................................................... 23Figure 12: Area spring property data ...................................................................................................... 24

Figure 13: Soil Modulus assignment to shells ....................................................................................... 24Figure 14: Quadrilateral shell element .................................................................................................... 25Figure 15: Shell element uniform coordinate systems ......................................................................... 26Figure 16: 3D view of the mat foundation ............................................................................................ 27Figure 17: Mat foundation section properties....................................................................................... 27Figure 18: 3D screen capture of the walls ............................................................................................. 28
http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966942http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966942http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966943http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966943http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966944http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966944http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966945http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966945http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966946http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966946http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966947http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966947http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966948http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966948http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966949http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966949http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966951http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966951http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966952http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966952http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966953http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966953http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966954http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966954http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966955http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966955http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966956http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966956http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966957http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966957http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966958http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966958http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966959http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966959http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966960http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966959http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966958http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966957http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966956http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966955http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966954http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966953http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966952http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966951http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966949http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966948http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966947http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966946http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966945http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966944http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966943http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966942


9/95

Figure 43: Elevation section of internal wall reinforcement ............................................................... 62Figure 44: Screen capture of design strips menu in SAFE v12 .......................................................... 63

Figure 45: X-axis design strips for 4th

basement slabs ......................................................................... 64Figure 46: CSA_3 moment diagram ....................................................................................................... 64Figure 47: Moment Diagrams for all A-strips in 4th basement slab ................................................. 66Figure 48: Moment Diagrams for all B-strips in 4th basement slab .................................................. 67Figure 49: Design-strip moment diagram with max. values ............................................................... 68Figure 50: Moment diagrams in both A&B strips for 1st-roof slab .................................................. 68Figure 51: Moment diagram of A-strips in mat foundation ............................................................... 72Figure 52: Moment diagrams of B strips in mat foundation .............................................................. 73

Figure 53: Mat foundation detailing preferences .................................................................................. 74Figure 54: Seismic zone factor map ....................................................................................................... 75Figure 55: Mass source Definition .......................................................................................................... 76Figure 56: Story shears in X-direction due to ELLMX ....................................................................... 79Figure 57: Story shears in Y-direction due to ELLMY ....................................................................... 79Figure 58: Response spectrum curve ..................................................................................................... 80Figure 59: CSA3 moment diagram for Comb8 .................................................................................... 84
http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966984http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966984http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966985http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966985http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966986http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966986http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966986http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966986http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966987http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966987http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966988http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966988http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966989http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966989http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966990http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966990http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966991http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966991http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966992http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966992http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966993http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966993http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966994http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966994http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966995http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966995http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966996http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966996http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966997http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966997http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966998http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966998http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373967000http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373967000http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373967000http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966998http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966997http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966996http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966995http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966994http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966993http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966992http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966991http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966990http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966989http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966988http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966987http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966986http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966985http://c/Users/Muqbel/Desktop/REPORT/Technical%20Report%20Draft%20(6)%204%2012_Dr.%20Samir%20editing%20(1).docx%23_Toc373966984


10/95

CHAPTER I:Introduction & Numerical Modeling

1. Purpose:

The purpose of this Graduation Project Exercise is to analyze and design the structural systemfor a multi-functional building in Ramallah; dubbed the Gateway Building. The 3-D analysis anddesign undertakings are carried out in compliance with the ASCE, ACI and UBC codes of

practice. This is accomplished by the widely used computer software ETABS and SAFE.

2. Building Introduction:

The Gateway Building is a multi-functional building located in the city of Ramallah, Al-IrsalStreet. It is comprised of thirteen stories of which four basement levels serve as parking spaces

and the rest eight floors provide office spaces, stores and restaurants. The total area of thebuilding is about 14,000 square meters. All stories have a height of 3 meters each.

According to floor area and geometry, there are two groups of identical floors; the fourbasement floors and the upper floors.


11/95

Figure 3: Basement floor plan


12/95


13/95

3. Structural Topology

3.1Design Codes

Table 1: Codes Used for Analysis and Design

3.2Materials Used

Concrete

UsageStrength fc

(MPa)Unit Weight

(kN/m3)Modulus of Elasticity

(MPa)

Code Use

ASCE /SEI 7-10 Minimum design loads, minimum sectionrequirements and load combinations.

ACI Code 318-11 Frames and shear wall section design and rebar.

ACI Code 318-08 Slab and mat foundation design using SAFE v12

UBC 97 Earthquake analysis


14/95

3.3Gravity Loads:

3.3.1. Dead Loads

The Dead loads are due to structural elements self weight. This load is computedinternally by the software and included in the analysis. The self-weight multiplier is1, so ETABS calculates the weight of an element by multiplying the materialsdensity by the volume of element.

Lateral earth pressure; this type of load acts on structural elements below theground level; these are the external walls of the 4 basements. Backfill soil isclassified as silty gravels or poorly graded gravel-sand mixes with a design lateralload value of 5.50 kN/m2per one meter of depth. Table (3.2-1, ASCE).

Since ETABS software does not have a linear function for loads varying withdepth, it is decided that maximum earth pressure is calculated at the bottom ofeach basement story and imported to ETABS as uniformly distributed loads overareas.

BasementFloor

Depth belowgrade(m)

Lateral earthpressure(kN/m2)

4th basement 12 66


15/95

Floor FunctionLiveLoad

(kN/m2)

Dead Load(kN/m2)

SuperimposedDead

Load (kN/m2)

SnowLoad

(kN/m2

4thbasement Parking 2.5 Self weight 0 0

3rdbasement Parking 2.5 Self weight 0 0

2ndbasement Parking 2.5 Self weight 0 0

1stbasement Parking 2.5 Self weight 0 0

Ground Floor Store spaces 3.6 Self weight 2 0

Mezzanine Floor Store spaces 3.6 Self weight 2 0

1stfloor Office spaces 2.4 Self weight 2 0

2ndfloor Office spaces 2.4 Self weight 2 03rdfloor Office spaces 2.4 Self weight 2 0

4thfloor Office spaces 2.4 Self weight 2 0

5thfloor Office spaces 2.4 Self weight 2 0

1stroof floor Restaurants 4.8 Self weight 2 0

2ndroof floor Restaurants 4.8 Self weight 0 2

Staircase floor Staircase 1 Self weight 0 2

Table 5: ASCE Minimum Design Loads


16/95

3.4Load Combinations:

For the analysis and design of the Gateway Building, gravity static loads areconsidered; the ASCE 7-5 in Chapter 2 recommends the use of the following loadcombinations for the strength design method:

Comb1: U= 1.4D

Comb2: U=1.2D + 1.6L

Comb3: U=1.2D + 1.6L + 0.5S

Comb4: U=1.2D+1.6L+ 0.5S+1.6H

Comb5: U=Envelope (Comb1, Comb2, Comb3, Comb4)

Table 6: Load Combinations

3.5Soil Conditions:

The Structure is built on rock that has a bearing capacity of 250 kN/m2. Duringanalysis and design the soil is treated as a linear and elastic material which means themodulus of sub-grade soil is constant.


17/95

4.The Model:

Numerical Modeling is the basis for modern structural analysis and design. The modelhas to simulate the expected behavior of all elements within the structure.

4.1Model Geometry:

Model geometry is created in partial conformity with the architectural plans of thebuilding. A more challenging structural system necessitated the elimination of some

columns that are deemed superfluous; this resulted in longer span lengths at somelocations.

Model geometry creation steps:

Metric SI standard units are used. All geometric dimensions are in meter units.Design code preferences are also selected


18/95

G1- Cartesian Grid Data

X Grid data Y Grid Data

Grid ID X Ordinate (cm) Grid ID Y Ordinate (cm)

A 0 1 574.2

B 1442.6 2 1204.2

C 1912.6 3 2584.2

D 2758.8 4 3326

E 3301.2 5 3461.4

F 3886.7 - -

G 4526.2 - -

H 5100.4 - -

I 5411.4 - -

Secondary Grid Lines


19/95

Cylindrical Grid Data

Radial Grid Data

Grid ID R Ordinate (cm)

A0

B574.2

Tangential Grid data

Grid ID T Ordinate (cm)

10 09 108 20

7 306 40

5 504 60

3 702 801 90


20/95


21/95

Stories are defined in ETABS from bottom to top, keeping in mind that ETABSlabels floors according to their ceiling, i.e. B4 slab is the top of the 4th basementfloor and the ground slab for the 3rd basement floor and so on. Height of each storyis assigned as well.


22/95

Floor NameHeight(mm)

Elevation(mm)

Stair Case 3000 42000

Roof2 3000 39000

Roof1 3000 36000

F5 3000 33000

F4 3000 30000

F3 3000 27000

F2 3000 24000F1 3000 21000

MEZZANINE 3000 18000

GF 3000 15000B1 3000 12000

B2 3000 9000

B3 3000 6000

B4 3000 3000

Base 0 0

Figure 9: Story Data


23/95

4.2The Finite Element Model:

All structural elements in the model are either frame or shells elements. The task is toselect the element type that would simulate the real behavior of the structure. The three-dimensional model consists of a large number of finite-elements connected together atthe nodes.

The following are the element types used in the numerical model:

4.2.1. The Frame Element:

The frame element is modeled as a straight line connecting two points. Thiselement activates six degrees of freedom at both of its joints (three translationaland three rotational) and include the effects of biaxial bending, torsion, axialdeformation and biaxial shear deformations.

A frame element has its own local coordinate system. The axes of this localsystem are denoted by 1, 2 and 3. The 1 axis is directed along the length of theelement, the 2 & 3 axes lie in the plane perpendicular to the element.Understanding the local coordinate system is essential since it is the basis of loadassignment and reading analysis results.


24/95

ETABS reports internal forces in frame elements as follows:

P, the axial force.V2, the shear force in the 1-2 plane.V3, the shear force in the 1-3 plane.T, the axial torque.M2, the bending moment in the 1-3 plane (about the 2-axis).M3, the bending moment in the 1-2 plane (about the 3 axis)

All frame elements used in the model are prismatic and have square sections. All columnsupports at the bottom of the lower basement level are pinned.

Frame element sections used in the model

Section Depth (mm) Width (mm) Material

C70x70 700 700 Concrete_35MPa

C40X40 400 400 Concrete_35MPa

Table 10: Frame element sections used in the model

The figure below shows local axes of a typical column in ETABS, where the width isalong the 3-axis and the depth is along the 2-axis.


25/95

4.2.2. Soil Springs

The soil supporting the structure is assumed to be linear and elastic with constant sub-grade modulus of (40 * safety factor * soil allowable pressure). Soil springs are assignedas area springs with stiffness equal to sub-grade modulus in the Z-direction and zerostiffness in the other two directions.


26/95

4.2.3. The Shell Element:

The shell element is a three- or four-node element that combines bothmembrane and plate-bending behavior. The major advantage of using the shellelement in this model is that it does not have to be planar, thus it can be used tomodel inclined ramps and stairs. Shell elements in the model are uniformly-loaded in gravity and normal-to-plane directions.

Both quadrilateral and triangular elements are used in the model, but the majority

of shell elements are of a quadrilateral shape. Triangular elements are used incorners and irregular locations where the quadrilateral element could not be used.

The shell element has its own local coordinate system. The axes of this localsystem are denoted 1, 2 and 3. The 1 & 2 axes lie in the plane of the elementand the 3-axis is normal to the plane. The shell element always activates all sixdegrees of freedom at each of its connected joints (Ux, Uy, Uz, Rx, Ryand Rz).


27/95

All shell elements used in the model are thin-shells which means that sheardeformations are neglected. Local axes of area elements are meant to be uniform (allpointing towards one direction); this facilitates retrieving analysis results and assigningloads.


28/95

Shell elements are used in the model for the following structural systems:

4.2.3.1 The Mat Foundation:

A mat foundation of 25 cm thickness is spread under the entire building; underneathcolumns there is additional thickness (drop panels) extruding 35 cm below the matfoundation. Concrete of 35 MPa compressive strength is used for the foundations.


29/95

4.2.3.2 The Walls:

Walls of 30 cm thickness are constructed in the outer perimeter of the building where theyact as retaining walls. Interior walls are of 20cm thickness acting as shear walls and elevatorcores. All walls are defined as shell elements. All wall supports at the bottom of the lowerbasement level were idealized as pinned connections. Windows and doors are assigned aswall openings.


30/95

4.2.3.3Ramps:

Ramps are used in basement parking levels, so the model includes four ramps. They aremodeled as shell elements with a thickness of 25cm. Rampsmeshing is made with addedaccuracy so that the nodes on the ramp are adequately connected with the shear wallssurrounding it. The modeling choice is made since there will be ample steel anchoragebetween the ramps and the walls; concrete is cast simultaneously for ramps and the adjacentparts of the walls.


31/95

4.2.3.4 Stair Cases:

The stair slabs are modeled as shell elements having a thickness of 20 cm. The stairsslabsare connected with the floor slabs in the model with no connection to the shear walls.


32/95

4.2.3.5 Slabs:

Slabs of 25 cm thickness are defined as shell elements; they are used in the model for allfloor levels.


33/95

4.2.4. Model Creation Procedure

The finite elements comprising the structure are interconnected with high accuracy andprecision starting from base to top floor level.

The 13-floors could be all replicated at once, but this is not a convenient act since errorsin the model are almost inevitable, therefore once a certain storey is ready it is preferredto carry out a Model Check which will check area overlaps and other types of errors in

the model. When a Model Check indicates errors, it is the designers job to locate theerrors and fix them before trying to perform a Model Run, taking into considerationthat a no-error-message that the check process shows does not necessarily indicatethat the model will be error-free after performing the Model Run. In conclusion,carrying out a Model Run upon the completion of each individua l story is the properway to smoothen the process of locating errors. The Model Run is performed usingthe standard solverat the level of modeling since it reports errors in the model and locatesthem.


34/95

Most types of errors that are encountered are the lost digits of accuracy, mostly of 6 or7 digits. The other type of error is the Instability Error which indicates the whole

structure or some elements are instable; this is normally due to lack of boundaryconditions.

After making sure that model is free of any type of error, an equilibrium check is carriedout. A test point load of 100 kN is applied at some point in the model in the threedirections (X, Y and Z) and base reactions are subsequently checked. Results confirm thestate of static equilibrium since base reactions in all directions must equal the appliedpoint loads.

Figure 25: Base Reactions due to a test load

4.2.5. Model Load Assignment

After making sure that the model is free of any type of errors, the loads are assigned


35/95

CHAPTER II:LINEAR STATIC ANALYSIS & DESIGN

1. Preliminary Analysis Results

1.1Punching shear

A thickness of 25cm for the slabs is deemed adequate for resisting punching shear, yet themethod used for the check is simple and does not account for moment effects on thepunching shear stress and assumes a one-way behavior of slabs; a method that is not veryaccurate for buildings.

SAFE V12 software is used for calculating punching shear ratios. Floors from ETABSmodel are exported to SAFE V12 while considering load on the exported floor plus all loadsthat come from upper stories. Punching shear ratio is the quotient of the maximum designshear stress over the concrete shear stress capacity. Ratios with a value of less than one meanthat slab thickness is adequate for resisting punching shear; otherwise, slab thickness must beincreased.

The punching shear ratio check is performed for the mat foundation, 4thbasement and 1st

roof. This selection of floors is based on change in live load values and load from upperstories. 4thbasement has the largest vertical load on columns; mat foundation has the largestvertical load combined with soil stress while the 1stroof has the highest live load value of allfloors.

The following table is the SAFE output for punching shear ratios based on ACI 318 08 code


36/95

2101 45.262 12.042 OK 0.513137 480.402

2102 45.262 5.742 OK 0.466837 444.783

2103 8.41506 5.742 OK 0.764348 702.741

2104 6.867 0 Not Calculated







2111 51.004 5.742 Not Calculated

2112 51.71601 12.042 Not Calculated

2113 52.49017 18.892 Not Calculated

2114 53.27564 25.842 Not Calculated


2116 45.262 33.52765 Not Calculated

2117 38.867 33.721 Not Calculated

2118 33.012 33.89803 Not Calculated

2119 27.588 34.06202 Not Calculated2120 19.126 34.31787 Not Calculated

2121 14.426 34.45998 Not Calculated


2123 3.24655 12.042 Not Calculated

2124 1 54805 5 742 Not Calculated


37/95


38/95

The same procedure is performed for the 1stroof floor where the live load is 4.8 kN/m 2(The largest of all floors).

Point GlobalX(m)

GlobalY(m)

Status Ratio(Unitless)

Vu(kN)

2187 14.426 12.042 Not Calculated

2189 19.126 25.842 OK 0.933907 705.807

2191 19.126 18.892 OK 0.990372 825.109

2193 19.126 12.042 OK 0.953191 783.597


2197 27.588 25.842 OK 0.954601 715.622

2198 27.588 18.892 Failed 1.401612 1246.713

2199 27.588 12.042 Failed 1.495514 1280.51


2203 38.867 12.042 OK 0.964988 1177.222


2207 38.867 18.892 Failed 1.441559 1158.114

2208 45.262 25.842 Not Calculated

2210 45.262 18.892 Not Calculated

2212 45.262 12.042 Not Calculated


2216 8.41506 5.742 Not Calculated

2226 10.11355 12.042 Not Calculated

2249 38 867 25 842 Not Calculated


39/95

1.2Deflection:

Deflection of structural elements in the building is a major concern. Actual deflections in the

building need to be checked against permissible deflection limits in the ACI 318-08 code inorder to judge slab thickness adequacy.

Table 14: ACI TABLE 9.5 (b) of maximum permissible roof deflections


40/95

2. Structural Design for Static Loads

After analysis of the ETABS model has been completed and the preliminary results are quitesatisfying, the design process will be carried out in order to select optimum sectiondimensions and reinforcement ratios for all structural elements in the building.

2.1Concrete Frame Design

This includes the design of both columns and beams in the building. Design is performed incompliance with the ACI-318-11 Code.

2.1.1. Column Design:

Column sections used in the modeling stage are checked again in the design stage inorder to assure their adequacy of resisting applied forces and to select the optimumsection dimensions. ETABS is used for this type of design where all columns in the

model are assigned to an auto-select list where the software is given multiplesections defined by the user; the softwares job is to select the optimum section. Afirst check trial was carried out; it indicated that 70X70cm column section is notadequate at some locations.

Th l li d f h i i l h h l i l


41/95

Small Interior Columns

Section Label Width DepthRadius of Gyration

about weak axis(mm)

C60X60 600 600 173.2

C60X40 600 400 115.5

C40X40 400 400 115.5

Table 17: "Interior Columns_Small" Auto-Select List

Large Exterior Columns

Section Label Width DepthRadius of Gyration

about weak axis(mm)

C40X40 600 600 115.5

C30X30 600 400 86.6

Table 18: "Exterior Columns' Auto-Select List


42/95

41Figure 29: Column Labels


43/95

Column

LabelAuto-select list Group Design Section

C22Interior

Columns_Large

Basements C80X80

GF to F2 C80X80

F3 to F5 C80X80

2 Floors C80X80

Staircase C60X60

C23Interior

Columns_Large

Basements C80X80

GF to F2 C80X80

F3 to F5 C80X80

2 Floors C80X80

Staircase C60X60

Interior

Basements C80X80

GF to F2 C80X80


44/95

Column


C20Interior

Columns_Large

Basements C80X80

GF to F2 C80X80

F3 to F5 C80X80

2 Floors C80X80

Staircase C60X60

C12Interior

Columns_Large

Basements C80X80

GF to F2 C80X80

F3 to F5 C80X80

2 Floors C80X80

C16Interior

Columns_Large

Basements C80X80

GF to F2 C80X80

F3 to F5 C80X80


45/95

C18Interior_Columns

Small2 Floors C60X60

C19Interior_Columns

Small

Basements C60X60

GF to F2 C60X60

F3 to F5 C60XC40

2 Floors C60X60

C7Interior_Columns

Small

Basements C60X60

GF to F2 C60X60

F3 to F5 C60X40

2 Floors C60X40

C8Interior_Columns

Small

Basements C60X60

GF to F2 C60X60

F3 to F5 C60X60

2 R f C60XC40


46/95

Column


C34 External Columns All C30X30













47/95









Table 19: Columns Section Design

Selection of Auto-select lists and column groups take two points into consideration:

optimization (selecting the minimum section that resists applied loads) and convenience

during construction by keeping the number of column sections as minimum and as uniform

as possible.

The table below shows an example of forces in design sections in the 4thbasement level.


48/95

ETABS 2013 Concrete Frame DesignACI 318-11 Column Section Design

Column Element Details (Flexural Details)

Level Element Section ID Combo ID Station Loc Length (mm) LLRF Type

B4 C23 C80x80 Comb5ic(Envelope Static) 0 3000 0.4 Sway Special

Section Properties

b (mm) h (mm) dc (mm) Cover (Torsion) (mm)

800 800 50 17.3

Material Properties

Ec(MPa) f'c(MPa) Lt.Wt Factor (Unitless) fy(MPa) fys(MPa)

27806 35 1 413 413

Design Code Parameters

T CTied CSpiral Vns Vs Vjoint

0.9 0.65 0.75 0.75 0.6 0.85


49/95

ETABS 2013 Concrete Frame DesignACI 318-11 Column Section Design

Column Element Details (Shear Details)

Level Element Section ID Combo ID Station Loc Length (mm) LLRF Type

B4 C23 C80x80 Comb5ic(Envelope Static) 0 3000 0.4 Sway Special

Section Properties

b (mm) h (mm) dc (mm) Cover (Torsion) (mm)

800 800 50 17.3

Material Properties

Ec(MPa) f'c(MPa) Lt.Wt Factor (Unitless) fy(MPa) fys(MPa)

27806 35 1 413 413

Shear Design for Vu2,Vu3

Rebar Av/smm/m

Design VukN

Design PukN

Design MukN-m

VckN

VskN

VnkN

Major Shear(V2) 0 299.8167 11746.2555 -548.6075 1030.5642 0 1030.5642

Minor Shear(V3) 0 98.1831 11746.2555 202.573 1030.5642 0 1030.5642

Design Forces


50/95

Rebar selection rules are provided to the software for detailing.

Figure 30: Column rebar selection rules in ETABS


51/95

Figure 34: C23 design schedule from base to staircase

Fi 33 D i n ti n "C" f C23 l nFigure 32: Design section "E" for C23 column


52/95

2.2Wall Design:

Two groups of walls are used in the model; exterior walls of 30 cm thickness and interiorwalls of 20 cm thickness. The first group of walls mainly resists the lateral earth pressureinduced by the backfill soil; therefore M22 and V23 are the governing forces for design. Thesecond group acts mainly as bearing walls.


53/95


54/95

Figure 36: M22 values for the external basement wall


55/95

Story Pier

Label

Station Design

Type

Edge

Rebar

End

Rebar

Rebar

Spacing

mm

Min.

Reinf.

%

Current

Reinf.

%

Pier Leg

mm

Leg X1

mm

Leg Y1

mm

Leg X2

mm

Leg

Y2

mm

She

Reb

mm2

B1 P30 Top Uniform 12 14 250 0.25 0.31 Top Leg

1

47225 346 48133 769 75

B1 P30 Bottom Uniform 12 14 250 0.25 0.31 Bottom

Leg 1

47225 346 48133 769 75


1

47225 346 48133 769 75


Leg 1

47225 346 48133 769 75


1

47225 346 48133 769 75


Leg 1

47225 346 48133 769 75


1

47225 346 48133 769 75


Leg 1

47225 346 48133 769 75

Table 23: ETABS report for uniform basement wall reinforcement


56/95

For the interior walls, flexure and shear values as well as reinforcement data are reported. The

following figures show M22 and V23 values in an interior wall section where the maximumvalues of forces are found.


57/95

i b i C i L L L L Sh


58/95

Story

Pier

Label StationDesign

Type

Edge

Rebar

End

Rebar

Rebar

Spacing

mm

Min.

Reinf

%

Current

Reinf

%

Pier

Leg

mm

Leg

X1

mm

Leg

Y1

mm

Leg

X2

mm

Leg

Y2

mm

Shear

Rebar

mm2/m

Stair

CaseP20 Top Uniform 12 14 250 0.25 0.67

Top

Leg 1

360

12

2779

2

3601

2

2974

2500

Stair

Case P20 Bottom Uniform 12 14 250 0.25 0.48

Botto

m Leg1

388

67

2681

7

3886

7

2974

2 500

Roof2 P20 Top Uniform 12 14 250 0.25 0.67Top

Leg 1

124

49.7

1354

2

1244

9.7

1554

2500

Roof2 P20 Bottom Uniform 12 14 250 0.25 0.49

Botto

m Leg

1

101

13.6

1204

2

1442

6

1204

2500

Roof1 P20 Top Uniform 12 14 250 0.25 0.67Top

Leg 1

124

49.7

1354

2

1244

9.7

1554

2500

Roof1 P20 Bottom Uniform 12 14 250 0.25 0.49

Botto

m Leg1

124

49.7

1354

2

1244

9.7

1554

2 500

F5 P20 Top Uniform 12 14 250 0.25 0.67Top

Leg 1

124

49.7

1354

2

1244

9.7

1554

2500

F5 P20 Bottom Uniform 12 14 250 0.25 0.49

Botto

m Leg

1

124

49.7

1354

2

1244

9.7

1554

2500


Leg 1

124

49.7

1354

2

1244

9.7

1554

2500


Botto

m Leg1

124

49.7

1354

2

1244

9.7

1554

2 500


Leg 1

124

49.7

1354

2

1244

9.7

1554

2500


Botto

m Leg124

49 7

1354

2

1244

9 7

1554

2500


59/95


Leg 1

124

49.7

1354

2

1244

9.7

1554

2500


Botto

m Leg

1

124

49.7

1354

2

1244

9.7

1554

2500


Leg 1

124

49.7

1354

2

1244

9.7

1554

2500


Botto

m Leg

1

124

49.7

1354

2

1244

9.7

1554

2500

MEZZAN

-INEP20 Top Uniform 12 14 250 0.25 0.67

Top

Leg 1

124

49.7

1354

2

1244

9.7

1554

2500

MEZZAN

-INEP20 Bottom Uniform 12 14 250 0.25 0.49

Botto

m Leg

1

124

49.7

1354

2

1244

9.7

1554

2500

GF P20 Top Uniform 12 14 250 0.25 0.67Top

Leg 1

124

49.7

1354

2

1244

9.7

1554

2500

GF P20 Bottom Uniform 12 14 250 0.25 0.49

Botto

m Leg

1

124

49.7

1354

2

1244

9.7

1554

2500

B1 P20 Top Uniform 12 14 250 0.25 0.66Top

Leg 1

124

49.7

1354

2

1244

9.7

1554

2500

B1 P20 Bottom Uniform 12 14 250 0.25 0.48

Botto

m Leg

1

124

49.7

1354

2

1244

9.7

1554

2500

Table 24: ETABS report for uniform interior wall reinforcement


60/95

In ETABS, all walls need to be labeled as piers so that the software would be able to providereinforcement detailing values and graphics. Personal preferences for rebar selection are alsoprovided to ETABS.


61/95

Figure 41: 3D view of confined wall reinforcement at corners

`


62/95

d

`


63/95

Figure 43: Elevation section of internal wall reinforcement


64/95

2.3Slab Design:

Each roof is exported to SAFE V12 for design. SAFE designs slabs for flexure andpunching shear in accordance with ACI-318-08. There are two methods for design; a finite-element-based method and a strip-based one. For this project, the strip-based design is usedsince it allows for rebar calculations, while the finite-element-based approach checks rebararea provided by designer against actual stresses in the slab. Moreover, design strips can beused for rebar detailing.

Procedure of slab design is SAFE V12 is outlined below:

Drawing design strips along the X and Y axes. Design strips are called Strip A andStrip B respectively. Strips for each axis are divided into two types; column stripsthat are drawn along column centerlines and middle strips drawn between each tworows of columns (in mid-spans). All strips have a width of 1 meter.


65/95

2.3.1. 4thBasement Slab Design

Flexure and shear values are reported by SAFE. SAFE also provides reinforcement steelin accordance with ACI-318-08 Code. This slab is solid with no drop panels and has athickness of 25cm.

For design strips, MSA stand for middle strip-A and CSA stands for column strip-A.


66/95

Conc Width

m

FTopMoment

kN.m

FTopArea

mm2

FTopAMin

mm2

FBotMoment

kN.m

FBotArea

mm2

FBotAMin

mm2

V Force

kN

VArea

mm2/m

StatusGlobal X

m

Global Y

m

0.5177 -34.4186 491.497 240.933 2.6667 135.259 0 45.157 0 OK 51.71601 12.042

1 -0.1726 374.834 465.396 14.0022 277.36 0 86.941 0 OK 51.004 12.0421 0 146.421 0 35.7218 485.884 465.396 30.496 0 OK 50.262 12.042

1 -127.3975 1669.485 465.396 0.0193 0 0 157.117 861.845 OK 45.262 12.042

1 -60.5339 765.834 465.396 0 0 0 157.117 861.845 OK 44.867 12.042

1 -10.9128 134.806 465.396 1.1423 14.048 0 52.217 0 OK 43.867 12.042

1 0 0 0 9.9952 123.418 465.396 15.758 0 OK 42.867 12.042

1 0 0 0 9.9846 123.286 465.396 11.761 0 OK 41.867 12.042

1 -3.09 38.034 465.396 1.2232 15.043 0 28.424 0 OK 40.867 12.042

1 -36.8601 461.063 465.396 0.0422 0 0 28.424 0 OK 39.867 12.042

1 -357.0576 5161.406 465.396 0 946.911 0 340.187 2820.612 OK 38.867 12.042

1 -82.3367 1053.254 465.396 0 0 0 340.187 2820.612 OK 38.012 12.042

1 -14.5507 180.049 465.396 2.8689 35.309 0 67.778 0 OK 37.012 12.0421 -0.02 0 0 34.8068 434.843 465.396 41.713 0 OK 36.012 12.042

1 0 0 0 57.5723 727.293 465.396 26.256 0 OK 35.012 12.042

1 0 0 0 69.0246 876.982 465.396 13.978 0 OK 34.012 12.042

1 0 0 0 71.0779 904.01 465.396 4.913 0 OK 33.012 12.042

1 0 0 0 69.4167 882.139 465.396 12.769 0 OK 32.588 12.042

1 0 0 0 58.7434 742.518 465.396 24.532 0 OK 31.588 12.042

1 0 0 0 37.6057 470.443 465.396 38.952 0 OK 30.588 12.042

1 -7.3336 90.442 465.396 4.0817 50.263 0 56.092 0 OK 29.588 12.042

1 -66.5377 844.326 465.396 0 0 0 231.155 1212.478 OK 28.588 12.042

1 -265.5921 3801.853 465.396 0 0 0 231.155 1212.478 OK 27.588 12.042

1 -105.2553 1362.75 465.396 0 0 0 163.827 861.845 OK 27.126 12.042

1 -32.4039 404.358 465.396 0.0217 0 0 72.5 0 OK 26.126 12.042

1 -0.4702 5.781 0 10.8523 134.055 465.396 36.255 0 OK 25.126 12.042

1 0 0 0 28.1028 349.968 465.396 20.927 0 OK 24.126 12.042

Table 25: CSA3 forces and reinforcement reported by SAFE in B4 slab


67/95

Figure 47: Moment Diagrams for all A strips in 4th basement slab


68/95

Figure 48: Moment Diagrams for all B-strips in 4th basement slab


69/95

2.3.2. First-Roof Slab Design

The roof slab has a relatively high live load of 4.8 kN/m2; therefore design is expected tobe different. This slab is solid with a thickness of 25cm and having drop panels of 40cmthickness (15cm extrusion below slab surface) as stated earlier in the preliminary design.


70/95

Table 26: Forces and Reinforcement as reported by SAFE for max. design strip in 1st Roof

ConcWidth

m

FTopMoment

kN.m

FTopArea

mm2

FTopAMin

mm2

FBotMoment

kN.m

FBotArea

mm2

FBotAMin

mm2

VForce

kN

VArea

mm2

/m

StatusGlobalX

m

GlobalY

m

1 -265.0206 2107.761 744.634 0 229.749 0 158.399 861.845 OK 27.126 12.042

1 -692.2001 5925.636 744.634 0 201.323 0 510.627 2329.948 OK 27.588 12.042

1 -174.8691 2388.936 465.396 0 220.075 0 510.627 2329.948 OK 28.588 12.042

1 -43.3142 577.721 465.396 0 130.779 0 136.563 0 OK 29.588 12.042

1 -0.0868 125.632 0 35.1028 473.076 465.396 77.354 0 OK 30.588 12.042

1 0 111.039 0 74.6225 979.651 465.396 43.957 0 OK 31.588 12.042

1 0 107.217 0 93.4558 1229.757 465.396 22.479 0 OK 32.588 12.042

1 0 98.449 0 96.4577 1268.027 465.396 8.943 0 OK 33.012 12.042

1 0 97.796 0 93.3042 1224.313 465.396 23.05 0 OK 34.012 12.042

1 0 97.202 0 74.1228 969.458 465.396 44.788 0 OK 35.012 12.042

1 -0.0931 110.065 0 34.046 455.534 465.396 78.841 0 OK 36.012 12.042

1 -46.6357 625.263 465.396 0 147.345 0 146.988 0 OK 37.012 12.042

1 -187.5513 2582.8 465.396 0 366.405 0 605.309 3169.326 OK 38.012 12.042

1 -736.1775 6401.231 744.634 0 374.324 0 605.309 3169.326 OK 38.867 12.042

1 -85.5196 1095.772 465.396 0 0 0 74.946 0 OK 39.867 12.042


71/95

2.4Mat Foundation Design:

This is the structural system used in this project for supporting the building. The use of thistype of foundation reduces the potential of differential settlement. The relation betweenstresses in the mat slab and the downward vertical settlement is defined as the soil sub-grademodulus (K).

An initial check of the model under this service load combination (D+L) resulted in a basereaction of 162,500 kN. With soil capacity of 250kN/m2 the required foundation area is

650m2which is way less than the area of the foundation provided in the model. Modulus ofsub-grade used is K=25000 kN/m3.

Before starting the first run, all points are selected and released in the vertical Z direction,and then soil sub-grade property is applied as area springs. An initial check of punchingshear results for the mat foundation shows that drop panels of 70cm below columns are notadequate for resisting punching shear stress at some locations where shearing stress reachedtwice that of the sections capacity.Depth of drop panel had to be increased to 120cm in

order to resist punching shear stress.

The major concerns when designing foundations are; foundation uplifts and soil allowablepressure. There should be no behavior of uplift in the mat foundation (tension in soil) andthe allowable soil pressure must not be exceeded at any part in the foundation. The


72/95

F6 -32.98

F6 -21.96

F6 -9.09

Area

Surface Pressure

(kN/m2)F9 -20.15

F9 -81.08

F9 -72.42

F9 -18.83

F10 -81.08

F10 -173.56

F10 -162.77

F10 -72.42F11 -173.56

F11 -238.77

F11 -233.9

F11 -162.77

F12 -238.77

F12 -244.54

F12 -237.08

F12 -233.9

F13 -188.48

F13 -178.84

F13 -233.9

F13 -237.08

F14 178 84


73/95

All pressure values have a negative sign which means that soil is subjected to compressiveforces only and no uplift in the foundation. Maximum and minimum absolute pressure valuehighlighted in red is 244.54 kN/m2; it is less than the allowable soil pressure; 250 kN/m2.

The 25 cm mat thickness selected in the ETABS model is not adequate for resisting flexurebecause the required reinforcement exceeded the maximum allowed. Thickness wasincreased to 30 cm and resulted in an acceptable reinforcement ratio.


74/95

Figure 52: Moment diagrams of B strips in mat foundation


75/95

Figure 53: Mat foundation detailing preferences


76/95

CHAPTER III:

EARTHQUAKE ANALYSIS & DESIGN

1. Background

Earthquakes can cause disastrous damage to structures if the forces they induce aresufficiently greater than the capacity of structural elements in the structure. The potentialseismic forces that may hit the Gateway Building should be studied. Behavior of the gravity-loaded structure will be investigated against lateral dynamic forces. Two methods are usedfor calculating seismic forces; the equivalent static lateral load method and the response

spectrum method.For gravity loads, the elevator cores and internal walls in the model act as bearing walls,while walls in the outer perimeter act as bearing walls and resist shear and moment due tolateral earth pressure from soil backfill in the basement levels. Analysis complies with 1997UBC Code.

2. Geology

The Gateway building is located in al-Irsal Street, Ramallah. This zone is classified as 2Awith both the acceleration seismic and the velocity seismic coefficients (Ca and Cv) equalto 0.15 because soil is classified as rock,SB. This is considered a moderate-risk zoneaccording to UBC97.

3 M d l A l i


77/95

3. Modal Analysis

This is a linear analysis that is used to determine the vibration modes of the structure.

These modes are useful to understand the dynamic behavior of the structure and formthe basis of the Response Spectrum Analysis.

The Eigenvector analysis is used to find the modes of The Gateway Building. Thenumber of modes this analysis can provide is equal to the mass degrees of freedomfound in the model, but usually for such buildings the first modes are sufficient.Eigenvector analysis reports values as Eigenvalues. An Eigenvalue is the square of thecircular frequency (

Where K is the stiffness and M is the mass participating in the dynamic analysis,therefore the mass source must be well-defined in order to provide correct dynamicbehavior for the structure.

The mass participating in the dynamic behavior of the structure comprises of self-massof the structure plus superimposed dead load and a portion of live load; 0.3.

Ci l


78/95

ModePeriod

(Seconds)Frequency

(cycle/second)

CircularFrequency(rad/sec)

Eigenvalue(rad2/sec2)

1 1.102 0.907 5.7019 32.5119

2 0.931 1.074 6.748 45.53613 0.511 1.956 12.2874 150.9794

4 0.268 3.736 23.4749 551.07265 0.227 4.408 27.6991 767.2421

6 0.143 6.974 43.82 1920.18967 0.128 7.793 48.9648 2397.5558

8 0.121 8.296 52.1273 2717.25379 0.097 10.301 64.7201 4188.687

10 0.088 11.346 71.2888 5082.093911 0.083 12.116 76.125 5795.0088

12 0.074 13.576 85.2979 7275.734813 0.069 14.469 90.9094 8264.526814 0.065 15.368 96.5631 9324.4252

15 0.063 15.997 100.5101 10102.289716 0.059 16.899 106.1809 11274.3828

17 0.058 17.216 108.1725 11701.2977

18 0.058 17.374 109.1661 11917.242319 0.054 18.58 116.7427 13628.859620 0.053 18.872 118.5737 14059.7315

Table 29: Modal analysis output


79/95

Parameter Value

T (seconds) 1.1

R 4.5

Soil profile type SB

Z 0.15Ca 0.15

Cv 0.15I 1.0

Table 31: Parameters of Equivalent Lateral Load Method

T, structure period in seconds, is determined according to ETABS output for thefirst mode of the structure. The software provided a value of 1.1 seconds.Method A in Section 1630.2.2 in the UBC-97 Code provides an equation toapproximate T.

T= Ct(hn)3/4

Where, Ct= 0.03, a numerical coefficient.h

n

= 137.8 ft, height of the building in feet.

This equation yielded a structure period of 1.2 seconds. This values is not significantlydifferent from the values provided by ETABS.

Z seismic zone factor The UBC 97 Code provides values for Z for all regions in


80/95

Z, seismic zone factor. The UBC-97 Code provides values for Z for all regions inthe world. For this analysis practice, the value of Z is taken from Earth Sciencesand Seismic Engineering Centerat An-Najah University.

Ca, seismic coefficient from Table 16-Q in the UBC Code.

Cv, seismic coefficient from Table 16-R in the UBC Code.

I, Importance factor that depends on occupancy category as in Table 16-K.

Equivalent lateral load is defined as a load pattern in ETABS in both X and Y directions.This resulted in a 4142 kN base shear in the both X and Y-directions. Load patterns aredenoted by ELLMX and ELLMY.

5 Response Spectrum Analysis


81/95

5. Response Spectrum Analysis

Elastic dynamic analysis of a structure utilizes the peak dynamic response of all effective

modes. The response spectrum curve is a plot of period and acceleration based onstatistical data for each location.

For Caand Cvvalues of 0.15 and a damping ratio of 5%, the UBC-97 Code provides aresponse spectrum curve.

0.2

0.25

0.3

0.35

0.4

0.45

Acceleration

Response Spectrum Curve


82/95

6. Load Combinations

Load combinations of static gravity forces are added to dynamic forces.

Comb5: U=Envelope (Comb1, Comb2, Comb3, Comb4)

Comb6: U=1.2D + 1.0L + 1.0S + 1.0H + 1.0E

Comb7: U=1.2D + 1.0L + 1.0S + 1.0H - 1.0E

Comb8: U=Envelope(Comb5, Comb6, Comb7)

Table 33l: Load combinations for earthquake loads

7. Results

All story drifts are below maximum allowable drifts in the UBC-97 Code. Designphilosophy is based on the idea of assuring life safety during earthquakes, therefore,some structural elements may undergo plastic deformations due to seismic forces butthis will not cause threat to the life of the buildings occupants.

8 Structural Design for Dynamic Loads


83/95

8. Structural Design for Dynamic Loads

The main concern is the lateral forces induced to the structure by the earthquakes.

Structural elements that are designed to resist gravity static forces are expected to failunder dynamic loading. Capacity of elements designed in the linear static stage of theproject will be re-evaluated after applying dynamic loads, and necessary changes to theirdesign will be carried out if needed. Design under dynamic loads is compared to designunder static loads.

8.1Mat Foundation Design

The mat foundation is subjected to the summation of all story shears in the building. Soilis assumed to be the same as in the static analysis; linear with modulus of 25,000 kN/m 3.The pressure in any point in the mat foundation must not exceed 250 kN/m2, that is themaximum allowable soil pressure. Tension or uplift forces on the soil are not allowed aswell.

For resisting gravity static forces, a mat foundation thickness of 30cm thickness with120cm drop panels under columns was dubbed adequate. This design is re-evaluatedunder dynamic lateral load.

Th fir t d i n tri l d m d 30 m thi kn d q t f r r i tin fl r nd h r

Section


84/95

Design StripSection

thicknessmm

Max. negative

moment(kN.m)

4613.6221 1200

Max. positivemoment(kN.m)

513.2 600

Max. shear(kN)

3275.746 1200

Table 36: Max. forces in the mat foundation due to dynamic load

The table above reports maximum moment and shear force in the mat foundation slab.The difference between these forces and the forces reported due to static gravity loadsare not significantly different.

8.2Slabs Design


85/95

8.2Slabs Design

Slab thickness and reinforcement ratios adequacy is judged based on dynamic loading.

8.2.1. Fourth Basement Slab Design

The design completed for gravity loads will be checked against dynamic lateral loads.Design strips are defined as stated earlier.

SAFE V12 has shown that the thickness of 25cm is adequate and is able to resist thelateral load.

M l d C b8 i ifi l diff f h d C b5

Figure 59: CSA3 moment diagram for Comb8


86/95

After adding drop panels, all punching shear ratios were below 1.

Point Global X Global Y Status Ratio VU

2088 19.126 25.842 OK 0.51545 588.531

2089 19.126 18.892 OK 0.387563 414.934

2090 19.126 12.042 OK 0.392851 388.707

2091 19.126 5.742 OK 0.642104 682.224

2092 27.588 25.842 OK 0.662842 633.553

2093 27.588 18.892 OK 0.464407 727.141

2094 27.588 12.042 OK 0.472063 707.536

2095 27.588 5.742 OK 0.533066 788.7092096 38.867 12.042 OK 0.684385 596.694

2097 38.867 5.742 OK 0.742246 686.242

2098 38.867 18.892 OK 0.63552 609.602

2099 45.262 25.842 OK 0.721301 846.306

Table 38: Punching shear data for 4th basement slab with drop panels

Reinforcement details for the 4thbasement slab are shown in the appendix.

CHAPTER IV:Structural Design Summary & Conclusion


87/95

g y

1. Structural Design Summary

Analysis via a numerical model and the application of reinforced-concrete designprinciples that comply with the ACI-318-11 Code have resulted in a section of 60-cmdepth with 120-cm drop panels below columns for punching-shear resistance. As forcolumns, the largest section is square-shaped with 80-cm side length, and the smallestsection is also a square with 30-cm length. Exterior walls that resist the seismic lateral

forces as well as gravity forces have a 30-cm thick section with reinforcement ratios 3times greater than the minimum ratio advised by the code. Interior walls have a sectionof 20-cm. For slabs, all floors have slabs with 25-cm thickness with drop panelsprotruding 15-cm below slab (total thickness of 40-cm) for resisting punching shearforces.

2. Conclusion

This project group has come up with many conclusions regarding analysis and reinforcedconcrete design. Conclusions are summed as follows:

Flat plate slab systems are very efficient and can be used for relatively long spans in


88/95

APPENDIX

Reinforcement Detailing


89/95


90/95


91/95


92/95


93/95


94/95


95/95

Documents

Technical Report for A structural Design Project