building structure design - graduation project
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Structural Design of High-Rise Reinforced Concrete Structure
A project report submitted as a partial fulfilment of B.SC. Degree in civil engineering
By :
Emad Ibrahim Thabet 17810
Mohamed Hamed El-Orfi 17848
Milad Adel Hawiwo 17935
Supervised By :
Mr. Moneer Bhih
Benghazi University | Faculty of Engineering
Civil Engineering Department
I
Acknowledgement
This project could only be planned and written
with the support, encouragement, and tangible
contributions of many people; therefore, it is a
privilege to acknowledge the assistance of others in
its preparation.
First and foremost, we thank Allah for endowing
us with health, patience, and motivation to complete
this work.
We would like to thank our parents who have
made this work possible; we extend our heartfelt
thanks to all who played a role in helping us bring this
project to a successful conclusion.
In particular, we gratefully acknowledge our
supervisor Mr. Moneer Bhih whom we truly appreciate
his willingness to provide valuable assistance and
superb guidance throughout this project.
II
Abstract
In this project we have the enthusiasm for designing a multi-story
building for (Project work – CE452) to get the bachelor's degree in Civil
Engineering, this project represents the result of a long process of
academic education on multiple related courses during our study period
in civil engineering department.
A 23 story Hotel located in Benghazi city is structurally designed in
accordance to ACI 318-11, one floor system is chosen to be adopted by a
comparison between a number of probable floor systems.
STAAD PRO software is used to perform analysis, while design and
detailing procedures are implemented manually.
Floor system and lateral load resisting system are designed in addition to
substructure system; both cross section dimensions and rebar details are
prepared.
III
Table of Contents
List of Tables ..................................................................................... VI
List of Figures ................................................................................... VII
Abbreviations & Notations .............................................................. IX
Part 1 | General Approach ............................................................................. 1
Chapter 1 | Introduction ..................................................................... 2
1.1 Introduction ......................................................................... 2
1.2 Scope of Work ..................................................................... 3
1.3 Building Description ........................................................... 4
Chapter 2 | Design Approach ............................................................. 6
2.1 Introcution ........................................................................... 6
2.2 Consulted Codes .................................................................. 6
2.3 Design Method .................................................................... 6
2.4 Software ............................................................................... 8
Part 2 | Analysis .............................................................................................. 9
Chapter 3 : Loads ............................................................................. 10
3.1 Introduction ...................................................................... 10
3.2 Gravity Loads .................................................................... 10
3.2.1 Dead load : ........................................................................... 10
3.2.2 Live load : .............................................................................. 13
3.3 Lateral Loads .................................................................... 14
3.3.1 Wind Load : ......................................................................... 14
3.3.2 Seismic Load : ..................................................................... 21
Chapter 4 | Modeling ....................................................................... 27
4.1 Introduction ...................................................................... 27
4.2 Modeling Procedure ........................................................ 27
4.2.1Generation of Seismic and Wind Loads ...................... 29
4.3 Syntax Sample for STAAD Pro Model (STAAD EDITOR) 31
Part 3 | Structural Design ........................................................................... 37
IV
Chapter 5 | Design of Floor System and Stairs .............................. 38
5.1 Introduction ...................................................................... 38
5.2 Floor System Design ........................................................ 38
5.2.1 Considerations During Analysis and Design: ........... 38
5.2.2 Design Procedures for typical floor systems members: ........................................................................................ 39
5.2.3 Options for Floor Systems : ............................................ 43
5.2.4 Selected System ................................................................. 52
5.3 Design of All Floors .......................................................... 53
5.3.1 Calculation Sample for Beams and Ribs : .................. 54
5.3.2 Beams and Ribs Design Results .................................... 63
5.3.3 Control of Deflection ........................................................ 68
5.3.4 Design of Slabs : ................................................................. 70
5.3.5 Typical Detailing : .............................................................. 74
5.4 Design of Stairs ................................................................. 79
5.4.1 Stairs Specification : .......................................................... 79
5.4.2 Stairs Design : ...................................................................... 80
Chapter 6 | Design of Lateral Loads Resisting System ................. 85
6.1 Introduction ...................................................................... 85
6.2 Design of Columns ........................................................... 85
6.2.1 Design Strategy : ................................................................ 85
6.2.2 Preliminary Dimensions : ................................................ 87
6.2.3 Secondary Dimensions : ................................................. 89
6.2.4 Column Design Sample : ................................................. 90
6.2.5 Columns Final Design and Detailing: ......................... 99
6.3 Design of Shear Wall ...................................................... 103
6.3.1 General Specifications: ................................................. 104
6.3.2 Shear Wall Internal Forces: .......................................... 105
6.3.3 Calculation for (SW1) Sample : .................................. 108
6.3.4 Shear Wall Final Design ................................................ 111
V
6.3.5 Walls Subjected to Axial Tension : ........................... 112
6.2.6 Design of Stairs Walls and Elevator Walls ............. 113
6.4 Design of Coupling Beams ............................................ 116
6.4.1 Preliminary Sections : .................................................... 116
6.4.2 Coupling Beam Design : ............................................... 116
6.4.3 Structural Drawings for Coupling Beams: .............. 119
6.5 Design of Retaining Walls .............................................. 120
6.5.1 Loads on Retaining Walls : ........................................... 121
6.5.2 Design of Retaining Walls : .......................................... 123
6.5.3 Structural Detailing for Retaining Wall : ................. 126
Chapter 7 | Design of Substructure .............................................. 127
7.1 Introduction .................................................................... 127
7.2 Strategy .......................................................................... 127
7.3 Pile Distribution ............................................................. 128
7.4 Cap Thickness Computation ......................................... 128
7.5 Modeling ........................................................................ 130
7.5.1 Loads : ................................................................................. 131
7.6 Pile Design ...................................................................... 132
7.6.1 Soil Parameters : .............................................................. 132
7.6.2 Design Theory : ................................................................ 133
7.6.3 Design Procedure : ......................................................... 133
7.6.4 Differential Settlement Check : .................................. 137
7.6.5 Pile Cap Design : .............................................................. 138
Apendixes ...................................................................................................... a
Appendix 1 | Architectural Drawings ...................................... a
Appendix 2 | Interaction Diagrams .......................................... r
Appendix 3 | Tolerable Differential Settlement ..................... t
Appendix 4 | Excel Sheets Calculations .................................. u
Appendix 5 | Ss , S1 Seismic Parameters ............................... ee
References ....................................................................................................... i
VI
List of Tables
List of Tables
Table No. Description
Table 3.1 Toppings DataTable 3 – 2 C ParametersTable 3 – 3 Pressure Coefficient
Tables 3 – 4( a & b ) Pressure DistributionTable 3 – 5 Vertical Distribution
Table 5 – 1(a) Beam Design Results ( Flat Plate ) Table 5 – 1(b) Slab Design Results ( flat Plate ) Table 5 – 1(c) Shear CheckTable 5 – 2(a) Beam Design Results ( Solid Slab With Beams ) Table 5 – 2(b) Slab Design Results ( Solid Slab With Beams )
Table 5 – 3 Ribs Design ( Waffle Slab ) Table 5 – 4 Comparison Between Floor Systems Table 5 – 5 Beams & Ribs Design Results ( at support ) Table 5 – 6 Beams & Ribs Design Results ( at midspan )
Table 5 – 7(a) Transverse Reinforcement ( Zone 1 ) Table 5 – 7(b) Transverse Reinforcement ( Zone 2 )
Table 5 – 8 Core Slab Design Result Table 5 - 9 Stairs’ ToppingsTable 5- 10 Stairs Reinforcement Details Table 6 - 1 Column Secondary Dimensions
Table 6–2 ( a & b ) Internal forces Column(a & b) Sample Table 6 – 3 Columns Final Design Tables 6 – 4 Shear-Wall Critical Sections
Table 6-5 ( a through c ) Shear-Wall Internal forces Table 6-6 ( a & b ) Shear Wall Final design
Table 6-7 Shear-Walls In Tension Table 7-1 Columns Loads upon Pile cap Table 7-2 Frictional Pile Resisting System Table 7-3 Foundation Design Results
VII
List of Figures
Figure No. Description
Figure 1-1 Front View of the TowersFigure 1-2 Front and Views of ProjectFigure 3-1 Wall details Figure 3-2 Gravity Loads distributionFigure 3-3 5th Floor Horizontal DistributionFigure 4-1 Geometric and Rendered ModelsFigure 4-2 Input Dialogs for wind parametersFigure 4-3 Input Dialogs for wind parametersFigure 4-4 Seismic parameters outputFigure 5-1 Typical Floor 6th floor to 10th floorFigure 5-2 Arrangement of stirrup reinforcement ACI Fig. R11.11.3(d) Figure 5-3 Flat slab with perimeter beamsFigure 5-4 Flat Slab ModelFigure 5-5 Solid slab with beamsFigure 5-6 Solid slab with beams ModelFigure 5-7 Middle Strip and Column strip dimensionsFigure 5-8 Waffle Pans dimensionsFigure 5-9 Waffle Pans Distribution
Figure 5-10 Waffle Figure 5-11 Waffle slab modelFigure 5-12 5th Floor Horizontal DistributionFigure 5-13 Beams and Ribs section detailsFigure 5-14 Slab dimensions for deflection control calculation Figure 5-15 Global moment in X for Inside core slab direction Figure 5-16 Global moment in Y for Inside core slab direction Figure 5-17 Beams and Ribs typical detailingFigure 5-18 Beams and Ribs typical detailingFigure 5-19 Stairs parametersFigure 5-20 Stairs section detailingFigure 6-1 Columns Preliminary dimensionsFigure 6-2 Columns calculated samplesFigure 6-3 Interaction Diagrams PropertiesFigure 6-4 Column dimensions distribution for all elevations (a) Figure 6-4 Column dimensions distribution for all elevations (b) Figure 6-5 Columns cross section details
VIII
Figure 6-6 Columns Splice DetailsFigure 6-7 Shear wall numberingFigure 6-8 Shear wall typical detailingFigure 6-9 Coupling beam rebar
Figure 6-10 Coupling beam cross section detailsFigure 6-11 Retaining walls planFigure 6-12 Retaining wall Figure 6-13 Loads acting over the retaining wall Figure 6-14 Loads acting over the retaining wall Figure 6-15 Bending moment diagrams Figure 6-16 Retaining wall cross section detailingFigure 7-1 Foundation systemFigure 7-2 Piles distribution Figure 7-3 Cap thickness variationFigure 7-4 Foundation Model Figure 7-5 Soil Profile with soil parametersFigure 7-6 Pile resisting mechanismFigure 7-7 Pile resisting mechanismFigure 7-8 Group Pile efficiency determinationFigure 7-9 Differential settlement
Figure 7-10 X-X Direction Moment ResultsFigure 7-11 Y-Y Direction Moment Results
IX
Abbreviations & Notations
Symbol Definition
Cross sectional area of pile base
Area of concrete section resisting shear transfer
Area enclosed by outside perimeter of concrete cross section Gross area of concrete section
Minimum area of longitudinal reinforcement to resist torsion
Area enclosed by centerline of the outermost closed transverse torsional reinforcement
Area of steel reinforcement
Total cross‐sectional area of transverse reinforcement (including crossties)within spacing s and perpendicular to dimension bc
Area of one leg of a closed stirrup resisting torsion within spacing
Area of shear reinforcement within spacing s
Total area of reinforcement in each group of diagonal bars in a diagonally reinforced coupling beam
Dimension of the critical section measured in the direction of the span for which moments are determined
Dimension of the critical section measured in the direction perpendicular to b1
Width of compression face of member
Cross‐sectional dimension of member core measured to the outside edges of the transverse reinforcement composing area
Web width, wall thickness, or diameter of circular section
Horizontal dimension of building measured normal to wind direction
′ Mean hourly wind speed factor Perimeter of critical section for shear in slabs and footings Turbulence intensity factor
. Concrete cover Deflection Amplification Factor
External pressure coefficient to be used in determination of wind loads for buildings
Seismic response coefficient
Undrained shear strength at base of pile
′ Average Undrained shear strength over pile length Vertical distribution factor
A factor to calculate
Spacing between piles
X
Distance from extreme compression fiber to centroid of longitudinal tension/reinforcement, or Pile diameter
Distance from extreme compression fiber to centroid of extreme layer of longitudinal tension steel
Short‐period site coefficient
Specified compressive strength of concrete
. . Factor of safety
, , Portion of the seismic base shear, V, induced at Level i, n, or x, respectively
Specified yield strength of reinforcement Specified yield strength fy of transverse reinforcement Long‐period site coefficient (at 1.0 s‐period)
Gust‐effect factor Peak factor for background response Peak factor for resonant response
Peak factor for wind response
Product of internal pressure coefficient and gust‐effect factor to be used in determination of wind loads for buildings
, The height above the base to Level i or x, respectively The height above the base to Level i or x, respectively
Structural height Importance Factor
Moment of inertia of gross section of beam about centroidal axis
Moment of inertia of gross section of slab about centroidal axis defined for calculating for and
The importance factor
Wind directionality factor
Installation factor from graph
Topographic factor
Integral length scale factor
Web length of wall
Integral length scale of turbulence
Nominal flexural strength at section
Factored moment at section
Fundamental natural frequency
Reduced frequency
Approximate natural frequency
Factored axial force normal to cross section occurring simultaneously with Vu or ; to be taken as positive for compression and negative for tension
Bearing capacity factor
Design pressure to be used in determination of wind loads for
XI
buildings
Perimeter of centerline of outermost closed transverse torsional reinforcement
Nominal axial strength of cross section
Background response factor
Velocity pressure Velocity pressure evaluated at height z = h
Velocity pressure evaluated at height z above ground Allowable pile capacity
Pile base resistance
Pile shaft resistance Velocity pressure for internal pressure determination Response Modification Coefficient
Center to center spacing of items
Mapped MCER, 5 percent damped, spectral response acceleration parameter at a period of 1 s
Design, 5 percent damped, spectral response acceleration parameter at a period of 1 s
Design, 5 percent damped, spectral response acceleration parameter at short periods
The MCER, 5 percent damped, spectral response acceleration parameter at a period of 1
The MCER, 5 percent damped, spectral response acceleration parameter at short periods adjusted for site class effects
Center‐to‐center spacing of transverse reinforcement within the length
Mapped MCER, 5 percent damped, spectral response acceleration parameter at short periods
The fundamental period of the building
Factored torsional moment at section
Approximate fundamental period of the building
Long‐period transition
Basic wind speed Total design lateral force or shear at the base
Nominal shear strength
Factored shear force
Mean hourly wind speed at height z
Nominal shear strength provided by concrete
Nominal shear strength provided by shear reinforcement Effective seismic weight of the building
, , Portion of W that is located at or assigned to Level i, n, or x, respectively
XII
′ Equivalent height of structure
Exposure constant
′ Mean hourly wind‐speed power law exponent
Average value of for all beams on edges of a panel
Ratio of flexural stiffness of shear head arm to that of the surrounding composite slab section
Factor relating depth of equivalent rectangular compressive stress block to neutral axis depth
Factor used to determine the unbalanced moment transferred by flexure at slab‐column connections
Factor used to determine the unbalanced moment transferred by eccentricity of shear at slab‐column connections
Efficiency of group pile
45o for non‐prestressed members
Modification factor reflecting the reduced mechanical properties of lightweight concrete
Ratio of As to (b d)
Ratio of area of distributed longitudinal reinforcement to gross concrete area perpendicular to that reinforcement
Ratio of area of distributed transverse reinforcement to gross concrete area perpendicular to that reinforcement
′ Vertical effective stress at the base of the pile
Factor used to modify development length based on reinforcement coating Serviceability requirement
Factor used to modify development length based on reinforcement size
Tension reinforcement index
System Over strength Factor
∅ Strength reduction factor
∆ Differential Settlement
∈ ′ Integral length scale power law exponent
General Approach | 1 Introduction
Page 1 of 139
Ch.1
Part 1 | General Approach
General Approach | 1 Introduction
Page 2 of 139
Ch.1
Chapter 1 | Introduction
1.1 Introduction
This project aims to design a 23-story high-rise hotel tower in northwest of
Benghazi city - Libya.
The hotel tower is one of three towers with its supplements in Tatweer Multi-
Use Complex Project, the other two high-rise towers are an office tower of 30-
story and an 18-story residential tower.
Figure 1.1 shows an overview of the Tatweer Project.
It covers an area of 80,000 square meters, with a layout on the side of
Benghazi harbor and a spectacular view of the 23 July Lake.
Figure 1-1 Front View of the Towers
General Approach | 1 Introduction
Page 3 of 139
Ch.1
1.2 Scope of Work
The building is designed to withstand all excreted loads (Gravity and Lateral
Loads) to insure the safety of the structure during its life, also other
requirements like appropriateness, economy and structural adequacy are
considered.
Since the adopted concrete structure essentially consists of the most available
structural material in this region, therefore it is economic.
The following procedures present the process of a structural system design, in
these procedures an acceptable system for both strength and serviceability
requirements are developed.
1) Specifying the Structure to be designed.
2) Analyzing Architectural Drawings.
3) Design Approach.
4) Selecting appropriate Structural System and Geometry.
5) Determining the serviceability requirements.
6) Determining the structural loads (Gravity and Lateral Loads).
7) Performing Preliminary Design.
8) Analyze the Super-Structure.
9) Analyze the Sub-Structure.
10) Design Structural Elements (Ultimate Limit State).
11) Check for compliance with Serviceability requirements.
General Approach | 1 Introduction
Page 4 of 139
Ch.1
1.3 Building Description
Building Hotel Tower - Tatweer Multi-Use Complex Project – Benghazi.
Classification High -Rise Building
Description Hotel tower is a five stars hotel with 273 guest rooms,
occasion room, signature restaurants, SPA and retail area, figure (1.2) shows a
front and top views of the project.
Hotel tower has a base elevation of +0.70 m and extends to a height of
+91.70 m.
It has also steel cage system at the top having a total height of 28.10 m.
The structure consisted of 23 stories; the areas vary in different levels.
The maximum floor dimensions of the floors are 63 m x 54 m.
Total Area 26,285 m2
Ground Area 4,008 m2
Rooms Area 11,541 m2
Levels The project elevations related to the following levels :
00.00 Sea surface level
+00.70 Foundation top level
+05.00 Ground level
General Approach | 1 Introduction
Page 5 of 139
Ch.1
Figure 1-2 Front and Views of Project
General Approach | 2 Design Approach
Page 6 of 139
Ch.2
Chapter 2 | Design Approach
2.1 Introcution
This chapter presents the methods and the criteria of design and analysis in addition to the principles in which to satisfy the requirements of the consulted codes.
2.2 Consulted Codes
- ACI 318 M-11 | American Concrete Institute - Building Code
requirements for structural concrete and commentary.
- ACI Detailing Manual-2004 , Details of Concrete
Reinforcement
- ASCE 7-10 | American Society of Civil Engineers - Minimum
Design Loads for Buildings and Other Structures.
2.3 Design Method
Strength Design Method will be used in according to ACI 318-11 section
(8.1.1) which implies that members shall be proportioned for adequate strength
using load factors and strength reduction factors φ , which can be represented
as follows :
Design Strength ≥ Required Strength
φ (Nominal Strength) ≥ U
General Approach | 2 Design Approach
Page 7 of 139
Ch.2
2.3.1 ACI 318-11 Design Requirements:
The Code defines minimum acceptable standards for materials, design, and
construction practice; it also covers the strength evaluation of existing concrete
structures.
a) General Requirements (Sec 1.1.1) : 1) For structural concrete, fc' shall not be less than 17 MPa. 2) No maximum value of fc′ shall apply unless restricted by a specific Code provision.
b) Durability Requirements (Sec 4.1.1) The value of shall be the greatest of the values required by: (a) Sec 1.1.1 (b) for durability in Chapter 4, and (c) for structural strength requirements
And shall apply for mixture proportioning in Sec 5.3 and for evaluation and acceptance of concrete in Sec 5.6.
c) Required strength (Sec 9.2) Required strength U shall be at least equals to the effects of factored
loads in Eq. (9-1) through (9-7)
The effect of one or more loads not acting simultaneously shall be
investigated.
U = 1.4D (9-1) U = 1.2D + 1.6L + 0.5(Lr or S or R) (9-2) U = 1.2D + 1.6(Lr or S or R) + (1.0L or 0.5W) (9-3) U = 1.2D + 1.0W + 1.0L + 0.5(Lr or S or R) (9-4) U = 1.2D + 1.0E + 1.0L + 0.2S (9-5) U = 0.9D + 1.0W (9-6) U = 0.9D + 1.0E (9-7)
General Approach | 2 Design Approach
Page 8 of 139
Ch.2
d) Design strength (Sec 9.3) In terms of flexure, axial load, shear, and torsion, shall be taken as the
nominal strength calculated in accordance with requirements and assumptions of this Code, multiplied by the strength reduction factors φ
Tension-controlled sections (0.90) Compression-controlled sections:
(a) Members with spiral reinforcement (0.75) (b) Other reinforced members (0.65)
Shear and torsion (0.75)
e) Design strength for reinforcement (Sec 9.4) The values of and used in design calculations shall not exceed 55
MPa, except for prestressing steel and for transverse reinforcement in Sec.
10.9.3 and Sec. 21.1.5.4.
f) Control of deflections (Sec 9.5.1) Reinforced concrete members subjected to flexure shall be designed to
have adequate stiffness to limit deflections or any deformations that
adversely affect strength or serviceability of a structure.
2.4 Software
- Structural Analysis & Design | Bentley Staad Pro V8i
This program will be used for structural analysis of the
structure.
- Computer Aided Design | Autodesk AutoCAD
This program will be used for drawing Structural Detailing of
the structural members.
- Microsoft Office Excel :
This program will be used to make design spreadsheets.
Analysis | 3 Loads
Page 9 of 139
Ch.3
Part 2 | Analysis
Analysis | 3 Loads
Page 10 of 139
Ch.3
Chapter 3 : Loads
3.1 Introduction
In this chapter, a list of loads is presented and classified as gravity loads and lateral loads, all loads are calculated either using the data given in the architectural drawings or with using the provisions of ASCE 7-10 Minimum Design Loads for Buildings and Other Structures, the resulted loads shall be established in accordance with the definitions given below and combined with load combination as specified in ACI 318M-11 section 9.2 .
3.2 Gravity Loads
The gravity loads acting on the structure are: 1) Dead loads (Self weight, Wall loads , Finishing materials). 2) Live load (In accordance to ASCE).
3.2.1 Dead load : The super imposed dead loads are essentially constant during the life of the structure and normally consist of the weight of the components considered such as the slabs , beams , columns and walls .
a) Self weight : The weight of the slabs , beams , columns and other structural members will be considered by the analysis program after specifying the cross sections of elements and identifying materials properties .
b) Toppings Topping for the whole structure can be calculated using appendix 1.D and the calculation is shown in the next table :
Analysis | 3 Loads
Page 11 of 139
Ch.3
Table 3 - 1 Toppings Data
Location Tile Type
Tile description
Tile weight
Mortar thickness
Cast stone
weight (kN/m2)
Mortar weight (kN/m2)
Total weight (kN/m2)
Mechanical room F02
surface hardener &
anti-dust concrete coating
Neglected (solvent) 0.07 - 1.48 1.48
Corridor F09 ceramic tile type-2 0.215 0.07 - 1.48 1.7
Car park F01
polyurethane based car
park signage paint
0.003 0.07 - 1.48 1.49
Storage F09 ceramic tile type-2 0.215 0.07 - 1.48 1.7
Masjid F12 roll carpet Neglected 0.07 - 1.48 1.48
Electric room
F02
(surface hardener &
anti-dust concrete coating )
Neglected (solvent)
0.07 - 1.48 1.48
Fire Lobby F11B stone precast - 0.04 0.66 0.848 1.51 Fire stair F11C stone precast - 0.04 0.66 0.848 1.51
All toppings are slightly less than 2kPa , so it is to be uniformed as 2kPa , nonetheless out of core topping has to be increased due to the existence of partitions made of plaster board ( 0.5 kPa ) .
In-Core topping = 2 kPa
Out-Core topping = 2.5 kPa
Analysis | 3 Loads
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Ch.3
c) Wall load :
Fixed walls in the structure appears only inside the core.
It consists of 20 cm of Brick and a ceramic tile wall cladding as shown in Figure 3.1 .
Brickload/m γ thickness ( Equ. 3-1 )
12.5 20 9.81
2.452kNm
Ceramicload 0.215kNm
Wallheight 3.5m
Wallload 0.245 0.215 3.5 9.33kNm
Figure 3.1 | Wall details
Analysis | 3 Loads
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Ch.3
d) Façade load :
Referring to Appendix 1B , Façade consists of two components of significant weight , a stone and a glaze.
Stoneweight/meter γ thickness height ( Equ. 3-2 )
22 0.1745 3.75 14.396kNm
Glazeweight 0.52 3.75 1.5 0.1745 22 1.5 6.928kNm
Averageweightper9meterspan
0.4 7 14.396 1.55 4 6.928 83.26kNm
Façadeloadpermeter 83.269
9.25kNm
3.2.2 Live load : The superimposed life load was determined in accordance to ASCE 7-10. Table 4-1 Minimum Uniformly Distributed Live Loads :
Hotels : L.L. = 1.92 KPa Stairs and exit ways L.L. = 4.79 KPa
Figure 3.2 | Gravity Loads distribution
Analysis | 3 Loads
Page 14 of 139
Ch.3
3.3 Lateral Loads
The lateral loads acting on the structure are: 1) Lateral load induced by wind force. 2) Lateral load induced by seismic force.
3.3.1 Wind Load :
This part applies the determination of MWFRS wind loads on buildings of all
heights using the Directional Procedure.
The effect of wind on a structure depends upon the density and velocity of the
air, the angle of incidence of the wind, the shape and stiffness of the structure,
and the roughness of its surface .
Wind load parameters :
a. Risk Category :
Type III ; Buildings and other structures, the failure of which could pose a
substantial risk to human life .
b. Basic Wind Speed :
The basic wind speed for Benghazi 35 / ( Ref 10 ) .
c. Wind directionality factor :
0.85; for Buildings - Main Wind Force Resisting System) 1
1 ASCE Table 26.6-1
Analysis | 3 Loads
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Ch.3
d. Exposure Categories:
Surface Roughness C ; Open terrain with scattered obstructions
having heights generally less than (9.1 m). This category includes flat
open country and grasslands2
e. Topographic factor 3 :
1
f. Gust Effect Factor 4
To determine the gust effect factor , the structure must be identified as
a rigid or flexible building .
385 ( Equ. 3-3 )
Where :
∑.
(ASCE Equ. 12.8-10 )
Table 3 – 2 Parameters X Y
36 36 1296 36 36 1296 0.4 11.25 2 9 0.4 12 2 9.6
12 12.991 91
119.8 119.81 1
Resulted 0.0247 0.0305
0.0019
4.849
2 ASCE 26.7.3 3 ASCE 26.8 4 ASCE 26.9
Analysis | 3 Loads
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Ch.3
0.0019
4.351
119.8 393.04 Hence :
385√0.0247393.04
0.154
Or
385√0.0305393.04
0.171
Since fundamental natural frequency in both directions are less than 1 Hz , the structure is flexible 5 Thus the gust-effect factor for flexible buildings is calculated as follows 6:
0.925.
. 7 ( Equ. 3-4 )
Where : 3.4
2 ln 3600 .
8 ( Equ. 3-5 )
2 ln 3600 0.171 0.577
2 ln 3600 0.1713.75
5 ASCE 26.2 6 ASCE 26.9.5 7 ASCE Equ. 26.9-10 8 ASCE Equ. 26.9-11
Analysis | 3 Loads
Page 17 of 139
Ch.3
0.53 0.47 9 ( Equ. 3-3 )
Where :
0.02
.
. 10 ( Equ. 3-6 )
11 ( Equ. 3-7 )
∈ 12 ( Equ. 3-8 )
4.57, 152.4 , ∈ 0.2 13
0.6 0.6 91 54.6 14
152.4 . . 214
15 ( Equ. 3-9 )
0.65 , 0.154
0.65 0.6 9110
. 35 29.55
0.171 21429.55
1.238
7.47 1.238
1 10.3 1.2380.117
1 16 ( Equ. 3-10 )
9 ASCE Equ. 26.9-12 10 ASCE Equ. 26.9-13 11 ASCE Equ. 26.9-14 12 (ASCE Equ. 26.9-9) 13 ASCE Table 26.9-1 14 ASCE 26.9.4 15 ASCE Equ. 26.9-16
Analysis | 3 Loads
Page 18 of 139
Ch.3
By Setting
. . .
.2.42 ( Equ. 3-11 )
Hence ;
. .1 . 0.329
By Setting
. . .
.0.958
Thus ; 1
0.9581
2 0.9581 . 0.579
By Setting 15.4
15.4 0.171 36
29.553.21
Thus 1
3.211
2 3.211 . 0.263
.
0.117 0.329 0.579 0.53 0.47 0.263 0.853
.. 17 ( Equ. 3-12 )
1
1 0.63 36 91214
. 0.829
18 ( Equ. 3-13 )
0.2
0.2 10
0.6 910.151
16 ASCE Equ. 26.9-15a 17 ASCE Equ.26.9-8 18 ASCE Equ.26.9-7
Analysis | 3 Loads
Page 19 of 139
Ch.3
Therefore
G 0.9251 1.7 0.151 3.4 0.829 3.5 0.0853
1 1.7 3.4 0.151
0.853
g. Enclosure classification : The building is considered to act as enclosed building
h. Internal pressure coefficient 0.18 19
Wind Load Pressure Computations :
Design wind pressures for the MWFRS of flexible buildings shall be determined as (ASCE 27.4.2) from the following equation
. . . 20 ( Equ. 3-14 )
- External Pressure Coefficient 21
Table 3 - 3 Pressure CoefficientSurface Cp Use with
Windward Wall 0.8 qz
Leeward Wall -0.5 qh
Side Wall -0.17 qh
Velocity Pressure Exposure Coefficients Determination :
0.613 22 ( Equ. 3-15 )
q 0.613 k 1 0.85 35 638.29k
For ; is determined by a linear interpolation for h=Z from values listed in ASCE Table 17.3-1
1.59 1.5391.4 76.2
1.5991.4 91
≫ 1.59
19 ASCE Table 26.11-1 20 ASCE Equ. 27.4-1 21 ASCE Table 27.4-1 22 ASCE Equ. 27.3-1
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So 638.29 1.59 1014.88
By Substituting in Equ. 3-14 :
0.853 1014.88 0.18
0.853 ∓ 182.69 The pressure distribution on the building
Table 3 – 4 (a) Pressure Distribution Surface q (N/m2) Cp Pressure (N/m2)
Leeward Wall 1014.88
- 0.5 - 250.17 - 615.52 Side wall - 0.17 35.51 - 329.84
For the windward Wall pressure at height Z above the ground :
Table 3 – 4 (b) Pressure Distribution
Z Kz Cp qz(N/m2) P+ (N/m2) P- (N/m2) 0.0 0.85 0.8 542.55 552.91 187.56 4.6 0.85 0.8 542.55 552.91 187.56 6.1 0.9 0.8 574.46 574.69 209.33 7.6 0.94 0.8 599.99 592.11 226.76 9.1 0.98 0.8 625.52 609.54 244.18
12.2 1.04 0.8 663.82 635.67 270.31 15.2 1.09 0.8 695.74 657.45 292.09 18.0 1.13 0.8 721.27 674.87 309.51 21.3 1.17 0.8 746.80 692.29 326.94 24.4 1.21 0.8 772.33 709.72 344.36 27.4 1.24 0.8 791.48 722.78 357.43 30.5 1.26 0.8 804.25 731.50 366.14 36.6 1.31 0.8 836.16 753.27 387.92 42.7 1.36 0.8 868.07 775.05 409.70 48.8 1.39 0.8 887.22 788.12 422.76 54.9 1.43 0.8 912.75 805.54 440.19 61.0 1.46 0.8 931.90 818.61 453.25 76.2 1.53 0.8 976.58 849.10 483.74 91.4 1.59 0.8 1014.88 875.23 509.88
106.7 1.64 0.8 1046.80 897.01 531.65 121.9 1.69 0.8 1078.71 918.79 553.43 137.2 1.73 0.8 1104.24 936.21 570.86 152.4 1.77 0.8 1129.77 953.64 588.28
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3.3.2 Seismic Load : Earthquakes loadings on the structure are produced through its interaction with the ground and its response characteristics . These loadings result from the structure’s distortion caused by the ground’s motion and the lateral resistance of the structure, Their magnitude depends on the amount and type of ground accelerations , mass and the stiffness of the structure. The method used to calculate seismic loads is equivalent lateral force procedure As specified in ASCE 7-10 section 12.8 .
Seismic Parameters :
a) Spectral Response Acceleration Parameters :
= 0.514 ( accordance USGS of Ref. 11 ) Appendix 5 S = 0.206 ( accordance USGS of Ref. 11 ) Appendix 5
Site class “D” (accordance geotechnical report of complex area )
= 1.388 from ASCE07-10 Table 11.4-1 = 1.988 from ASCE07-10 Table 11.4-1
. 0.7134 ( Equ. 3-16 )
. 0.4095 ( Equ. 3-17 )
b) Design Spectral Acceleration Parameters:
= 2. /3 = 0.476g ( Equ. 3-18 )
= 2. /3 = 0.273g ( Equ. 3-19 )
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c) Importance factor :
Occupancy Category ” Risk Category “I : Buildings and other structures, the failure of which could pose a substantial risk to human life : I III 23 Importance Factor (I) based on Occupancy Category = 1.25 24
d) Seismic Design Category :
Seismic Design Category : “C” ( 0.33 ≤ SDS ≤ 0.50) ASCE07-05 Table 11.6-1 Seismic Design Category : “D” ( 0.2 ≤ SD1) ASCE07-05 Table 11.6-1
Most severe Category : Seismic Design Category D . e) Design coefficients and Factors :
ASCE07-05 Table 12.2-1 B. Building Frame Systems 4. Special reinforced concrete shear walls Response Modification Coefficient, R = 6.00 System Over strength Factor, Ωo = 2.50 Deflection Amplification Factor, Cd = 5.00
Seismic load Calculation :
25 ( Equ. 3-20 )
26 ( Equ. 3-21 )
0.4766
1.25
0.0992
23 ASCE07-10 Table 1.5-1 24 ASCE07-10 Table 1.5-2 25 ASCE Equ. 12.8-1 26 ASCE Equ. 12.8-2
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Need not to exceed the following :
27 ( Equ. 3-22 )
According to ( ASCE12.8.2.1) an approximate value of the fundamental period for concrete shear wall structures should be calculated as follows:
28 ( Equ. 3-23 )
From ASCE 7-10 Table 12.8-2
For All other structural systems 0.0488, 0.75
Knowing that 91.7 and Sub. in Equ 3-23
0.0488 91.7 . 1.446
Maximum allowable 29
0.273, 1.427 12.8 1
1.446 1.427 2.063
Sub. in Equ. 3-22
0.273
2.063 61.25
0.0275 0.0992, 0.0275
∶
0.044 0.01 30 ( Equ. 3-24 )
0.0262 0.0275
Take 0.0275
27 ASCE Equ. 12.8-3 28 ASCE Equ. 12.8-7 29 ASCE 12.8.2 30 ASCE equ. 12.8-5
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Story Drift Calculation :
Maximum story drift calculated by the program = 12 mm
Amplified story drift ; ∆ / 31 ( Equ. 3-25 )
5 from ASCE Table 12.2-1
∆ 0.012 5 /1.25 0.048
Allowable Story drift ( ASCE Table 12.12-1 )
All other structures with Risk Category III , ∆ 0.015
∆ 0.015 3.75 0.0563 0.048,
Vertical distribution :
Seismic load vertical distribution is calculated using ASCE07-10 equations,
each floor weight is calculated as an effective seismic weight as defined in
ASCE 12.7.2, the same provision states that the effective seismic weight shall
include only the dead load (note that there is no storage area is used in the
tower, an extra 25% percent of the live load is not required in weight
calculation ).
31 ASCE equ. 12.8-15
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a) Seismic load in x direction
F C V 32 ( Equ. 3-26 )
C ∑
33 ( Equ. 3-27 )
K = 1 , for structures having a period of less than 2.5s or more
Base Shear :
0.0275 346559 9530.373
Table 3 – 5 Vertical Distribution
Floor Weight (kN)
Height (m) C F
(kN) 23 4944.958 90.3 446529.71 0.0321 130.00 22 8000 86.55 692400 0.0497 201.58 21 8881.725 82.8 735406.83 0.0528 214.10 20 8881.725 79.05 702100.36 0.0504 204.40 19 11088 75.3 834926.4 0.0599 243.07 18 11988.77 71.55 857796.21 0.0616 249.73 17 13358.83 67.8 905728.4 0.0650 263.68 16 13358.83 64.05 855632.81 0.0614 249.10 15 14373.2 60.3 866704.14 0.0622 252.32 14 14373.2 56.55 812804.63 0.0584 236.63 13 14373.2 52.8 758905.12 0.0545 220.94 12 14373.2 49.05 705005.61 0.0506 205.25 11 14373.2 45.3 651106.1 0.0467 189.56 10 16055.55 41.55 667108.1 0.0479 194.21 9 16055.55 37.8 606899.79 0.0436 176.69 8 16055.55 34.05 546691.48 0.0393 159.16 7 16055.55 30.3 486483.17 0.0349 141.63 6 16055.55 26.55 426274.85 0.0306 124.10 5 16681.33 22.8 380334.32 0.0273 110.73 4 16681.33 19.05 317779.34 0.0228 92.51 3 20294.84 15.3 310511.05 0.0223 90.40 2 20294.84 9.3 188742.01 0.0136 54.95 1 39960.04 4.3 171828.17 0.0123 50.02
Sum 346559 13927699 1
32 ASCE equ. 12.8-11 33 ASCE equ. 12.8-12
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Horizontal distribution :
Horizontal distribution shall be distributed to the various vertical elements of the seismic force-resisting system in the story under consideration based on the relative lateral stiffness of the vertical resisting elements and the diaphragm (ASCE 12.8.4).
Relative lateral stiffness for the structure has been calculated using STAAD PRO V8i software.
Figure 3-3 5th Floor Horizontal Distribution
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Chapter 4 | Modeling
4.1 Introduction
This chapter presents a brief account on the program modeling process
with its precedents including the geometric input and the generation of
loads.
4.2 Modeling Procedure
Modeling procedure started with a geometric drawing using the program of Autodesk AutoCAD, which is next exported to STAAD PRO program changing the Z up to Y up which is the program requirement for proper lateral load generation.
Slabs were modeled as plates with a convenient mesh generation, preliminary dimensions were assigned to each member and support condition was established.
The software of STAAD requires the shear wall to be modeled as a surface element with automatic meshes in order to get the results of in-plane internal stresses of both shear and moment, while other walls which designed as a compression member can be modeled as a regular plate element with manual meshing using the parametric model which is a new meshing option to provide a finite element mesh which both allow to connect the mesh to any attached node and to have the availability to control the element size.
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STAAD houses a PDELTA ANALYSIS facility, a special analysis for the accounting of slenderness effects , this analysis was performed in order to allow the effects of the second order moments to be considered in the analysis .
A new substantially faster analysis engine has been performed with the use of “ Advanced Solver analysis ” , a new feature engine which reduced analysis time 34 for the total structure .
The following figure shows an overview of the Model.
Finally , Results and internal forces of each structural member have been carried out to excel sheets to design them properly.
34 : The executed model had spent 70 hrs. analyzing, while the advanced engine spent 6 hrs
Figure 4-1 Geometric and Rendered Models
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4.2.1Generation of Seismic and Wind Loads
The following figures shows input dialogs for wind and seismic parameters.
Figure 4-2 Input Dialogs for wind parameters
Figure 4-3 Input Dialogs for wind parameters
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The result of the generated seismic load located in STAAD PRO output file is shown in the next figure ( 4-4 )
It can be noticed that the implemented manual seismic parameters calculation including base shear matches the generated by the program, also manual weight calculation is nearly the same.
Figure 4-4 Seismic parameters output
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4.3 Syntax Sample for STAAD Pro Model (STAAD EDITOR)
The following syntax shows the program code and the sequence of processing the input data by the program :
STAAD SPACE DXF IMPORT OF HOTEL MODEL.DXF
START JOB INFORMATION
ENGINEER DATE 22-Oct-13
END JOB INFORMATION
INPUT WIDTH 79 < lines width >
UNIT METER KN
JOINT COORDINATES
2535 79.88 4.125 6.62; < Joint number , x , y , z >
Member incidences
3440 2658 2669; < Member number ,Start node , End node >
Element incidences shell
6979 4823 4824 4687 < Plate number , first node, second node , third node >
Element Property
152 TO 451 Thickness 0.5 < Plate number , thickness >
Supports
5431 To 54651 FIXED < Supported nodes , type of support >
DEFINE MATERIAL START
ISOTROPIC CONCRETE
E 2.17185e+007
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POISSON 0.17
DENSITY 23.5616
ALPHA 1e-005
DAMP 0.05
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
165 To 545 PRIS YD 0.4 ZD 0.35 < members , YD = member height , ZD = member width >
CONSTANTS
MATERIAL CONCRETE ALL
DEFINE REFERENCE LOADS
LOAD R1 LOADTYPE Live TITLE LIVE LOAD
FLOOR LOAD
YRANGE 4.07 4.1 FLOAD -1.92 XRANGE 69.1 99.3 ZRANGE -38.3 15.2 GY
< x ,y & z Ranges , Distributed live load value and direction >
ELEMENT LOAD
105 TO 351 PR GY -1.92 < plates’ numbers , Distributed load value >
LOAD R2 LOADTYPE Dead TITLE TOPPING
FLOOR LOAD
YRANGE 4.07 4.1 FLOAD -1.92 XRANGE 69.1 99.3 ZRANGE -38.3 15.2 GY
< x ,y & z Ranges , Distributed dead load value and direction >
ELEMENT LOAD
100112 TO 101445 PR GY -2 < plates’ numbers, Distributed load value >
LOAD R3 LOADTYPE Dead TITLE SLAB WEIGHT
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FLOOR LOAD
YRANGE 4.0 4.1 FLOAD -1.428 XRANGE 69.1 99.3 ZRANGE -38.3 15.6 GY
< x ,y & z Ranges , Distributed slab load value and direction >
LOAD R4 LOADTYPE Dead TITLE WALL LOAD
MEMBER LOAD
165 To 171 UNI GY -9.3 < Members’ numbers, Uniform wall load value >
LOAD R5 LOADTYPE Dead TITLE SELF
SELFWEIGHT Y -1 LIST 153 to 554 < Weight direction , members’ list >
END DEFINE REFERENCE LOADS
DEFINE IBC 2006 <Seismic Load Generation>
SS 0.514 S1 0.206 I 1.25 RX 5.5 RZ 5.5 SCLASS 4 TL 7 FA 1.4616 FV 2.32 K 0.9 < Seismic Parameters >
SELFWEIGHT 1
REFERENCE LOAD Y
R2 1.0 R3 1.0 R4 1.0
DEFINE WIND LOAD
TYPE 1 <Wind Generation , Windward Direction>
<! STAAD PRO GENERATED DATA DO NOT MODIFY !!!
ASCE-7-2002:PARAMS 35.000 M/SEC 0 2 1 0 0.000 FT 0.000 FT 0.000 FT 1 - 2 90.375 M 36.000 M 36.000 M 0.300 0.010 0 - 0 0 1 0 1.591 1.000 1.150 0.850 0 - 0 0 0 0.845 0.800 0.180
!> END GENERATED DATA BLOCK
INT 0.631733 0.631733 0.718945 0.771161 0.809717 0.840733 0.866899 0.889654 -
0.909864 0.928096 0.94474 0.960079 0.974324 0.987638 1.00015 0.916257 HEIG 0 -
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4.572 11.1722 17.7725 24.3727 30.9729 37.5732 44.1734 50.7736 57.3739 -
63.9741 70.5743 77.1745 83.7748 90.375 90.375
TYPE 2 <Wind Generation , Leeward Direction>
<! STAAD PRO GENERATED DATA DO NOT MODIFY !!!
ASCE-7-2002:PARAMS 35.000 M/SEC 0 2 1 0 0.000 FT 0.000 FT 0.000 FT 1 -
2 90.375 M 36.000 M 36.000 M 0.300 0.010 1 -
0 0 1 0 1.591 1.000 1.150 0.850 0 -
0 0 0 0.845 -0.500 -0.180
!> END GENERATED DATA BLOCK
INT -0.478803 -0.478803 -0.612145 HEIG 0 90.375 90.375
TYPE 3 <Wind Generation , Sideward Direction>
<! STAAD PRO GENERATED DATA DO NOT MODIFY !!!
ASCE-7-2002:PARAMS 35.000 M/SEC 0 2 1 0 0.000 FT 0.000 FT 0.000 FT 1 -
2 90.375 M 36.000 M 36.000 M 0.300 0.010 2 -
0 0 1 0 1.591 1.000 1.150 0.850 0 -
0 0 0 0.845 -0.700 -0.180
!> END GENERATED DATA BLOCK
INT -0.478803 -0.478803 -0.783844 HEIG 0 90.375 90.375
LOAD 1 LOADTYPE Seismic TITLE SEISMIC X DIRECTION
IBC LOAD X 1
LOAD 2 LOADTYPE Seismic TITLE SEISMIC Z DIRECTION
IBC LOAD Z 1
LOAD 3 LOADTYPE Live REDUCIBLE TITLE LIVE LOAD
REFERENCE LOAD
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R1 1.0
LOAD 4 LOADTYPE Dead TITLE DEAD LOADS
REFERENCE LOAD
R2 1.0 R3 1.0 R4 1.0
REFERENCE LOAD
R5 1.0
LOAD 5 LOADTYPE Wind TITLE WIND X DIRECTION
WIND LOAD X 1 TYPE 1
WIND LOAD -X 1 TYPE 2
WIND LOAD -Z -1 TYPE 3
WIND LOAD -Z 1 TYPE 3
LOAD 6 LOADTYPE Wind TITLE WIND Z DIRECTION
WIND LOAD Z 1 TYPE 1
WIND LOAD -Z 1 TYPE 2
WIND LOAD -X -1 TYPE 3
WIND LOAD -X 1 TYPE 3
LOAD COMB 7 1.4D
4 1.4
LOAD COMB 8 1.2D+1.6L
4 1.2 3 1.6
LOAD COMB 9 1.2D+1L+1W(X)
3 1.0 4 1.2 5 1.0
LOAD COMB 10 1.2D+1L+1W(Z)
3 1.0 4 1.2 6 1.0
LOAD COMB 11 1.2D+1L+1E(X)
3 1.0 4 1.2 1 1.0
LOAD COMB 12 1.2D+1L+1E(Z)
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3 1.0 4 1.2 2 1.0
LOAD COMB 13 0.9D+1W(X)
4 0.9 5 1.0
LOAD COMB 14 0.9D+1W(Z)
4 0.9 6 1.0
LOAD COMB 15 0.9D+1E(X)
4 0.9 1 1.0
LOAD COMB 16 0.9D+1E(Z)
2 1.0 4 0.9
PERFORM ANALYSIS
FINISH
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Part 3 | Structural Design
Structural Design | 5 Design of Floor System and Stairs
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Ch.5
Chapter 5 | Design of Floor System and Stairs
5.1 Introduction
In this chapter a gravity load resisting system is managed to be
designed including the stairs, three floor systems are discussed and
one of them is adopted , the elements to be designed for the chosen
floor system are :
1) Design of Beams.
2) Design of Slabs.
3) Design of Stairs.
5.2 Floor System Design
Three types of floor systems are considered and a choice between them is made upon structural design, also ease of construction is taken into account.
These floor systems are:
1) Flat Plate Floor System with Perimeter Beams (Option 1). 2) Solid Slab with Beams (Option 2). 3) Two-Way Joist Floor System (Waffle slab) (Option 3).
5.2.1 Considerations During Analysis and Design:
a) Gravity loads only : Members load , Toppings , Façade load , Live Load and Wall Load.
b) Load Combination : 1.2 D + 1.6 L.
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c) Columns: Square tied column with (h=1000 mm , b=1000m).
d) Floor : Typical floor has been chosen as the most repetitive floor, which is floors from 6th floor to 10th floor.
5.2.2 Design Procedures for typical floor systems members:
Beams, Ribs, Slabs:
Dimensions :
For Beams → In accordance to ACI Table 9.5(a).
For Slabs:→ In accordance to ACI Table 9.5(c).
Flexure:
. . 35 ( Equ. 5-1 )
0.428 . ( Equ. 5-2 )
b ( Equ. 5-3 )
35 ACI 10.5.1 (equ.10-3)
Figure 5-1 Typical Floor 6th floor to 10th
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Where:
1 ( Equ. 5-4 )
.
( Equ. 5-5 )
² ( Equ. 5-6 )
Checking if the section is in the tension controlled zone:
. ( Equ. 5-7 )
( Equ. 5-8 )
0.375 tension controlled zone checked 36
Shear :
Design of the shear reinforcement has been based on the following equation:
37 ( Equ. 5-9 )
Where :
∅ ∅0.17 38 ( Equ. 5-10 )
∅
∅ ( Equ. 5-11 )
36 ACI Fig. R 9.3.2 37 ACI 11.1 (equ.11-1) 38 ACI 11.4.7.9
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Checking for Vsmax:
0.66 39 ( Equ. 5-12 )
Checking for maximum spacing:
S= Avfyd
Vs . 40 41 ( Equ. 5-13 )
And not more than
( if 0.33 ) 42 ( Equ. 5-14 )
For Slab only:
Asprovided AS-T
Asprovided 0.018 b h ( Equ. 5-15 )
Shear in slab (Two way Shear) :
Vc shall be the smallest of : 0.17 1 ′ 43 ( Equ. 5-16 )
0.083 2 ′ 44 ( Equ. 5-17 )
0.33 ′ 45 ( Equ. 5-18 ) check for shear moment transfer:
∅
46 ( Equ. 5-19 )
Where :
= (from punshing) + ′ (from column strip moment)
39 (5.5) ACI 11.4.7.2 40 ACI 11.9.9.1 (equ. 11-29) 41 ACI 11.4.6.3 (equ. 11-3) 42 ACI 11.4.5.3 43 ACI 11.11.2.1 (equ. 11-31) 44 ACI 11.11.2.1 (equ. 11-32) 45 ACI 11.11.2.1 (equ. 11-33) 46 ACI R11.11.7.2
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1 47 ( Equ. 5-20 )
b1 – direction of frame
= b/2 (corner and interior)
2 ∗ 2 ∗ 2 ( Equ. 5-21 )
2 ∗ 1 2 ( Equ. 5-22 )
1 2 ( Equ. 5-23 )
Mn (edge and corner) = Mu(column strip moment)
∅+ vu
∅x- d
2 ( Equ. 5-24 )
0.07 0.5 . ( Equ. 5-25 )
1 ( Equ. 5-26 )
If 0.33 ′ (Ok)
If 0.33 ′
Arrangement of stirrup shear reinforcement for interior column as shown in the following figure :
47 ACI 11.11.7.1 (equ. 11-37)
Figure 5-2 Arrangement of stirrup reinforcement ACI Fig. R11.11.3(d)
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5.2.3 Options for Floor Systems :
Option 1 | Flat Slab Floor with Perimeter Beams Flat slab floor has been found to be economical where the spans are moderate and loads relatively light also minimum construction time and low labor costs result from the very simple formwork.
The smooth underside of the slab can be painted directly and left exposed for ceiling, or it could be plastered.
Figure 5-3 Flat slab with perimeter beams
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The following graph shows Staad pro model for flat slab (Figure 5-4) :
Floor members dimensions (All in mm) :
Beam 1 : h=600 , b=400 Beam 2 : h=500 , b=300 Outer Plate : h=260 Inner Plate : h=150
Analysis results & Design: 1) Beams Design :
Table 5 – 1(a) Beam Design Results ( Flat Plate )
Beams B1 B2
(+) Midspan (-) Support (+) Midspan (-) Support 400 300 600 500
(kN.m) - 260.4 - 137.7 (kN.m) 185.1 - 115.0 -
(kN) 239.4 118.7 Flexure Strength
931.7 1328.5 715.6 863.9 5586.8 5586.8 3417.0 3417.0
Figure 5-4 Flat Slab Model
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722.7 722.7 442.0 442.0 Rein. 5∅16 mm 7∅16 mm 4∅16 mm 5∅16 mm
x/dt check 0.077 (Ok) 0.107 (Ok) 0.100 (Ok) 0.126 (Ok) Shear Strength
Vc 218.0 133.4 Vs 101.1 24.9
Av/s min 0.35 0.26 S-max 4 shear 271 221
S for 4 leg 900 1200 S used (legs, bar) 250 (4 leg ∅10 mm) 200 (4 leg ∅10 mm)
Note : (At face of support) , (At d distance from face of support) 2) Slap Design :
Table 5 – 1(b) Slab Design Results ( flat Plate )
Plates
X Direction Z Direction Column Strip (+)
Column Strip (-)
Middle Strip
(+)
Middle Strip (-)
Column Strip (+)
Column Strip (-)
Middle Strip
(+)
Middle Strip (-)
1000 1000 260 260
(kN.m) - 141.37 - 55.8 - 152.57 - 56.2
(kN.m) 71.0 - 73.6 - 70.5 - 71.8 -
(kN)
Flexure Strength 874.3 1795.2 907.3 682.9 868.0 1947.5 884.5 687.9 5695.0 5695.0 5695.0 5695.0 5695.0 5695.0 5695.0 5695.0 736.7 736.7 736.7 736.7 736.7 736.7 736.7 736.7
Rein. 4∅18 mm/m
8∅18 mm/m
4∅18 mm/m
3∅18 mm/m
4∅18 mm/m
8∅18 mm/m
4∅18 mm/m
3∅18 mm/m
x/dt check 0.08(Ok) 0.15(Ok) 0.08(Ok) 0.06(Ok) 0.08(Ok) 0.15(Ok) 0.08(Ok) 0.06(Ok)
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Table 5 – 1(C) Shear Check (kN) 1064.2
Column type Interior ∅ (kN) 1623.8 > (Ok)
Punching Shear Check Vn (N/mm2) 2.96Vc (N/mm2) 1.95 < 2.96 (Not Ok) , Provide Shear
stirrups Vs (kN) 1.01 N/mm2→ 1300 kN
S for stirrups 100 (4 leg ∅10 mm)
Option 2 | Solid Slab with Beams
Figure 5-5 Solid slab with beams
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Analysis Results: The following graph shows Staad pro model for solid slab with beams (Figure 5-5) :
Floor members dimensions (All in mm) : Beam 1 : h=500 , b=400 Beam 2 : h=500 , b=300 Outer Slab : h=250 Inner Slab : h=150
1) Beams Design :
Table 5 – 2(a) Beam Design Results ( Solid Slab With Beams )
Beams B1 (Outer) B2 (Inner)
Mid span Support Mid span Support 400 300 500 500
(kN.m) - 180.9 - 214.7 (kN.m) 121.7 - 122.0 -
(kN) 143.04 150.9 Flexure Strength
754.6 1139.8 764.8 1394.9 4535.4 4535.4 3401.5 3401.5 586.7 586.7 440.0 440.0
Rein. 3∅20 mm 4∅20 mm 3∅20 mm 5∅20 mm x/dt check 0.09 (Ok) 0.12 (Ok) 0.12 (Ok) 0.20 (Ok)
Figure 5-6 Solid slab with beams Model
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Shear Strength Vc 177.8 133.4 Vs 12.9 67.8
Av/s min 0.35 0.26 S-max 4 shear 221 221
S for 4 leg 900 1200 S used (legs, bar) 250 (4 leg ∅10 mm) 200 (4 leg ∅10 mm)
2) Slab Design :
Table 5 – 2(b) Slab Design Results ( Solid Slab With Beams )
Slab
X Direction Y Direction Column Strip (+)
Column Strip (-)
Middle Strip
(+)
Middle Strip (-)
Column Strip (+)
Column Strip (-)
Middle Strip
(+)
Middle Strip (-)
1000 1000 250 250
(kN.m) - 91.7 - 32.9 - 81.4 - 32.0
(kN.m) 45.9 - 47.1 - 45.8 - 44.2 -
(kN) 61.1
Flexure Strength 581.3 1191.6 596.8 414.3 580.0 1052.7 559.3 402.8 5488.8 5463.1 5488.8 5488.8 5488.8 5463.1 5488.8 5488.8 710.0 706.7 710.0 710.0 710.0 706.7 710.0 710.0
Rein. 5∅14 mm/m
6∅16 mm/m
5∅14 mm/m
5∅14 mm/m
5∅14 mm/m
6∅16 mm/m
5∅14 mm/m
5∅14 mm/m
x/dt check 0.06(Ok) 0.09(Ok) 0.06(Ok) 0.06(Ok) 0.06(Ok) 0.09(Ok) 0.06(Ok) 0.04(Ok)
Shear Strength ∅ (kN) 188.6 > 61.1 kN
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Option 3 | Two-Way Joist Floor System (Waffle slab)
Waffle mould dimension was chosen between multiple available standard
pans as presented in (Ref. 12) , the following graph shows a view for the waffle
slab pans with a (9 m x 9 m) span :
Figure 5-7 Middle Strip and Column strip dimensions
Figure 5-8 Waffle Pans dimensions Figure 5-9 Waffle Pans Distribution
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Analysis Results: The following graph shows Staad pro model for waffle slab (Figure 5-11) :
Figure 5-11 Waffle slab model
Figure 5-10 Waffle
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Floor members dimensions (All in mm) : Beam 1 : h=400 , b=350 , Concrete cover = 40 mm Beam 2 : h=400 , b=450 , Concrete cover = 40 mm Beam 3 : h=400 , b=450 , Concrete cover = 40 mm Rib : h=400 , b=200, Concrete cover = 30 mm
Table 5 – 3 Ribs Design ( Waffle Slab )
Beams B1 B2 B3 Rib
Mid span
Support Mid span
Support Mid span
Support
Mid span Support
350 450 450 200 400 400 400 400
(kN.m) - 158.783 - 270.8 - 150.8 - 109.1
(kN.m) 106.0 - 152.0 - 218.0 - 83.8 -
(kN) 164.8 318.1 218.0 99.2
Flexure Strength 866.8 1337.7 1251.2 2356.3 1848.4 1240.7 866.8 1337.7 3075.6 3075.6 3954.3 3954.3 3954.3 3954.3 3075.6 3075.6 397.8 397.8 511.5 511.5 511.5 511.5 397.8 397.8
Rein. 4∅18 mm
6∅18 mm
5∅18 mm
10∅18 mm
(2 Layers)
5∅18 mm
5∅18 mm
4∅18 mm
(Bundled)
3∅18 mm
x/dt check
0.18(Ok)
0.21(Ok) 0.14(Ok)
0.14(Ok) 0.14(Ok)
0.14(Ok)
0.24(Ok) 0.05(Ok)
Shear Strength Vc 120.4 133.4 154.7 70.8Vs 125.3 290.7 159.7 61.5
Av/s min 0.305 0.262 0.392 0.174S-max for
shear 171 221 171 176
S for 4 leg 1026 1200 800 1800S used (legs, bar)
200 (4 leg ∅10 mm)
250 (4 leg ∅10 mm)
200 (4 leg ∅10 mm)
200 (2 leg ∅10 mm)
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Comparison between floor systems :
Table 5 – 4 Comparison between Floor Systems
Options Floor
Weight (kN)
Estimated Reinforcement
(ton)
Estimated Formwork
(m2)
Pans (Number)
Flat Slab System
17741.64 46.6 1225.8 -
Solid Slab with beams
System 15990.69 35.9 1245.6 -
Waffle Slab System 14885.96 36.5 1110.6 1250
5.2.4 Selected System
Two-Way Joist Floor System (Waffle Slab) has been chosen as the selected floor system , and the following points shows the advantages of using this system :
1) Waffle system is the lightest solution with a significant concrete saving compared to other systems .
2) It is easy to erect specially with the advantage of embedded beams (Flat shuttering is used).
3) Moulds are reusable with up to 120 times ( Ref 12 ) making it cost effective , also it provides an excellent feature finishing.
4) Moulds are lightweight (polypropylene moulds), durable and easy to handle.
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5.3 Design of All Floors
According to 5.1.4 , Waffle slab system is the system used for all floors , the following shows the detailed design for this floor elements.
The following figure shows beams (B1 to B4) distribution :
Figure 5-12 5th Floor Horizontal Distribution
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5.3.1 Calculation Sample for Beams and Ribs :
torsion effect acting simultaneously in the same combination with critical moment or critical shear will be considered
Calculation Sample of (B3) :
420 = 35 Mpa λ = 1
. 40 10
Assume : ∅ 0.9
∅ 0.75
b = 450 mm
h = 400 mm
a) Longitudinal Reinforcement ( at Support ) :
MaximumNegativeM 218.73kN.m, with
54 .
Assume: 20
2
400 40 10 202
340
∅
.
.4.67 ( Equ. 5-27 )
m = fy
0.85fc' =
.= 14.12 ( Equ. 5-28 )
1 1 ( Equ. 5-29 )
114.12
1 1 2 14.12 4.67
420 0.01217
As-req= ρ ×b ×d = 0.01217 450 340 1816.8mm
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As-max 0.428 0.85 fc'
fy×β1 ×b×d ( β1 0.8) 48 ( Equ. 5-29 )
= 0.428 × 0.85 ×35
420 0.8 450 340 = 3710.8 mm2 ( Equ. 5-30 )
.
. 49
0.25√35420
450 340 1.4420
450 340
538.8 governs 510
As-min= 538.8mm2
∶ As-req for flexure 1816.8mm
ℓ
. 50 ( Equ. 5-31 )
0.496, 1300,
. 545 5 42
0.175 0.175 0.1875
ℓ0.42√35 450 400
4200.496 1300
420420
419.68
ℓ cot 51 ( Equ. 5-32 )
Aℓ 0.496 1300420420
cot 45 644.8mm Aℓ
48 ACI 10.2.7.3 49 [ ACI (10.5.1) equation (10.3) ) ] 50 ACI 11.5.5.2 equ. 11-24 (a) 51 ACI 11.5.3.7 equ. 11-22 (a)
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Total longitudinal reinforcement shall be distributed around perimeter of the beam 52
A A Aℓ 1816.8 644.84
1978mm
Use 7 20 1
a= Asfy
0.85 fc'b ( Equ. 5-33 )
a = 2199×420
0.85 × 35 × 350 = 69 mm
xdt
69
0.8 3400.253< 0.375
hence ∅=0.9 tension control checked
S ( Equ. 5-34 )
S 35mm 25 & d , OK 53
b) Longitudinal Reinforcement ( at Mid span ) :
Maximum Positive M 105.1kN.m
Assume: 16
2
400 40 10 162
342
∅
.
.2.22( Equ. 5-35 )
m = fy
0.85fc' =
.= 14.12( Equ. 5-36 )
1 1 ( Equ. 5-37 )
52 ACI 11.5.6.2 53 ACI (7.6.1)
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114.12
1 1 2 14.12 2.22
420 0.0055
As-req= ρ ×b ×d = 0.0055 450 342 846.5mm
As-max 0.428 0.85 fc'
fy×β1 ×b×d ( β1 0.8 54 ( Equ. 5-38 )
= 0.428 × 0.85 ×35
420 0.8 450 342 = 3732.6 mm2
.
. 55
0.25√35420
450 342 1.4420
450 342
542 governs 513
As-min= 542 mm2
∶ As-req for flexure 846.5mm
Use 5 16 1
a= Asfy
0.85 fc'b
a = 1005×420
0.85 × 35 × 450 = 31.54 mm
xdt
31.54
0.8 3400.116< 0.375
hence ∅=0.9 tension control checked
S ( Equ. 5-39 )
S 67.5mm 25 & d , OK 56
54 ACI 10.2.7.3 55 ACI 10.5.1 equation (10.3) 56 ACI 7.6.1
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c) Transverse reinforcement ( Zone 1 ) :
V 258.7kN, withT 54 . , 420 .
T ∅ 0.083 λ √fc′ 57 ( Equ. 5-40 )
T 0.75 × 0.083 × 1 × √35450 4002 450 400
7.019kN.m
T ∅ 0.33 λ √fc′ 58 ( Equ. 5-41 )
T 0.75 × 0.33 × 1 × √35×450 4002 450 400
27.91 .
54 . , 27.91 .
Check section adequacy :
.∅ 0.66 59 ( Equ. 5-42 )
P 2 h 2c. c 2d b 2c. c 2d
2400 2 40 2 10 450 2 40 2 10
1300mm
h 2c. c 2d b 2c. c 2d
400 2 40 2 10 450 2 40 2 10 105000
0.17 ( Equ. 5-43 )
0.17 √35 450 340/1000 153.87
258.7 1000450 340
27.91 1000000 13001.7 105000
0.75 153.87 1000450 340
0.66√35
57 ACI 11.5.1 (a) 58 ACI 11.5.2.2 (a)
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2.57 3.68 (Hence, section is adequate)
∅∅
258.7 0.75 153.87
0.75191.06
0.66 60 ( Equ. 5-43 )
0.66√35 450 340 597.4
0.85 0.85 105000 89250 ( Equ. 5-44 )
45 ( for non-prestressed members )
61 ( Equ. 5-45 )
27.91 10000000.75
2
89250 420 cot 45
0.496
62 ( Equ. 5-46 )
191.06 1000420 340
1.338
Total transverse reinforcement = 1.338 0.496 2
2.33
Assume 4 leg ∅10( A = 314.16 )
s A2.33
314.162.33
134.8mm, 100
Minimum transverse reinforcement :
2 0.062 63 ( Equ. 5-47 )
20.062√35
450420
0.393 2.16
60 ACI 11.4.7.9 61 ACI 11.5.3.6 equ. 11-21 (a) 62 ACI 11.4.7.2 equ. 11-15 (a) 63 ACI 11.5.5.2 equ. 11-23
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Maximum spacing of transverse reinforcement for torsion :
162.5 , 300 64
Maximum spacing of transverse reinforcement for Shear :
0.33 0.33√35 298.7 65
Sd2
3402
170 100 ,
Assume 4 leg ∅10@100 .
d) Transverse reinforcement ( Zone 2 ) :
V 34.12kN,withT 11.6 . , 420 .
T ∅ 0.083 λ √fc′ 66 ( Equ. 5-48 )
T 0.75 × 0.083 × 1 × √35450 4002 450 400
7.019kN.m
T ∅ 0.33 λ √fc′ 67 ( Equ. 5-49 )
T 0.75 × 0.33 × 1 × √35×450 4002 450 400
27.91 .
11.6 . , 11.6 .
Check section adequacy :
.∅ 0.66 68 ( Equ. 5-50 )
P 2 h 2c. c 2d b 2c. c 2d 2400 2 40 2 10 450 2 40 2 10 1300mm
64 ACI 11.5.6.1 65 ACI 11.4.5.3 66 ACI 11.5.1 (a) 67 ACI 11.5.2.2 (a) 68 ACI 11.5.3.1 , Equ. (11-18)
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h 2c. c 2d b 2c. c 2d
400 2 40 2 10 450 2 40 2 10 105000
0.17 ( Equ. 5-51 )
0.17 √35 450 340/1000 153.87
34.12 1000450 340
11.6 1000000 13001.7 105000
0.75 153.87 1000450 340
0.66√35
0.4 3.68 ( Hence section is adequate )
∅∅
34.12 0.75 153.87
0.750,
0.85 0.85 105000 89250
45 ( for non-prestressed members )
69 ( Equ. 5-52 )
11.6 10000000.75
2
89250 420 cot 45
0.206
Total transverse reinforcement = 0 0.206 2
0.412
Assume 4 leg ∅10( A = 314.16 )
s A
0.412314.160.412
762.5mm
Minimum transverse reinforcement:
2 0.062 70 ( Equ. 5-53 )
69 ACI 11.5.3.6 equ. 11-21 (a) 70 ACI 11.5.5.2 equ. 11-23
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20.062√35
450420
0.393 0.412
Use 4 leg ∅10@130 .
Calculation Sample of (B2) :
a) Longitudinal Reinforcement ( at Support ) :
MaximumNegativeM 401.43kN.m, with 3.25 .
Same procedure as in sample calculation of (B3) except No need to add up ℓ to longitudinal reinforcement, because threshold torsion has been exceeded as calculated in transverse reinforcement of Zone 1 .
b) Longitudinal Reinforcement ( at Mid span ) :
Same procedure as in sample calculation of (B3) .
c) Transverse reinforcement ( Zone 1 ) :
V 440.55kN, withT 3.25 . , 420 .
T ∅ 0.083 λ √fc′ 71 ( Equ. 5-54 )
T 0.75 × 0.083 × 1 × √35450 4002 450 400
7.019kN.m
3.25 . thresholdexceeded, designonlyonshear
0.17 0.17 √35 450 340/1000 153.87
∅∅
440.55 0.75 153.87
0.75433.53
0.66 ( Equ. 5-55 )
0.66√35 450 340 597.4
71 ACI 11.5.1 (a)
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72 ( Equ. 5-56 )
.
3.036mm
Assume 4 leg ∅10( A = 314.16 )
s A
3.036314.163.036
103.48mm, 100
Maximum spacing of transverse reinforcement for Shear :
0.33 0.33√35 298.7 73
Sd2
3402
170 100 ,
Assume 4 leg ∅10@100 .
d) Transverse reinforcement ( Zone 2 ) :
Same procedure as calculation of transverse reinforcement of Zone 1.
5.3.2 Beams and Ribs Design Results
a) Longitudinal reinforcement at support :
Table 5 – 5 Beams & Ribs Design Results ( at support ) Member B1 B2 B3 B4 R1
Dimensions
350 400 450 400 450 400 200
400 200 400
c.c. used (mm) 40 40 40 40 30
(kN.m) 290.58 401.43 218.73 41.9 102
(kN.m) 97.65 3.25 54 2.6 4.5
(mm2) 419.1 538.8 538.8 241.6 207.8
(mm2) 3066.5 3931.1 3942.7 1767.8 1520.8
72 ACI 11.4.7.2 equ. 11-15 (a) 73 ACI 11.4.5.3
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(mm2)
2690.3 3759 2025.1 334.7 851.8
ℓ (mm2) 304.23
Not required " less than Threshold
torsion"
419.7 343.8 263.59
ℓ (mm2) 524
Not required " less than Threshold torsion"
645.2 129.5 209.7
ℓ
(mm2) 131
Not required "less than Threshold torsion"
161.3 86 65.9
(mm2) 2821.3 3759 2186.4 420.7 917.8
(mm2)
On 1 layer
b) Longitudinal reinforcement at Mid-span :
Table 5 – 6 Beams & Ribs Design Results ( Midspan ) B1 B2 B3 B4 R1
Dimensions (
350400
450400
450400
200400
200400
c.c. used (mm) 40 40 40 40 30
(kN.m) 131 166.13 105.1 46.73 69.7
420.3 538.8 542 207.8 247.9
3075.6 3942.7 3732.6 1520.4 1814.1
1086.1 1380.6 846.5 394.4 554.7
6 16 On 1 layer
6 18 On 1 layer
5 16 On 1 layer
3 14 On 1 layer
3 16 On 1 layer
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c) Transverse reinforcement (at zone 1) :
Table 5 – 7(a) Transverse Reinforcement ( Zone 1 )
B1 B2 B3 B4 R1 Dimensions
( 350 400 450 400 450 400 200 400 200 400
c.c. used (mm)
40 40 40 40 30
(kN) 219.5 440.55 258.7 75 116.78
(kN.m) 97.65 3.25 54 0.271 5.14
Check section (ACI 11.5.3.1)
2.87 < 3.68 (OK)
2.9 < 3.68 (OK)
2.57 < 3.68 (OK)
1.11 < 3.68 (OK)
2.26 < 3.68 (OK)
(kN.m) 4.81 7.02 7.02 1.96 1.96
(kN.m) 19.13 27.91 27.91 7.81 7.81
(kN) 120.03 153.42 153.87 68.8 70.8
(kN) 172.63 433.42 191.1 31.2 66.13
(kN) 466 595.65 597.4 267.07 274.88
( 0.476 - 0.496 - 0.238
( 1.21 3.03 1.334 0.218 0.462
( 2.16 3.03 2.326 0.218 0.938
( 0.306
min
ACI 11.4.6.3 = 0.393
0.393
min
ACI 11.4.6.3 = 0.175
0.175
( mm ) 170.5 169.5 170 171 176
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( mm ) 137.5 - 162.5 - 160
4 leg @
4 leg @
4 leg @
2 leg @
2 leg @
d) Transverse reinforcement (at zone 2) :
Table 5 – 7(b) Transverse Reinforcement ( Zone 2 )
B1 B2 B3 B4 R1 Dimensions
( 350 400 450 400 450 400 - 200 400
c.c used (mm) 40 40 40 - 30
(kN) 61.13 91 34.12 - 21
(kN.m) 4 7 11.6 - 4.8
Check section (ACI 11.5.3.1)
1.67 < 3.68 (OK)
0.77 < 3.68 (OK)
0.83 < 3.68 (OK) - 1.71 < 3.68
(OK)
(kN.m) 4.81 7.02 7.02 - 1.96
(kN.m) 19.13 27.91 27.91 - 7.81
(kN) 120.03 153.42 153.87 - 70.8
(kN) 0 0 0 - 0
(kN) 466 595.65 597.4 - 274.88
( 0.344 - 0.21 - 0.233
( - - - - -
( 0.687 0 0.42 - 0.467
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( 0.306
min
ACI 11.4.6.3 = 0.393
0.393 - 0.175
4 leg @
4 leg @
4 leg @
2 leg @
2 leg @
Note : no need for another zone of transverse reinforcement for B4 due to its low lengths.
Beam Detailing :
The following graphs shows all beams sections detailing :
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5.3.3 Control of Deflection
a) Beam deflection control : For one End continuous ( the most severe case of available cases ) :
18.5900018.5
486.5
By Using ACI Table 9.5(b) for h = 400 mm Type of member: Roof or floor construction supporting or attached to nonstructural elements not likely to be damaged by large deflections (the part of total deflection occurring after attachment of nonstructural elements).
a) Maximum deflection due to sustained loads ( dead loads + partitions ) = 20 mm ( Analysis Output ) .
b) Maximum deflection due to live load = 6 mm ( Analysis Output ).
74 ( Equ. 5-57 )
74 ACI 9.5.2.5
Figure 5-13 Beams and Ribs section details
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4 20
450 4001256.6180000
0.00698
2 5
2
1 50 0.006981.483
20
20 1.483 29.66
29.66 6 35.66 240
9000240
37.5
b) Joist slab deflection control :
“I” beam calculation :
300 450 300
2 100 1050 1002 300
450 300 1050 100237.5mm
450 300
12300 450
3002
237.5 2.05 10
1050 100
121050 100
1002
300 237.5
1.42 10
3.47 10
“I” slab calculation :
200 300 9 300
2 100 9000 1002 300
200 300 9 9000 100275
9200 300
12300 200
3002
275
1.25 10
9000 100
12100 9000 350 275
5.8125 10
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1.83 10
3.47 101.83 10
0.1896 2
. 0.1896 0.2 ( ACI 9.5.3.2 shall apply )
Slabs without drop panel : minimum thickness = 125 mm ( 400 ) ∴OK
5.3.4 Design of Slabs : a) Slab Inside core :
Global moment in X direction :
Global moment
in Y direction :
Figure 5-14 Slab dimensions for deflection control calculation
Figure 5-15 Global moment in X for Inside core slab
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(-) 28.5kN.m
Assume: 14
2
150 20 142
123
∅
.
.2.093 ( Equ. 5-59 )
m = fy
0.85fc' =
.= 14.12 ( Equ. 5-60 )
1 1 ( Equ. 5-61 )
114.12
1 1 2 14.12 2.093
420 0.00517
As-req= ρ ×b ×d = 0.00517 1000 123 635.91mm
As-max 0.428 0.85 fc'
fy×β1 ×b×d ( β1 0.8 75 ( Equ. 5-62 )
= 0.428 × 0.85 fc'
fy 0.8 1000 123 = 2983.2 mm2
75 ACI 10.2.7.3
Figure 5-16 Global moment in Y for Inside core slab
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. . 76
0.25√35420
1000 123 1.4420
1000 123
433.1 governs 410
As-min= 433.1 mm2
Ashrinkage & temperatre= 0.0018 b h = 0.0018 × 1000 × 123 = 221.4
∶ As-req 635.91mm
Use 5 14 /1
a= Asfy
0.85 fc'b ( Equ. 5-63 )
a = 769.7×420
0.85 × 35 × 1000 = 10.866 mm
xdt
10.866
0.8 1230.11< 0.375
hence ∅=0.9 tension control checked
Table 5 – 8 Core Slab Design Result Direction X Direction Y DirectionDepth (mm) 150C.C (mm) 20
Moment (kN.m/m)
(-) (+)
(-)
(+)
28.5 11.2 27.9 8.44 443.1
221.4
2983.2
76 ACI 10.5.1 equ. (10.3)
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.
635.91 251 6383.2 2162
/1m
5∅14 mm
3∅14 mm (min)
5∅14 mm
3∅14 mm (min)
b) Slab above joist construction:
Slab above joist construction has a thickness of 100 mm, it shall be
considered to use shrinkage and temperature reinforcement to be distribution
in both sides.
A Strip of 1000 mm width b 1000mm
h 100mm
Ashrinkage&temperatre = 0.0018bh 77 ( Equ. 5-64 )
0.0018 1000 100 180mm
Use3∅10/1m
S10003
333mm
S 5hor450mmwhicheverisbigger 78
5 100 500mm, 450mmgoverns S 333mm
450 ,
77 ACI 7.12.2.1 (b) 78 ACI 7.12.2.2 (b)
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5.3.5 Typical Detailing :
Typical detailing drawings for all structural members meet the requirements
of (Details and Detailing of Concrete Reinforcement ACI 315-99 ) .
Beam Typical Detailing :
∎Longitudinal bars typical detailing :
In typical detailing, structural integrity requirements has been considered,
these requirements are as follows :
1) For joist construction ( R1 ) , more than one bottom bar is continuous ( 2
bars is used ) 79
2) For Perimeter beams ( B1) , not less than two bars of more than one-sixth
of tension reinforcement at support is continuous ( four bars represent of
4/9 of the total reinforcing at support) 80
79 ACI 7.13.2.1 80 ACI 7.13.2.2 (a)
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3) For Perimeter beams ( B1) , not less than two bars of more than one-
quarter of tension reinforcement at midspan is continuous ( two bars
represent of 1/3 of the total reinforcing at midspan ) 81
4) For Perimeter beams ( B1) , Reinforcement is anchored with standard
hook. 82
∎Hook typical detailing
Standard ACI hooks is used which meet the requirement of ACI 7.1.2 , with
12 hook length, and with of the following :
.
83 ( Equ. 5-65 )
0.24 1 420
1 √3517
12.5.3 (a), should be multiplied by 0.7 , hence 12
∎Bend diameters typical detailing
Bend of longitudinal bars measured from the inside of the bar meet the
requirement of ACI Table 7.2, all bends are used as 6 ( as all bar sizes are in
the range from No.10 through No.25 ) .
Bend of stirrups is used as 4 , which meets the requirement of ACI 7.2.2 .
∎Typical lab splices
Typical splices in tension :
Class B splice is used as required in ACI 12.15.1 , with 1.3 calculated as
follows :
81 ACI 7.13.2.2 (b) 82 ACI 7.13.2.1 83 ACI 12.5.2
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.
84 ( Equ. 5-66 )
1.3 1.3420 1 1
2.1 1 √3544
∎Typical splices in compression :
0.071 ( Equ. 5-67 )
0.071 420 30
Typical Detailing : The following graph shows the typical beams reinforcement :
84 ACI 12.2.2
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Figure 5-17 Beams and Ribs typical detailing
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Figure 5-18 Beams and Ribs typical detailing
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5.4 Design of Stairs
The staircase provided by the architecture drawings consists of a single landing with varies number of steps through the floors , it will be designed as a cantilever stairs supported on the surrounding shear-wall due to the short width of the stair which will provide economic sections and reinforcement but special requirements shall be considered during construction .
5.4.1 Stairs Specification :
Cantilever Stair
= 420 MPa , = 35 MPa. Live Load = 4.79 kPa.
Toppings :
Table 5 - 9 Stairs’ Toppings
Material Screed Mortar Natural Stone Steel Thickness (cm) 8 4 3 -
Unit-Weight (kN/m3) 22 18 24 78
117.5 85 120
85 ACI Table 9.5(a)
Figure 5-19 Stairs parameters
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5.4.2 Stairs Design :
a. Design of Land :
Load of Toppings 0.08 22 0.04 18 0.03 24 3.2
Load of Land 0.12 24 2.88
Total Dead Load 3.2 2.88 6.08 .
1.2 . . 1.6 . . 1.2 6.08 1.6 4.79 14.96 .
14.96 1.305 19.52 / /
219.52 1.175
213.48 .
120 20142
93
. . 93 1305 404.55 ( Equ. 5-68 )
∅ .
.
. .425.96 ( Equ. 5-69 )
4ɸ12
Check Spacing :
3 500
13054
326.25 360 500
Use 325
Check Shear Adequacy :
∅ ∅ 0.17 86 ( Equ. 5-70 )
∅ 0.75 0.17 √35 1175931000
82.43
V . . 3.66 ( Equ. 5-71 )
∅ V ∴
86 ACI 11.2.1.1
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b. Design of Step :
.
8 0.16 2 2.38
22.38
0.84
cos
1200.84
142.47
Wt. of step
( Equ. 5-72 )
0.142 0.142 0.16
20.25 24 1.33 /
Load of Topp. 0.25 0.16 3.2 1.31 /
Load of Steel handrail ( Equ. 5-73 )
0.01419 78
1.1750.94 /
Total Dead Load 1.33 1.31 0.94 3.59 /
Live Load 4.79 0.25 1.20 /
1.2 . . 1.6 . . ( Equ. 5-74 )
1.2 3.59 1.6 1.20 6.23 /
2
6.23 1.1752
4.3 .
( Equ. 5-75 )
0.142 0.142 0.162
0.222
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222 20142
195
∅ .
( Equ. 5-76 )
4.3 10
0.9 420 0.9 19564.82
. ( Equ. 5-77 )
1.4420
195 250 162.5
< Use = 2 ɸ 12 / Step
Check Shear Adequacy :
∅ ∅0.17 87 ( Equ. 5-78 )
∅ 0.75 0.17 √35 2501951000
36.77
V 2
6.23 1.1752
3.66
∅ V ∴
Transverse reinforcement :
use
1952
97.5
Use 10 @100
c. Reinforcement of the other direction :
0.0018 1.175 120 253.8 88 ( Equ. 5-79 )
Use 3 ɸ 12
87 ACI 11.2.1.1 88 ACI 7.12.2.1
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d. Reinforcement details for the each floor :
Rise = 16 cm , Gone = 25 cm , Width = 1.175 m
(*) Rounded steps instead of the lands through floor height
Use 2 ɸ 12 mm each step.
In case of ease of implementing during construction, 7 ɸ 12 mm / m can bu used for all landsUse 3 ɸ 12 mm for the other direction.
Table 5 - 10 Stair Reinforcement Details Land details Step Details
Bottom Elv. To Top Elv.
W (m)
Lmid
(m)
No. of
Steps
Mu
(kN.m) As-req. Barsɸ12
Mu (kN.m)
As (mm)
Barsɸ12
1.03 to 3.22 -(*) 4.950 15 -(*) -(*) -(*) 4.25 155.30
2
3.22 to 5 -(*) 4.950 11 -(*) -(*) -(*) 4.22 150.30 5 to 6.4 1.305 2.000 8 13.48 425.96 4 4.30 162.89 6.4 to 6.89 1.895 2.000 8 19.57 618.54 6 4.30 162.89 6.89 to 8.87 1.305 1.75 8 13.48 425.96 4 4.33 168.06 8.87 to 10 2.145 1.75 7 22.15 700.14 7 4.30 162.89 10 to 11.52 1.305 2.245 7 13.48 425.96 4 4.25 155.92 11.52 to 13 1.65 2.245 9 17.04 538.57 5 4.30 162.97 13 to 14.5 1.305 2.245 9 13.48 425.96 4 4.30 162.97 14.5 to 16 1.65 2.245 9 17.04 538.57 5 4.30 162.97 16 to 18.57 1.305 3.645 9 13.48 425.96 4 4.23 151.69 18.57 to 20.45 -(*) 3.895 15 -(*) -(*) -(*) 4.29 161.63 20.45 to 22.32 1.305 2.75 11 13.48 425.96 4 4.30 162.89 22.32 to 24.2 1.145 2.75 11 11.82 373.74 4 4.30 162.89 24.2 to 26.075 1.305 2.75 11 13.48 425.96 4 4.30 162.89 26.075 to 84.2 1.145 2.75 11 11.82 373.74 4 4.30 162.89 84.2 to 86.07 1.305 2.75 11 13.48 425.96 4 4.30 162.89 86.07 to 87.95 1.145 2.765 11 11.82 373.74 4 4.29 162.71
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The following figure shows the detailed stairs section:
Figure 5-20 Stairs section detailing
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Chapter 6 | Design of Lateral Loads Resisting System
6.1 Introduction
The following Lateral load systems will be considered:
1) Beams - Columns Frame System. 2) Shear Wall System with coupling beam.
A Shear Wall-Frame Dual System is adopted, considering also
additional lateral resisting member which is retaining wall to resist soil load and surcharge load.
6.2 Design of Columns
6.2.1 Design Strategy :
a. Preliminary design :
According to typical floor adopted (Waffle slab system); axial loads are resulted for each column in accordance to gravity loads only and preliminary design is performed using Design axial strength as follows :
, 0.80 0.85 89 ( Equ. 6-1 )
b. Slenderness effects :
Since Structural analysis software is used, P-delta Analysis is performed to consider slenderness effects (Second-order effects).
89 ACI 10.3.6.1
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c. Required Strength Determination (after analyzing the model) :
Using structural analysis results for the whole structure under the effects of gravity and lateral loads, internal forces are determined for each column.
Load Cases Considered according to ACI 9.2 :
1 1.4D
2 1.2D+1.6L
3 1.2D+1L+1W(X)
4 1.2D+1L+1W(Z)
5 1.2D+1L+1E(X)
6 1.2D+1L+1E(Z)
7 0.9D+1W(X)
8 0.9D+1W(Z)
9 0.9D+1E(X)
10 0.9D+1E(Z)
d. Design as axially loaded column :
Equation (5-1) is used to design columns for axial loads using 0.01 , for each column all load cases are checked.
e. Check as biaxial column and modify the design :
It’s required to check its adequacy using biaxial column analysis methods.
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Bresler reciprocal load method is used in accordance to ACI Commentary Sections 10.3.6 and 10.3.7 for calculation of capacity under biaxial bending. The following equation is used to determine column capacity (∅ ):
∅ ∅ ∅ ∅ 90 ( Equ. 6-2 )
The validity of Bresler equation is confirmed by checking that ∅ is equal to or greater than 0.1 ∅ . When ∅ is less than 0.1 ∅ , the axial force may be neglected and the section can be designed as a member subjected to pure biaxial bending according to the following equation :
1.0 ( Equ. 6-3 )
Where , are the design moments about x,y- axes and , are the moment strength about x,y- axes.
Note that biaxial analysis is done in imperial units.
f. Selection of lateral reinforcement :
Lateral reinforcement is selected in accordance to ACI 7.10.
6.2.2 Preliminary Dimensions :
Considering the following for the preliminary design :
a) Reinforced concrete tied columns are used. b) Gravity Loads Considered only.
90 ACI R10.3.6
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Equation (5-1) is used to determine axial strength for columns as follows for (1000 x 1000 mm) column with 28 ∅ 22 mm reinforcement:
, 0.85∅ 0.85 ( Equ. 6-4 )
, 0.85 0.65 0.85 35 1000 10643.4 420 10643.4
17630
The following graph shows the preliminary dimensions for columns :
Figure 6-1 Columns Preliminary dimensions
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6.2.3 Secondary Dimensions :
The following table shows structural analysis results for axial loads on columns for each floor and the corresponding modified sections according to equation (5-1), after these sections applied; another Analysis is performed to check values. Note that same design is done for every floor, but it would vary after the detailed design.
Table 6 - 1 Column Secondary Dimensions
Floor No. Maximum Axial (kN) Secondary Dimensions (mm) Capacity (kN)1 17058.2
1000 x 1000 17,630
2 15788.4 3 14513.5 4 13211.2 5 12471.8 6 11732.4 7 10969.3
800 x 800 11,444
8 10247.3 9 9527.7
10 8810.6 11 8095.2 12 7376.9 13 6658.1 14 5939.5
600 x 600 6,395
15 5253.9 16 4572.4 17 3871.0 18 3173.0 19 2477.1 20 1783.2 21 1090.4 22 574.0 23 98.10
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6.2.4 Column Design Sample :
The following two examples show the detailed procedures for designing columns, the same procedures are applied to all columns with all load cases using Excel spreadsheets ( Appendix 2 ).
Columns Considered:
Column (A) (Location: 1st floor) | Column (B) (Location: 21nd floor) as shown in the following figure :
Note : In this samples not all load cases are checked , as an example only two load cases are calculated.
Figure 6-2 Columns calculated samples
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a. Calculation of Column (A) Sample :
Internal Forces:
Table 6 – 2 (a) Internal forces Column(a) Sample
Design Case Load Case Fx (kN) Mx (kN.m) My (kN.m) 1.2D + 1.6L 14839.4 10.64 0.724
Dimensions: 1000 , 1000 Reinforcement: 24∅25mm 0.01178
a) Axial Design :
0.80 0.85 ( Equ. 6-5 )
0.800.65 0.85 35 1000 11780.97 420 11780.97
1000
17860.71 14839.4 Ok
b) Biaxial Check :
. ( Equ. 6-6 )
1000 2 40 2 10 25
10000.875
Two Interaction diagrams are used 0.75 and 0.9 , Interaction diagrams used are A-9b , A-9c in (Wight MacGregor Reinforced Concrete).
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x Direction :
ℓ ( Equ. 6-7 )
26.3715165.7 1
0.00174
From Interaction Diagrams (Appendix 2) → 2.56
2.56 1 39.3701 3968.01 kips
y Direction :
ℓ ( Equ. 6-8 )
335.7
15165.7 10.02213
From Interaction Diagrams → 2.56
2.56 1 39.3701 3968.01 kips
∅ 0.85 ( Equ. 6-9 )
Figure 6-3 Interaction Diagrams Properties
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0.65 0.85 35 1000 11780.97 420 11780.971000
22325.8 5001
Substitute in Bresler equation :
∅ ∅ ∅ ∅ ( Equ. 6-10 )
1∅
13968.01
13968.01
15001
∅ 3288.7
∅
3288.7 3324.02 (Not Ok)
Increase reinforcement to 28∅25
2.63 1 39.3701 4067.5 kips
∅ 5112.6 kips
1∅
14067.5
14067.5
15112.6
∅ 3377.2
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∅
3377.2 3324.02 (Ok)
Check the validity of Bresler equation:
∅ 0.1∅ ( Equ. 6-11 )
3377.2 511.26 (Ok) Bresler equation is valid.
c) Lateral reinforcement selection : According to ACI 7.10 :
10 Spacing of ties :
S = 16 = 400 mm S = 48 = 480 mm
S = Least Dimension = 1000 mm
S = 400 mm governs , Use S=200 mm for practical consideration Spacing between tied bars and untied bars = 120.8 mm < 150 mm (Ok) 91
d) Section Details : See columns sections (Column 2)
91 ACI 7.10.5.3
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b. Calculation of Column (B) Sample :
Internal Forces:
Table 6 – 2 (b) Internal forces Column(b) Sample
Design Case Load Case Fx (kN) Mx (kN.m) My (kN.m) 1.2D+1L+1E(X) 435.509 529.5 15.1
a) Preliminary Design : Secondary Dimensions:
600 , 600 Reinforcement:
12∅20mm 0.01047
b) Axial Design :
0.800.65 0.85 35 600 3770 420 3770
1000
6334.2 435.5 Ok
Note that no reduction to area has been done due to the high value of moment , hence in this case checking the moment before reducing the dimensions is essential.
c) Biaxial Check :
. ( Equ. 6-12 )
600 2 40 2 10 20
6000.8
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x Direction :
ℓ ( Equ. 6-13 )
15.1
435.5 0.60.0578
From Interaction Diagrams ( Appendix 2 ) → 2.51
2.51 0.6 39.3701 1400.6 kips
y Direction :
ℓ
ℓ ( Equ. 6-14 )
529.5
435.5 0.62.0264
From Interaction Diagrams → 0.123
0.123 0.6 39.3701 68.6 kips
∅ 0.85 ( Equ. 6-15 )
0.65 0.85 35 600 3769.9 420 3769.91000
7917.8 1773.58
Substitute in Bresler equation:
∅ ∅ ∅ ∅ ( Equ. 6-16 )
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1∅
11400.6
168.6
11773.58
∅ 67.93
∅
67.93 97.55 (Not Ok!)
Increase reinforcement from 12∅20mm to 16∅20mm and from previous procedures:
∅ 1468.67 kips
∅ 126.7 kips
∅ 1845
1∅
11468.67
1126.66
11845
∅ 124.4
∅
124.4 97.55 (Ok)
Check the validity of Bresler equation:
∅ 0.1∅ ( Equ. 6-17 )
124.4 184.5 (Not Ok!) Bresler equation is not valid, and since ∅ is less than 0.1 ∅ , the axial force would neglected and the section can be designed as a member subjected to pure biaxial bending according to the following equation :
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1.0 ( Equ. 6-18 )
Mx and My are the moment strength for the section in both direction. For 600 600 16∅20
→ 0.9 538.4 484.56 . .
1.0
529.5484.5
15.1484.5
1.0
1.124 1.0 (Not Ok !)
Increase reinforcement from 16∅20mm to 20∅20mm and from previous procedures:
For 600 600 20∅20
→ 0.9 680.5 612.45 .
1.0
529.5612.45
15.1612.45
1.0
0.889 1.0 (Ok)
d) Lateral reinforcement selection :
According to ACI 7.10 : 10
Spacing of ties : S = 16 = 320 mm
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S = 48 = 480 mm S = Least Dimension = 600 mm
S = 350 mm governs Spacing between tied bars and untied bars = 76 mm < 150 mm (Ok)
e) Section : See columns sections (Column 6)
6.2.5 Columns Final Design and Detailing:
Table 6 - 3 Columns Final Design
Type Dimensions Number
of bars Bar Diameter
No. of Columns b h
1 1000 1000 28 32 0.0225 12 2 1000 1000 28 25 0.0137 85 3 800 800 20 22 0.0118 60 4 800 800 28 28 0.0269 51 5 600 600 16 20 0.0139 131 6 600 600 24 20 0.0218 114
Figure 6-4 Column dimensions distribution for all elevations (a)
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Figure 6-4 Column dimensions distribution for all elevations (b)
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Columns Detailing:
The following graph shows the sections detailing for all columns types :
Figure 6-5 Columns cross section details
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Column-Column Connection Typical Detail :
The following graph shows the typical detailing for the connection between columns with different dimensions.
Figure 6-6 Columns Splice Details
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6.3 Design of Shear Wall
Shear walls shall resist lateral loads due to wind or earthquakes acting on the building. They should provide lateral bracing for the rest of the structure , and they will be designed to resist gravity loads transferred to the wall by the parts of the structure tributary to the wall, plus lateral-loads and moments about the strong axis of the wall.
Walls numbering:
Figure 6-7 Shear wall numbering
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6.3.1 General Specifications:
Preliminary Sections:
All shear walls of stories (1 to 12) have a thickness of 400 mm
All shear walls of stories (13 to 23) have a thickness of 300 mm
Load combinations :
1 1.4D2 1.2D+1.6L3 1.2D+1L+1W(X)4 1.2D+1L+1W(Z)5 1.2D+1L+1E(X)6 1.2D+1L+1E(Z)7 0.9D+1W(X)8 0.9D+1W(Z)9 0.9D+1E(X)10 0.9D+1E(Z)
Critical sections [ ACI (11.9.5) ] :
Table 6 - 4 Shear-Wall Critical Sections
Shear Wall
(mm)
/ (mm)
/ (mm)
Story height (mm)
Critical Section
1 , 2 12500 6250 45500 4125
4125 3 , 5 2800 1400 1400 4 , 6 6600 3300 3300
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6.3.2 Shear Wall Internal Forces:
Internal forces of all shear walls were carried out at each floor with their critical load combination for each shear, axial and Moment.
a) Internal forces for SW1,SW2 :
Table 6 – 5 (a) Shear-Wall Internal forces
Floor
S W 1 S W 2 Vu
(kN) [L.C]
Pu (kN) [L.C]
Mu(kN.m)
[L.C]
Vu(kN) [L.C]
Pu (kN) [L.C]
Mu (kN.m)
[L.C] 1 6503 [6] 24278 [2] 85058 [6] 3976 [6] 36875 [5] 90549 [6]2 5726 [6] 23950 [2] 76276 [6] 4036 [10] 35306 [5] 66990 [6]3 5420 [6] 23179 [2] 63260 [6] 4226 [10] 34975 [5] 49966 [6]4 5173 [6] 22437 [2] 53755 [6] 4129 [6] 32861 [5] 42536 [6]5 5016 [6] 21640 [2] 47814 [6] 3987 [10] 30735 [5] 37931 [6]6 4921 [6] 20782 [2] 42641 [6] 3836 [10] 28519 [5] 33910 [6]7 4865 [6] 19920 [2] 37568 [6] 3725 [10] 26281 [5] 30167 [6]8 4738 [6] 19005 [2] 32500 [6] 3603 [10] 24026 [5] 26607 [6]9 4575 [6] 18010 [2] 27837 [6] 3468 [10] 21801 [5] 23365 [6]
10 4390 [6] 16958 [2] 23401 [6] 3326 [10] 19622 [5] 20303 [6]11 4185 [6] 15833 [2] 19282 [6] 3207 [10] 17483 [5] 17406 [6]12 3944 [6] 14616 [2] 15562 [6] 3060 [10] 15402 [5] 14639 [6]13 3647 [6] 13205 [2] 11727 [6] 2808 [10] 13385 [5] 11759 [6]14 3389 [6] 12042 [2] 8761 [6] 2605 [10] 11527 [5] 9325 [6]15 3073 [6] 10946 [2] 5808 [6] 2361 [10] 9708 [5] 6979 [6]16 2723 [6] 9825 [2] 3269 [6] 2083 [10] 7984 [5] 4882 [6]17 2361 [10] 8659 [2] 1251 [6] 1777 [10] 6931 [2] 3117 [6]18 1979 [10] 7455 [2] 1421 [10] 1452 [10] 5917 [2] 1586 [10]19 1560 [6] 6255 [2] 1936 [10] 1213 [6] 4925 [2] 505 [5]20 1092 [10] 5041 [2] 2327 [10] 940 [10] 3911 [2] 746 [10]21 685 [6] 3873 [2] 2218 [10] 692 [10] 2947 [2] 1174 [10]22 233 [10] 2823 [5] 1631 [10] 454 [6] 1974 [2] 1254 [10]23 122 [6] 1699 [5] 1115 [10] 203 [6] 1068 [2] 1056 [10]
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b) Internal forces for SW3,SW5 :
Table 6 – 5(b) Shear-Wall Internal forces
Floor
S W 3 S W 5 Vu
(kN) [L.C]
Pu (kN) [L.C]
Mu (kN.m)
[L.C]
Vu (kN) [L.C]
Pu (kN) [L.C]
Mu (kN.m)
[L.C] 1 643 [9] 7092 [2] 3604 [5] 821 [6] 17875 [6] 3478 [5] 2 1503 [5] 6126 [2] 1665 [5] 1417 [5] 15210 [6] 1642 [5] 3 1587 [5] 5476 [2] 954 [9] 1498 [5] 12350 [6] 955 [9] 4 1421 [5] 5339 [2] 1019 [9] 1317 [5] 11314 [6] 1017 [9] 5 1147 [5] 5155 [2] 936 [9] 1078 [5] 10453 [6] 918 [9] 6 963 [5] 4942 [2] 790 [9] 910 [5] 9605 [6] 763 [9] 7 816 [9] 4674 [2] 658 [9] 772 [9] 8830 [6] 634 [9] 8 915 [9] 4452 [2] 530 [9] 859 [9] 8019 [6] 513 [9] 9 709 [9] 4221 [2] 451 [9] 650 [9] 7223 [6] 438 [9]
10 687 [9] 3966 [2] 368 [9] 630 [9] 6465 [6] 363 [9] 11 650 [9] 3694 [2] 295 [9] 605 [9] 5714 [6] 292 [9] 12 594 [9] 3429 [2] 301 [9] 572 [5] 5019 [6] 278 [9] 13 648 [5] 3149 [2] 129 [6] 664 [5] 4338 [6] 119 [9] 14 623 [9] 2896 [2] 237 [6] 557 [9] 3626 [6] 173 [5] 15 531 [9] 2572 [2] 272 [5] 502 [9] 3052 [6] 254 [9] 16 520 [9] 2298 [2] 306 [5] 516 [9] 2487 [6] 284 [9] 17 643 [9] 7092 [2] 3604 [5] 821 [6] 17875 [6] 3478 [5] 18 1503 [5] 6126 [2] 1665 [5] 1417 [5] 15210 [6] 1642 [5] 19 1587 [5] 5476 [2] 954 [9] 1498 [5] 12350 [6] 955 [9] 20 1421 [5] 5339 [2] 1019 [9] 1317 [5] 11314 [6] 1017 [9] 21 1147 [5] 5155 [2] 936 [9] 1078 [5] 10453 [6] 918 [9] 22 963 [5] 4942 [2] 790 [9] 910 [5] 9605 [6] 763 [9] 23 816 [9] 4674 [2] 658 [9] 772 [9] 8830 [6] 634 [9]
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c) Internal forces for SW4,SW6 :
Table 6 – 5 (c) Shear-Wall Internal forces
Floor
S W 4 S W 6 Vu
(kN) [L.C]
Pu (kN) [L.C]
Mu (kN.m)
[L.C]
Vu (kN) [L.C]
Pu (kN) [L.C]
Mu (kN.m)
[L.C] 1 3021 [5] 16583 [5] 35516 [5] 3023 [5] 27098 [6] 34990 [5]2 3433 [5] 13739 [5] 20834 [5] 3196 [5] 23341 [6] 22097 [5]3 3059 [9] 11102 [5] 10653 [9] 3010 [9] 22077 [6] 10982 [9]4 2798 [9] 10525 [5] 8896 [9] 2708 [9] 20189 [6] 8919 [9]5 2518 [9] 10161 [5] 7922 [9] 2451 [9] 18910 [6] 7652 [9]6 2381 [9] 9942 [5] 6975 [9] 2302 [9] 17683 [6] 6245 [9]7 2349 [5] 9812 [5] 5865 [9] 2172 [9] 16530 [6] 5096 [9]8 2255 [5] 9683 [5] 4566 [9] 2108 [9] 15353 [6] 4068 [9]9 2088 [5] 9336 [5] 3846 [9] 1907 [9] 14171 [6] 3175 [9]
10 2062 [5] 8987 [5] 3008 [9] 1853 [9] 12970 [6] 2410 [9]11 2030 [5] 8572 [5] 2289 [9] 1840 [5] 11758 [6] 1733 [9]12 2003 [5] 8124 [5] 1751 [9] 1809 [5] 10563 [6] -1165 [9]13 1863 [5] 7593 [5] 1028 [6] 1646 [5] 9329 [6] 1111 [3]14 1719 [5] 7115 [5] 1679 [5] 1557 [9] 8306 [6] 1933 [5]15 1605 [5] 6589 [5] 2004 [5] 1445 [9] 7192 [6] 2308 [5]16 1448 [5] 6046 [5] 2454 [5] 1284 [9] 6163 [6] 2715 [5]17 1252 [9] 5495 [5] 3005 [5] 1081 [9] 5582 [5] 3138 [5]18 1100 [9] 4835 [5] 2964 [5] 916 [9] 4775 [5] 3025 [5]19 822 [9] 4192 [5] 3153 [5] 739 [9] 4221 [5] 3186 [5]20 627 [9] 3450 [5] 2744 [5] 552 [9] 3383 [5] 2741 [5]21 379 [9] 2657 [5] 2612 [5] 320 [9] 2745 [5] 2544 [9]22 217 [5] 1792 [5] 1729 [9] -229 [5] 1815 [5] 1831 [9]23 304 [5] 988 [5] 1070 [9] -264 [5] 1037 [5] 1224 [9]
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6.3.3 Calculation for (SW1) Sample :
400 , 12500
6503 ( combination 6 )
24278 ( combination 2 )
85058 . ( combination 6 )
0.75
Concrete Cover = 50 mm ( minimum required in ACI 14.3.4 )
a. Horizontal reinforcement :
Maximum Spacing : 2500 92
3 3 400 1200
450 ( governs )
0.0025 93
0.0025 1000
0.0025 400 1000 1000 /m
Use 10 12 (5 bars at each side)
10005
200
92ACI (11.9.9.3) 93 ACI (11.9.9)
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b. Vertical reinforcement :
0.17 94 ( Equ. 6-19 )
0.8 95 ( Equ. 6-20 )
0.8 12500 10000
0.75 0.17
0.75 0.17 1 √35 400 10000 /1000 3017.2
6503 3017.20.75
4647.73
96 ( Equ. 6-21 )
2 12 /4 420 10000200
/1000 4750
4647.73
0.0025 0.5 2.5 0.0025 97 ( Equ. 6-22 )
10 12 /41000 400
0.00283
0.0025 0.5 2.59112.5
0.00283 0.0025 0.00172 0.0025
0.0025
0.0025 0.0025 12500 40012500 /12.5
1000 /
Use 10 12 mm / meter
94 ACI (11.9.5) 95 ACI (11.9.4) 96 ACI (11.9.9) 97 ACI (11.9.9.4)
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10005
200
Maximum Spacing :
4166.7 200 98
3 3 400 1200 200
450 200
200
Moment capacity :
0.00283 0.0339 ( Equ. 6-23 )
0.139 ( Equ. 6-24 )
.
. .
. . .12500 2853.4 ( Equ. 6-25 )
2853.410000
0.285 0.375
∶ 0.9
( Equ. 6-26 )
10124
12.5 42012500 2853.4
12500/1000 4582.18
( Equ. 6-27 )
4582.18 1000125002
24278 100012500 2853.4
2145738.7 .
131164.83 . 85058 . OK
98 ACI (11.9.9.5)
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Compression Check :
Ag = 5000000
10∅12 / → 125∅12/
0.80 0.85 99 ( Equ. 6-28 )
0.80 0.65 0.85 35 5000000 14137.2 420 14137.280219
80219 24278
6.3.4 Shear Wall Final Design
Shear Walls Design for floors (1 to 12) :
99 ACI (10.3.6.1) Equ. 10-2
Table 6 – 6(a) Shear-Wall Final Design
No. /1 /
/1 /
Check Shear(kN)
Check Moment (kN.m)
Check Axial(kN)
∅ ∅ ∅ ∅ ∅S W 1 5∅12 5∅ 12 3017 3563 6580 5726 124774 85058 80219 24278S W 2 5∅12 5∅ 12 3017 3563 6580 4226 107039 90549 80219 36875S W 3 5∅14 5∅ 12 676 1086 1762 1587 6924 3604 17969 7092S W 4 5∅12 5∅ 12 1593 1881 3474 3433 36468 35516 42356 16583S W 5 5∅14 5∅ 12 676 1086 1762 1498 6784 3478 17969 17875S W 6 5∅12 5∅ 12 1593 1881 3474 3196 37998 34990 42356 27098
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Shear walls Design for floors (13 to 23) :
6.3.5 Walls Subjected to Axial Tension :
Table 6 – 7 Shear-Walls In Tension
NO. Vu (kN) [L.C]S W 1 No tensionS W 2 No tensionS W 3 No tensionS W 4 15.594 [15]S W 5 No tensionS W 6 No tension
Check for SW4:
0.17 1 . 100 ( Equ. 6-29 )
0.75 0.17 10.29 15.594 1000
68001 √35 400 0.8
6800 549.79 14.594
100 ACI (11.2.2.3) Equ. 11-8
Table 6 – 6 (b) Shear-Wall Final Design
No. /1 /
/1 /
Check Shear ( kN )
Check Moment (kN.m)
Check Axial(kN)
∅ ∅ ∅ ∅ ∅S W 1 4∅12 4 ∅12 2263 1384 3647 3647 79187 11727 60308 13205S W 2 4∅12 4 ∅12 2263 545 2808 2808 71800 11759 60308 13385S W 3 4∅12 4 ∅12 507 141 648 648 3070.4 341 13509 3149S W 4 4∅12 4 ∅12 1195 668 1863 1863 15008 4192 31842 7593S W 5 4∅12 4 ∅12 507 157 664 664 1844 308 13509 4338S W 6 4∅12 4 ∅12 1195 451 1646 1646 15085 3186 31842 9329
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6.2.6 Design of Stairs Walls and Elevator Walls
Stairs walls and elevator walls ( W1,W2,W3,W4,W5,W6, W7,W8 ) are designed as a uni-axial compression members which forces subjected from the stairs and the elevators.
a) Horizontal reinforcement :
Maximum Spacing :
760 101
3 3 200 600
450 ( governs )
0.0025 102
/ 0.0025 1000 0.0025 200 1000 500 /m
Use 6 12 (4 bars at each side)
10003
333.3
Use 300
0.0025 0.5 2.5 0.0025 103 ( Equ. 6-30 )
6 12 /41000 200
0.00339
0.0025 0.5 2.5913.8
0.00339 0.0025 0.0095 0.0025
0.0025
0.0025 0.0025 3800 2001900 /3.8
500 /
101 ACI (11.9.9.3) 102 ACI (11.9.9) 103 ACI (11.9.9)
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Use 8 12 / meter
10004
250
Use 250
Maximum Spacing :
1266.6 250 104
3 3 400 1200 250
450 250
250
Compression Check :
760000
8∅12 / → 30.4∅12/
From ACI 10.3.6.1 Equ.10-2
0.80 0.85 105 ( Equ. 6-31 )
0.80 0.65 0.85 35 760000 4297.7 420 4297.7 /100012629
12629 12600
104 ACI (11.9.9.5) 105 ACI (10.3.6.1) Equ. 10-2
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The following graph shows typical detailing for the Shear Wall:
Figure 6-8 Shear wall typical detailing
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6.4 Design of Coupling Beams
The two shear walls which was revealed in section 6.2 would be coupled by beams spanning across a doorway The coupling beams will be designed to have enough stiffness to resist the force of the two independent shear walls acts as one solid cantilever part by transmitting the shear forces from one wall to the other .
6.4.1 Preliminary Sections : All coupling beams of stories (1 to 12) have a thickness of 400 mm (Coupling Beam 1)
All coupling beams of stories (13 to 23) have a thickness of 300 mm (Coupling Beam 2)
6.4.2 Coupling Beam Design :
a) Coupling beam 1 (400 1000) 212
b = 400 mm , h = 1000 mm , ℓ = 2200 mm
ℓ 22001000
2.2
(hence Use intersecting groups of diagonal bars as ACI 21.9.7.3 )
∅ 0.85 ( Seismic Design Category D ) 106
2 0.83 107 ( Equ. 6-32 )
Assume 12∅12 1357.19 , use 18°
2 1357.19 420 18 0.83√35 400 1000
352.3 1964.14
352.3
106 ACI 9.3.4 (C) 107ACI 21.9.7.4 Equ. 21-9
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∅.
249.41 ( OK )
2
4002
200mm
5
4005
80mm
Use a section of 200 200 diagonal bars out-to-out dimension.
∎Spacing of transverse reinforcement [ ACI 21.6.4.3 ] :
a) ¼ 400 = 100mm b) 6 12 = 72 mm
c) 100 100 194.6 , take
150
Use spacing ( s ) = 70 mm
0.3 1 108 ( Equ. 6-33)
0.370 200 35
420 240 240200 200
1 272.22
0.09 109 ( Equ. 6-34)
0.0970 200 35
420 105
Use 4 leg ∅10 at each direction = 314.16 272.22 ( OK )
∎Development length of diagonal bars :
Diagonal bars should be developed into the wall not less than 1.25 ℓ
ℓ .
110 ( Equ. 6-35)
Ψ 1.3, Ψ 1 as specfied in ACI 12.2.4 (a) ] (more than 300 mm of concrete casted below and uncoated reinforcement is used)
108 ACI 21.6.4.4 (b) Equ. 21-4 109 ACI 21.6.4.4 (b) Equ. 21-5 110 ACI 12.2.2
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ℓ 420 1.3 1
2.1 1 √35 12 527.38
Developed length = 1.25 527.38 659.23
Extend diagonal bars a distance of 700 mm into the wall.
∎Additional longitudinal bars in beam parameter:
Use 10∅12 as shown.
Serviceability requirement :
Vertical face :
0.002 0.002 400 300 240 4∅12
Horizontal face :
0.002 0.002 400 150 120 3∅12
Use transverse reinforcement ∅10 @ 200 mm
Figure 6-9 Coupling beam rebar
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6.4.3 Structural Drawings for Coupling Beams:
Figure 6-10 Coupling beam cross section details
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6.5 Design of Retaining Walls
Retaining walls are used to provide stability for soil , it will be used in the basement and it be would be designed to withstand the exerted loads against failure .
The following plan shows the retaining walls for ground elevation of the Tower :
Figure 6-11 Retaining walls plan
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The following figure shows a view for the retaining wall.
6.5.1 Loads on Retaining Walls :
The following figure shows the loads acting over the retaining wall :
Figure 6-12 Retaining wall
Figure 6-13 Loads acting over the retaining wall
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a) Soil loads:
Soil coefficients : Referring to the attached Geotechnical report :
(∅ 20 , 12.6 / , 18.59 /
∅
∅ 0.49 ( Equ. 6-40)
2 √ 0.49 18.59 3.3 2 12.6 √0.4912.43 / ( Equ. 6-41)
b) Surcharge loads :
( ASCE 07-2010 ) Table 4.1 :
For Sidewalks , vehicle drive ways . 11.97 /
For 300 mm layer of Asphalt road , ( 0.3 21 / 6.3 /
1.2 6.3 1.6 11.97 26.712 /
0.49 26.712 /
Figure (6-14) shows loads over the retaining wall .
Figure 6-14 Loads acting over the retaining wall
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Load cases :
a) 1.2 D + 1.6 L + 1.6 H ( if soil load combined with other loads are critical ) ( ACI 9.2.5.a)
b) 1.6 H ( if soil counter acts other loads ) ( ACI 9.2.5.b)
6.5.2 Design of Retaining Walls :
a) As a compression member :
Retaining walls designed for axial load as well as flexure ( ACI 14.4 )
Assume width = 200 mm , length of strip = 9000 mm
Staad Pro output for axial stress : Sy = 0.45575 ( N /
0.45575 × 9000 ×200 820.35
∅ 0.8 ∅ 0.85 111 ( Equ. 6-42)
820.35=0.8 0.65 0.85 fc' 9000× 200-As + 420 × As
137216
No need for compression steel reinforcement, except if it’s required by flexure.
b) As a flexure member :
∶ 72.2 .
. 1. :
72.2 . , CC = 40 mm , ds = 12 mm , b = 1000 mm , h = 200 mm
1449 Use 8 ∅ 16
∶
17.2 .
111 ACI 10.3.6.2
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17.2 . , CC = 40 mm , ds = 12 mm ,
b = 1000 mm , h = 200 mm
460 Use 3 ∅ 16
∶ 27.3 .
17.2 . , CC = 40 mm , ds = 12 mm ,
b = 1000 mm , h = 200 mm
538.2 Use 4 ∅ 16
c) Shear design:
ACI(11.9) : Design for shear forces perpendicular to face of wall shall be in accordance with provisions for slabs in 11.11 .
Wall is considered as a one-way slab construction supported by the foundation and the horizontal slab.
For 1 m length strip :
200 40 12162
140
∅ ∅0.17 ( Equ. 6-44)
∅ 0.75 0.17√35 1000 140 105.6
Figure 6-15 Bending moment diagrams
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Staad pro output for shear stress :
Case : 1.2D + 1.6 L + 1.6 H
SQy (top ) = 0.2479 N/mm2 , Vu (top) = 0.2479 1000 20049.58
SQy (bottom ) = 0.28245 N/mm2 , Vu (bottom) = 0.282451000 200 56.49
Case : 1.6 H
SQy (top ) = 0.0838 N/mm2 , Vu (top) = 0.0838 1000 20016.78
SQy (bottom ) = 0.2478 N/mm2 , Vu (bottom) = 0.2478 1000200 49.56
Max Vu>∅ Vc
No shear reinforcement required.
d) Vertical and horizontal reinforcement :
Minimum ratio of vertical reinforcement “ “ = 0.0012 112
4 14 14
41000 200
0.003 0.0012
Minimum Horizontal reinforcement “ “ = 0.002 113
0.002 1000 200 400mm2 →
Use4∅12 / m
112 ( ACI 14.3.2 ) 113 ( ACI 14.3.3 )
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6.5.3 Structural Detailing for Retaining Wall : The following graph shows the typical detailing for the retaining wall :
Figure 6-16 Retaining wall cross section detailing
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Chapter 7 | Design of Substructure
7.1 Introduction
A Geotechnical Investigation Report has been prepared on April 2010 for the soil and the following recommendation has been reported :
“Based on the in-situ and lab tests it is evident that upper layers up to 6 meters of soil is loose, and since high concentrated loads expected from the superstructure, therefore, deep foundation using bored and cast in place reinforced concrete Piles is recommended”
The deeper layers are of cohesive nature, hence, the bearing capacity calculations will relay on the cohesion parameter calculated from the unconfined compressive strength method .
7.2 Strategy
A piled/cap system generally consists of two structural elements, piles and concrete cap ; the function of the cap is to distribute the loads from the superstructure to the piles , which will transfer the load to the soil. Figure (7-1) shows how the column is connected to the piles.
Figure 7-1 Foundation system
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7.3 Pile Distribution
A preliminary distribution of piles under cap has been illustrated as follows:
7.4 Cap Thickness Computation
Minimum mat thickness based on punching shear at critical columns based on column load and shear perimeter.
It is common practice not to use shear reinforcement so that the mat depth is a maximum.
The pile cap is divided into two parts with different thicknesses (A1,A2) as shown:
Figure 7-2 Piles distribution
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Punching Shear Check (Two way shear) :
For area 1:
From model, Pu 17618kN (Interior column 1m 1m )
Try h = 1500 mm → 1500 75 28/2 1411
17618
17618 13.56 1.416 1 1.416 1 17539.2
Computation of :
Vc shall be the smallest of :
0.17 1 ′ 114 ( Equ. 7-1)
0.083 2 ′ 115 ( Equ. 7-2)
114 (5.8) ACI 11.11.2.1 (equ. 11-31) 115 (5.9) ACI 11.11.2.1 (equ. 11-32)
Figure 7-3 Cap thickness variation
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0.33 ′ 116 ( Equ. 7-3) ∅ 19925 17618 kN (Ok)
Hence ( h1 = 1500 mm )
For area 2:
Model Result : , Pu 2041kN (Edge column 0.6m 0.6m)
Try h = 500 mm → 500 75 28/2 411
2027.0
∅ 2300 2041 kN (Ok)
Hence( h2=500 mm )
7.5 Modeling
The foundation system has been modeled using STAAD Pro , the figure (7-4) shows the rendered model .
The piles was modeled to have a preliminary dimensions of 1m diameter and 25m and to be supported by Vertical springs with kv= 2000000 kN/m (From geotechnical report) , Modeled in STAAD Pro as Fixed But support with (KFY=2000000 kN/m).
116 (5.10) ACI 11.11.2.1 (equ. 11-33)
Figure 7-4 Foundation Model
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7.5.1 Loads :
Imposed loads on the piles :
1. Columns loads : Forces applied to the foundation listed as shown:
Note that the piles are designed with (1L+1D) combination and a factor of safety from conventional design method, and for cap design (1.2D+1.6L) combination is considered.
Table 7-1 Columns Loads upon Pile cap
Column No.For pile Design For Cap Design
1L+1D 1.2D+1.6L 1 279 344.8 2 486 606 3 466 580.8 4 462 575.2 5 459 570.8 6 465 579.2 7 483 602 8 259 318 9 1190 1484
10 6147 7678.4 11 10391 13027.2 12 12009 15044.8 13 8824 10988.8 14 2202 2761.2 15 979 1242.8 16 483 602 17 1637 2052.4 18 11716 14720.8 19 12560 15836.4 20 8370 10502 21 10972 13750.8 22 8175 10206.4 23 930 1180.8 24 783 1089.2 25 1601 2006.8 26 13575 17056
27 9225 11595.628 8496 10670.829 10974 13755.230 938 1190.8 31 465 579.2 32 1632 2046 33 10073 12613.634 11660 14640.435 8271 10384.436 11045 13880 37 8607 10777.238 930 1180.8 39 464 578.8 40 1182.8 1475.6841 2718 3416.8 42 9201 11490 43 11925 14934 44 8706 10874.845 3987 4974.8 46 982 1246.8 47 483.4 602.64 48 307 383.2 49 537 673.6 50 516 647.2 51 510 638.8 52 502 628.4 53 515 646 54 535 671.2 55 277.8 343.28
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2. Self-weight of Cap :
The self-weight for the cap and piles is considered.
From analysis : The maximum axial force exerted on piles :
4230
7.6 Pile Design
7.6.1 Soil Parameters :
The following graph shows soil profile:
Figure 7-5 Soil Profile with soil parameters
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7.6.2 Design Theory : Piles were designed to resist service loads, conventional method was adopted, both pile shaft resistance and end bearing resistance are considered to withstand applying loads ( Qu Qf Qb ) .
.
7.6.3 Design Procedure : Pile Dimensions : Take L = 27 m , D = 1 m
( Equ. 7-4)
Where : Qb = Base resistance (kN) , Qf = Shaft resistance (kN)
Base Resistance calculation :
For cohesive soil : ( Equ. 7-5)
9 425 9 0.785 3004.15
Figure 7-6 Pile resisting mechanism
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Shaft resistance :
The pile is bored through 4 layers ; three of them are non-cohesive soils and one is cohesive soil.
For non-cohesive soil : ′ ( Equ. 7-6)
∶
Table 7-2 Frictional pile resisting
L 5 32 0.09 20.5 14.53 37 0.35 57.7 95.27 30 0 99.7 0
For cohesive soil :
= α C ( Equ. 7-7 ) α 0.45
C 425 0.45 425 37.7 7210
Figure 7-7 Pile resisting mechanism
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Total resistance :
. . ( Equ. 7-8 )
3004.153.5
14.5 95.2 72101.5
5738.13
Efficiency for group piles :
∑ ( Equ. 7-9 )
η 1
θ ( Equ. 7-10 )
Where (Deg) = tan
θ tan13
18.43
η 12 2 1 2 2 1
90 2 2θ 100% 79.5%
5738.13 0.795 4562.8 > 4230 kN (Ok) Hence D=1m, L=27 m
Structural Design for piles :
For reinforcement , use :
0.0110004
7853.98
Use 16 ∅25
Check Pile capacity:
4230
Figure 7-8 Group Pile efficiency determination
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∅ 0.85 0.85 ( Equ. 7-11 )
∅ 0.750.85 0.85 35 785398.2 7853.98 420 7853.98
1000
16849
∅
Use 16 ∅25
Spacing = 157.3 1.5 40
Design of spiral:
Spiral 12
124
113.1
1000 2 75 850
8504
567450.2mm
0.425 1 ( Equ. 7-12 )
0.425785398.2567450.2
135420
0.0136
( Equ. 7-13 )
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0.0136850 113.1
567450.2→ 39.1
25
75
Use S=40 mm
7.6.4 Differential Settlement Check :
∆ 2.115
∆ 0.462
61.08
Differential settlement ( ∆ ) = ∆ ∆ 1.653 25 APPENDIX 3.A
Differential building slope= ∆ ∆ 0.000027 0.001 (Ok)
APPENDIX 3.B
Hence, ,this movement will not cause any structural or architectural distress.
Figure 7-9 Differential settlement
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7.6.5 Pile Cap Design : 1. Analysis Results
X-X Direction Moment Results :
Y-Y Direction Moment Results :
Figure 7-11 Y-Y Direction Moment Results
Figure 7-10 X-X Direction Moment Results
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2. Design sample for Area1 X– X Direction (-) :
(-) 2274kN.m
Assume: 32
2
1500 75 322
1409
∅
.1.27 ( Equ. 7-14 )
m = fy
0.85fc' =
.= 14.12 ( Equ. 7-15 )
1 1 ( Equ. 7-16 )
114.12
1 1 2 14.12 1.27
420 0.0031
As-req= ρ ×b ×d = 0.031 1000 1409 4368mm
As-max 0.428 0.85 fc'
fy×β1 ×b×d ( β1 0.8 ) 117 ( Equ. 7-17 )
= 0.428 × 0.85 ×35
420 0.8 1000 1409 = 34172.9 mm2
.
. 118 ( Equ. 7-18 )
0.25√35420
1000 1409 1.4420
1000 1409
4961.8 governs 4696.6
As-min= 4961.8 mm2
Ashrinkage & temperatre= 0.0018 b h 119 ( Equ. 7-19 )
117 ACI 10.2.7.3 118 ACI 10.5.1 equ. (10.3)
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= 0.0018 × 1000 × 1500 = 2700
∶ As-req 4961.8mm
Use 7 32
a= Asfy
0.85 fc'b ( Equ. 7-20)
a = 5629.7×420
0.85 × 35 × 1000 = 79.47 mm
xdt
79.47
0.8 14090.0705< 0.375
(hence ∅=0.9 tension control checked
3. Foundation Design results :
Table 7-3 Foundation Design Results
Area Area 1 Area 2 Direction X Direction Y Direction X Direction Y Direction
Depth (mm) 1500 500
C.C (mm) 75
Moment (kN.m/m)
(-)
(+)
(-)
(+)
(-)
(+)
(-)
(+)
2274 1092 3291 1139 380.6 250 188 125 4961.8 1461.4
2700 900
34172.9 10065.1
.
4365.1 2071.8 6383.2 2162 2535.6 1639.4 1231.7 813
7∅32 mm
7∅32 mm
8∅32 mm
7∅32 mm
5∅20 mm
5∅20 mm
5∅20 mm
5∅20 mm
119 ACI 7.12.2.1 (b)
a
Apendixes
Appendix 1 | Architectural Drawings
1A Hotel Tower Plans and Sections.
Note:
Levels (+16.00 ,+20.45 , +24.20) are identical. Levels (27.95 , 31.70 , 35.45 , 39.20 , 42.95) are identical. Levels (46.70 , 50.45 , 54.20 , 57.95 , 61.70) are identical.
A single plan for each is printed.
1B Façade
1C Stairs
1D Toppings
b
LEVEL HF0 (+5)
c
LEVEL HF1 (+10)
d
e
f
g
h
i
j
k
l
m
n
Side View
o
Façade Details
p
Stairs Details
q
Toppings
r
Appendix 2 | Interaction Diagrams
s
t
Appendix 3 | Tolerable Differential Settlement
u
Appendix 4 | Excel Sheets Calculations
Most design calculations in this project are carried out using spreadsheets prepared by us using Microsoft excel , the following are the main excel spreadsheets :
4A) Rectangular Section - Flexure Design .
4B) Rectangular Section - Torsion and Shear Design.
4C) Biaxial Column Design
4D) Column Moment Capacity
4E) Shear wall Design
4F) Stairs Design
v
4A) Rectangular Section - Flexure Design .
w
4B) Rectangular Section - Torsion and Shear Design
x
4C) Biaxial Column Design
y
4C) Biaxial Column Design (Continued)
z
4D) Column Moment Capacity
aa
4E) Shear wall Design
bb
4E) Shear wall Design (Continued)
cc
4F) Stairs Design
dd
4F) Stairs Design (Continuous)
ee
Appendix 5 | Ss , S1 Seismic Parameters
Values of and has been used based on USGS email
References
1. ACI Committee 318 of American Concrete Institute, “ Building Code Requirements for Structural Concrete ( ACI 318-11 ) “.
2. ACI Committee 315 of American Concrete Institute, “ ACI Detailing Manual-2004 , Details of Concrete Reinforcement“.
3. American Society of Civil Engineers, “ Minimum Design Loads for Buildings and Other Structures (ASCE 7-10) “.
4. Braja M. Das , “ Principles of Foundation Engineering 6th Edition “.
5. David Anthony Fanella, Portland Cement Association PCA “ Time-saving Design Aids for Reinforced Concrete “ .
6. Edward G. Nawy, “ Reinforced Concrete (A Fundamental Approach) 5th Edition”.
7. Joseph E. Bowles “ Foundation Analysis and Design 6th Edition”.
8. James K. Wight & James G. MacGregor “ Reinforced Concrete Mechanics and Design”.
9. M. Nadim Hassoun & Akthem Al-Manaseer“ Structural Concrete Theory and Design 4th Edition “.
10. Mohammed B. Abohedma, and Milad M. Alshebani “Wind Load
Characteristics in Libya”
11. Website “ United States Geological Survey www.USGS.org “
12. Website “ Polypropylene Waffle Mould Sizes www.kasetkalip.com “
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