Engineer's Handbook - ACI/AISC

311 Pages·2017·5.96 MB·English

Tekla Structural Designer
2017
Engineer’s Handbooks (ACI/AISC)
March 2017

(5.0.0.7)

© 2017 Trimble Solutions Corporation – part of Trimble Navigation Ltd.
Table of Contents
Wind Modeling Handbook ........................................................................................................... 1
Overview of the Wind Model method .................................................................................... 1
Clothe the structure in wind wall and roof panels ........................................................... 1
Perform the gravity design ................................................................................................... 3
Run the Wind Wizard............................................................................................................. 3
Review the wind zones .......................................................................................................... 3
Define the wind loadcases ................................................................................................... 3
Review wind zone loads ........................................................................................................ 4
Combine the wind loadcases into design combinations ................................................. 4
Perform the static design ..................................................................................................... 4
ASCE7 Wind Wizard ................................................................................................................... 4
Scope ....................................................................................................................................... 4
Limitations .............................................................................................................................. 5
Geometry ............................................................................................................................ 5
Loaded Areas ...................................................................................................................... 5
Wind Direction .................................................................................................................... 6
Design Wind Load .............................................................................................................. 6
Additional wind loads ........................................................................................................ 6
Choice of Method .................................................................................................................. 6
Applicability of the Low-Rise Building method .............................................................. 6
Low Rise Buildings - Geometry ............................................................................................ 7
Rigid Buildings of All Heights - Geometry .......................................................................... 9
Basic Wind Data ................................................................................................................... 11
Results ................................................................................................................................... 12
Wind Zones - ASCE7 Low Rise Building Method.............................................................. 12
Wind Directions ................................................................................................................ 12
Wall Zones ......................................................................................................................... 13
Roof Zones ........................................................................................................................ 13
Wind Zones - ASCE7 All Heights Method .......................................................................... 13
Wind Directions ................................................................................................................ 13
Wall Zones ......................................................................................................................... 14
Roof Zones ........................................................................................................................ 14
Wind Model Loadcases ........................................................................................................... 15
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Creating Loadcases for the Low Rise Buildings Method ................................................ 16
Adding Wind Loadcases .................................................................................................. 16
Auto generating Wind Loadcases .................................................................................. 17
Creating Loadcases for the All Heights Method .............................................................. 17
Adding Wind Loadcases .................................................................................................. 17
Auto generating Wind Loadcases .................................................................................. 18
Wind Model Load Decomposition ......................................................................................... 18
Roof Panel Load Decomposition ....................................................................................... 18
Wind Wall Panel Load Decomposition.............................................................................. 20
Decomposition Options .................................................................................................. 20
Decompose to Members ................................................................................................ 21
Decompose to Nodes ...................................................................................................... 22
Decompose to Rigid Diaphragms .................................................................................. 23
Alternative decomposition methods for complex models ............................................ 24
Simplified Wind Wall Panels ........................................................................................... 25
Application of manual wind loads ......................................................................................... 27
Simple Wind ............................................................................................................................. 28
Overview of Simple Wind ................................................................................................... 28
Simple Wind application and decomposition .................................................................. 28
Limitations of wind decomposition to diaphragms ........................................................... 30
Wind load perpendicular to disconnected diaphragms............................................. 30
Wind load parallel to disconnected diaphragms ........................................................ 34
References ................................................................................................................................ 36
Stability Requirements Handbook ............................................................................................ 39
Introduction to stability requirements ................................................................................. 39
Global second-order effects .................................................................................................. 39
Choice of analysis type (ACI/AISC) ..................................................................................... 39
Sway sensitivity assessment (ACI/AISC) ............................................................................ 40
When should a concrete building be classed as nonsway? ....................................... 40
How do I assess the worst elastic critical load factor for the building? ................... 40
Drift .................................................................................................................................... 41
Modification Factors ............................................................................................................ 42
Member second-order effects ............................................................................................... 43
Global imperfections ............................................................................................................... 43
Member imperfections ........................................................................................................... 43
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Wind drift .................................................................................................................................. 43
Overall displacement .............................................................................................................. 44
Solver Models Handbook ........................................................................................................... 45
Solver models ........................................................................................................................... 45
Working Solver Model ......................................................................................................... 45
Solver Model used for 1st Order Linear ........................................................................... 45
3D Building Analysis model ............................................................................................ 46
Solver Model used for 1st Order Non Linear .................................................................. 47
Solver Model used for 2nd Order Linear ......................................................................... 47
Solver Model used for 2nd Order Non Linear ................................................................. 48
Solver Model used for 1st Order Vibration ...................................................................... 48
Solver Model used for 2nd Order Buckling ..................................................................... 49
Solver Model used for Grillage Chasedown..................................................................... 49
Solver Model used for FE Chasedown .............................................................................. 50
Solver Model used for Load Decomposition ................................................................... 51
Refresh Solver Model .......................................................................................................... 52
Analysis objects ........................................................................................................................ 52
Solver models created for concrete members ................................................................... 53
Concrete column physical and solver models ................................................................. 53
Concrete column physical model .................................................................................. 53
Concrete column solver elements................................................................................. 54
Concrete beam physical and solver models .................................................................... 55
Concrete beam physical model ..................................................................................... 55
Concrete beam solver elements .................................................................................... 56
Rigid offsets .......................................................................................................................... 57
Rigid zones ............................................................................................................................ 57
Application of Rigid Zones .............................................................................................. 58
Rigid Zones Example 1 - fixed ended beam ................................................................. 58
Rigid Zones Example 2 - pin ended beam .................................................................... 62
Solver models created for steel and other materials ........................................................ 64
Steel column physical and solver models ........................................................................ 64
Steel column physical model ......................................................................................... 64
Steel column solver elements ........................................................................................ 64
Steel beam physical and solver models ........................................................................... 66
Steel beam physical model ............................................................................................. 66
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Steel beam solver elements ........................................................................................... 68
Steel brace physical and solver models ........................................................................... 69
Steel brace physical model ............................................................................................. 69
Steel brace solver elements ........................................................................................... 70
Inactive steel braces ........................................................................................................ 70
Tension only and compression only braces ................................................................ 70
Input method for A and V Braces .................................................................................. 70
Steel parapet post physical and solver models .............................................................. 70
Solver models created for concrete walls ............................................................................ 71
Concrete wall physical model ........................................................................................ 71
Concrete wall solver model ............................................................................................ 72
Concrete wall openings and extensions .............................................................................. 76
Concrete wall openings ...................................................................................................... 76
Limitations of wall openings .......................................................................................... 76
Analysis model applied to meshed wall panels with openings ................................ 77
Alternative model for wall openings ............................................................................. 77
Concrete wall extensions .................................................................................................... 79
Use of concrete wall extensions .................................................................................... 79
Concrete wall extension examples ............................................................................... 80
Solver models created for bearing walls.............................................................................. 84
Bearing wall physical model ........................................................................................... 85
Bearing wall solver model .............................................................................................. 85
Solver models created for slabs ............................................................................................ 87
Vertical alignment of slabs ................................................................................................. 87
Effect of slab openings on solver models ........................................................................ 88
Slab on beams solver models ............................................................................................ 89
Flat slab solver models ....................................................................................................... 89
Precast solver models ......................................................................................................... 89
Steel deck solver models .................................................................................................... 89
Timber deck solver models ................................................................................................ 89
Composite slab solver models ........................................................................................... 89
Diaphragms and floor meshing............................................................................................. 90
Diaphragm types ................................................................................................................. 90
Rigid ................................................................................................................................... 90
Semi-rigid .......................................................................................................................... 91
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Table of Contents
Diaphragm constraint and mesh type configurations ................................................... 92
Diaphragm option ............................................................................................................ 92
Decomposition ................................................................................................................. 92
Mesh 2-way Slabs in 3D Analysis ................................................................................... 93
Summary of diaphragm constraint and mesh type configurations ......................... 93
Other slab properties affecting the solver models ..................................................... 94
Mesh parameters ................................................................................................................ 95
Slab Mesh .......................................................................................................................... 95
Semi-Rigid Mesh ............................................................................................................... 95
Releases .................................................................................................................................... 95
Column Releases ................................................................................................................. 95
Wall Releases ........................................................................................................................ 96
Beam Releases ..................................................................................................................... 96
Brace Releases ..................................................................................................................... 97
Supports.................................................................................................................................... 97
Support degrees of freedom ............................................................................................. 98
Non linear spring supports ................................................................................................ 98
Partial fixity of column bases ............................................................................................. 99
Static Analysis and Design Handbook ....................................................................................101
Definitions ..............................................................................................................................101
Summary of Static Analysis-Design Processes ..................................................................102
Model validation ....................................................................................................................104
3D pre-Analysis ......................................................................................................................104
Load decomposition ..........................................................................................................105
1-way slab load decomposition ...................................................................................105
2-way slab load decomposition ...................................................................................105
Global imperfections .........................................................................................................106
Load reductions .................................................................................................................107
Pattern loading ...................................................................................................................107
3D Building Analysis ..............................................................................................................107
First Order or Second Order Analysis .........................................................................107
Linear or Non Linear Analysis ......................................................................................107
Grillage Chasedown Analysis ...............................................................................................107
FE Chasedown Analysis ........................................................................................................108
Sway sensitivity ......................................................................................................................109
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Member design ......................................................................................................................110
Steel Member Design Forces .......................................................................................110
Concrete Member Design Forces ................................................................................110
Reset Autodesign ...........................................................................................................111
Design Review ........................................................................................................................111
Comparison of solver models used in Static Analysis-Design ........................................111
Seismic Analysis and Design Handbook ................................................................................115
Introduction to Seismic Analysis and Design ....................................................................115
Definitions ...........................................................................................................................115
Code Spectra ..................................................................................................................115
Site Specific Spectra .......................................................................................................115
Base Shear Combination ..............................................................................................115
RSA Seismic Combination .............................................................................................115
Static Loadcase ...............................................................................................................116
RSA Seismic Loadcase ...................................................................................................116
RSA Torsion Loadcase ...................................................................................................116
Fundamental Period (T) ................................................................................................116
Level Seismic Weight .....................................................................................................116
Effective Seismic Weight ...............................................................................................116
Seismic Base Shear ........................................................................................................116
Square root of Summation of Square (SRSS) .............................................................116
Complete Quadratic Combination (CQC) ...................................................................117
Cross Modal Coefficient ................................................................................................117
Overview .............................................................................................................................117
Seismic Wizard ...................................................................................................................119
Vertical and Horizontal Irregularities ..............................................................................119
Torsion ................................................................................................................................119
Vibration Analysis ..............................................................................................................120
% of Gravity Load Method ................................................................................................120
Equivalent Lateral Force Method ....................................................................................120
Response Spectrum Analysis Method ............................................................................121
Summary of RSA Seismic Analysis Processes ............................................................121
Seismic Drift ........................................................................................................................122
Design Coefficients and Factors ......................................................................................122
Limitations of Seismic Design ..............................................................................................122
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Specific limitations of steel seismic design ................................................................123
Seismic Force Resisting Systems .........................................................................................123
Available SFRS types ..........................................................................................................123
SFRS types included for steel members .....................................................................123
SFRS types available for concrete members ..............................................................124
SFRS types excluded ......................................................................................................124
Members allowed in the SFRS .........................................................................................124
Assigning members to the SFRS ......................................................................................125
Special Moment Frames - assigning connection types at steel beam ends .............125
Validation of the SFRS .......................................................................................................125
Auto design of SFRS members .........................................................................................126
Seismic Design Methods ......................................................................................................126
Seismic analysis and conventional design .....................................................................126
ELF seismic analysis and conventional design ..........................................................126
RSA seismic analysis and conventional design ..........................................................127
Seismic analysis and seismic design ...............................................................................128
ELF seismic analysis and seismic design ....................................................................128
RSA seismic analysis and seismic design ...................................................................129
ASCE7 Seismic Wizard ...........................................................................................................130
Starting the Wizard ........................................................................................................131
Site Specific Spectra .......................................................................................................131
Base Information Page ..................................................................................................131
Structure Irregularities Page ........................................................................................132
Fundamental Period Page ............................................................................................133
Seismic Force Resisting System Page..........................................................................134
Effective Seismic Weight Page ......................................................................................134
Seismic Loading Page ....................................................................................................134
Finishing the Seismic Wizard ........................................................................................135
Concrete Design Handbook .....................................................................................................137
Design Concrete ....................................................................................................................137
Features common to concrete beam, column and wall design..................................137
Gravity or Static Design? ...............................................................................................137
Analysis types performed in the Design Concrete process .....................................137
Pre-design considerations ............................................................................................138
Nominal cover ................................................................................................................138
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Assume cracked .............................................................................................................139
Reinforcement Parameters ..........................................................................................139
Design and detailing groups (concrete) .........................................................................140
Why use concrete design and detailing groups? .......................................................140
What happens in the group design process? ............................................................141
Concrete design group requirements ........................................................................141
Detailing group requirements .....................................................................................142
Group management ......................................................................................................143
How is grouped design and detailing de-activated for concrete members? ........144
Typical Design Concrete workflow ..................................................................................144
Set up Pattern Loading .................................................................................................145
Set all beams columns and walls into autodesign mode.........................................146
Review beam and column design groups ..................................................................146
Review beam, column and wall design parameters and reinforcement settings 147
Perform the concrete design .......................................................................................147
Review the design status and ratios ...........................................................................147
Create Drawings and Quantity Estimations ...............................................................148
Print Calculations ...........................................................................................................148
Reviewing Design Concrete and refining the design of individual members ...........149
How do I view results for a single concrete member (without re-selecting steel)?
..........................................................................................................................................149
How do I re-select steel for a single concrete member and then view its results?
..........................................................................................................................................149
Features of concrete beam design .....................................................................................150
Analysis types used for concrete beam design .............................................................150
Autodesign (concrete beam) ............................................................................................150
Deflection control ..............................................................................................................151
Use of beam flanges ..........................................................................................................153
Load reductions .................................................................................................................156
Longitudinal reinforcement .............................................................................................156
Bar layers ........................................................................................................................157
Longitudinal Reinforcement Patterns Library ...........................................................158
Longitudinal Reinforcement Regions ..........................................................................161
Relationship between Reinforcement Patterns and Design Regions ....................162
Shear reinforcement .........................................................................................................164
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Shear Reinforcement Shapes Library .........................................................................164
Shear Reinforcement Patterns Library .......................................................................165
Shear Reinforcement Regions .....................................................................................165
Features of concrete column design ..................................................................................166
Autodesign (concrete column) .........................................................................................167
Section .................................................................................................................................167
Slenderness ........................................................................................................................168
Stiffness ...............................................................................................................................169
Load reductions .................................................................................................................169
Stacks and reinforcement lifts .........................................................................................170
Column design forces .......................................................................................................171
Features of concrete wall design ........................................................................................171
Autodesign (concrete wall) ...............................................................................................171
Slenderness ........................................................................................................................171
Stiffness ...............................................................................................................................172
Reinforcement ....................................................................................................................172
Load reductions .................................................................................................................172
Stacks and reinforcement lifts .........................................................................................173
Wall design forces ..............................................................................................................174
Concrete slab design .............................................................................................................174
Features of concrete slab analysis and design ..............................................................174
Analysis types used for concrete slab design ............................................................174
Concrete slab load decomposition .............................................................................175
Slab on beam idealized panels ....................................................................................175
Combined slab and patch reinforcement ..................................................................177
Typical flat slab design procedure ..................................................................................178
Flat slab design example ..............................................................................................178
Set up Pattern Loading .................................................................................................179
Design All .........................................................................................................................180
Consider Deflection (for Flat slabs) .............................................................................180
Select a Level ..................................................................................................................181
Add Patches ....................................................................................................................181
Design Panels .................................................................................................................182
Review/Optimise Panel Design ....................................................................................183
Design Patches ...............................................................................................................184
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