Dr. Pramin Norachan
Manager, Structural Engineering Unit, AIT Consulting
Affiliated Faculty, Structural Engineering, AIT
CE72.32 Tall Buildings
Modeling, Analysis and Design Tall
Buildings using Commercial Finite
Element Programs
1. Introduction
2. Commercial Finite Element
Software
3. Basic Concepts of Finite
Element Software
4. Modeling, Analysis and Design
of Tall Buildings
5. Sequential Construction Cases
6. Wind Loads
7. Seismic Loads
8. Piles, Spring Supports and
Foundations
9. Design
Presentation Outline
To introduce commercial finite
element programs used for
analysis and design of tall
buildings.
To provide an understanding of the
concepts, techniques and
technologies in modeling, analysis
and design of RC tall buildings
using FE programs.
Objectives
Dr. Pramin Norachan 5
Structural Mechanics
Statics Dynamics
Rigid Body Deformable Body
Statics
(Rigid Body)
Mechanics of
Materials
Structural Analysis
Matrix Structural
Analysis
Continuum or
Advanced
Mechanics of
Materials
Advanced Structures
Dynamics
(Rigid Body)
Structural Dynamics
Earthquake EngineeringWind EngineeringFinite Element
Commercial FE programs (SAP2000, ETABS, STAAD Pro, ANSYS, ABAQUS, etc.)
Rigid Body Deformable Body
UndergraduateGraduate
RC,PC, Timber, and
Steel Designs
Adv. RC,PC, and
Steel Designs
Dr. Pramin Norachan 6
STRUCTURAL ENGINEERING IS
THE ART OF USING MATERIALS
That Have Properties Which Can Only Be Estimated
TO BUILD REAL STRUCTURES
That Can Only Be Approximately Analyzed
TO WITHSTAND FORCES
That Are Not Accurately Known
SO THAT OUR RESPONSIBILITY WITH RESPECT TO
PUBLIC SAFETY IS SATISFIED.
Adapted From An Unknown Author
Edward L. Wilson
Professor Emeritus of Structural Engineering (The original developer of CAL, SAP and ETABS series of computer programs)
University of California at Berkeley
Three-Dimensional Static and Dynamic Analysis of Structures
A Physical Approach With Emphasis on Earthquake Engineering
Dr. Pramin Norachan 7
Tall Building
2 Story House
Stadium
Offshore Structure
Warehouse
Bridge
Dr. Pramin Norachan 8
Architectural
Functional Plans
Structural System
Trial Sections
Modeling
Analysis
Revise Sections
Member Design
Acceptable
Connection Design
Detailing
Final Design
Yes
No
Conceptual Design
Modeling and Analysis
Design and Detailing
Dr. Pramin Norachan 9
Dr. Pramin Norachan 10
Dr. Pramin Norachan 11
Dr. Pramin Norachan 12
MahaNakhon Tower (314 m)Baiyoke Tower II (304 m)
Dr. Pramin Norachan 13
Dr. Pramin Norachan Dr. Pramin Norachan
Researches Structural Analysis and Design
ABAQUS SAP2000, ETABS, PERFORM3D,
CSIbridge
ANSYS STAAD Pro
ADINA MIDAS
DIANA ROBOT
NASTRAN SASC
15
Dr. Pramin Norachan 16
Structural and Earthquake Engineering Software
Computers and Structures, Inc. (CSI)
www.csiamerica.com
Dr. Pramin Norachan 17
Dr. Pramin Norachan 18
Integrated software for structural analysis and design
Dr. Pramin Norachan 19
Integrated software for structural analysis and design
Ferris wheel
Dr. Pramin Norachan 20
Dr. Pramin Norachan 21
Dr. Pramin Norachan 22
Integrated analysis, design and drafting of building systems
Dr. Pramin Norachan 23
Dr. Pramin Norachan 24
Dr. Pramin Norachan 25
Integrated 3D bridge design software
Dr. Pramin Norachan 26
Dr. Pramin Norachan 27
Dr. Pramin Norachan 28
Nonlinear analysis and performance
assessment for 3D structures
Dr. Pramin Norachan 29
Dr. Pramin Norachan 30
Dr. Pramin Norachan 31
Integrated design of flat slabs, foundation and spread footing
Dr. Pramin Norachan 32
Dr. Pramin Norachan 33
Dr. Pramin Norachan 34
Design of simple and complex reinforced concrete columns
How do the FE programs work?
Creating the model
(Pre-process)
Reporting results
(Post-process)
Analysis of the
Structure (FEM)
A, E
A, E
Displacements
Stresses
1 2 3
36
1) Line Elements : Truss and Beam Elements (1D, 2D, 3D)
2) Surface Elements : Plane Stress, Plane Strain, Plate and
Shell Elements (2D, 3D)
3) Solid Elements (3D)
37
Element Types
Real Structures
Solid Model 3D Shell-Frame 3D Frame
2D Frame
There are various ways to model a real structure
2D
3D
38
Concepts of Structural Modeling
Cable Structures
Line Structures
Surface Structures
Solid Structures
- Cable Stayed
- 2D/3D Trusses
- 2D/3D Frames
- Plate, Shell
- Plane Stress
39
Structural Types
Tall Buildings Columns : Frame elements
Which types of elements will we choose to
model structures?
Floors : Plate or Shell elements
Suspension
bridges
Main Towers : Frame elements
Decks : Frame, Plate or Shell elements
Cables : cable elements
(Line structures)
(Surface structures)
(Line structures)
(Line structures)
(Line or surface structures)
Beams : Frame elements
(Line structures)
40
Dr. Pramin Norachan 41
EXCITATION STRUCTURE RESPONSES
Loads
- Gravity (DL, LL)
- Wind
- Earthquake
Vibrations
Settlements
Thermal Changes
(Static of Dynamic) (Elastic or Inelastic)
F = K × Δ
Displacements
Strains
Stresses
Stress Resultants
(Internal Forces)
- Axial Force
- Shear
- Moment
(Linear or Nonlinear)
DESIGN
Dr. Pramin Norachan 42
EXCITATION STRUCTURE RESPONSES
(Loads) (Stiffness)
F = K × Δ
(Deformation)
F
F
K
K
Δ
Δ
F K 
F
K
 
Dr. Pramin Norachan Dr. Pramin Norachan
Gravity Load Lateral Load
Moment
Shear
Moment
Shear
F
F
F
F
F
F
F
F
43
45
46
Create the structure Assign Supports Assign Material
Properties and
Section
Assign Loads
Hinge Roller
6.00
47
Assign Supports Perform Analysis Perform Design
3.00 3.00
3.00
3.00
3.00
3.00
stress
strain
E, v
Concrete
Steel
(Concrete,
Steel, Others)
W
W
W
W
F
F
F
F
Fix Fix Fix
M(+) M(+)
M(-)M(-) M(-)
Draw Grid Line Define Material
Properties
Define Sections Draw the Structure
Assign Loads
1 2 3 4
5 6 7 8
1 2,3 4 5,6 7 8
48
x
y
Draw Grid Line1
49
xy
z
Draw Grid Line1
50
E, v
Define Material
Properties
2
51
Define Sections3
52
Define Sections3
53
Line Element Area Element
Draw the Structure4
54
Assign Supports5
55
Point Load
Line Load
Area Load
Assign Loads6
56
Perform Analysis7
57
Perform Analysis7
58
Perform Design8
59
Perform Design8
Sequential Construction
Cases
61
• Static Load Cases
- Dead Load (Sequential Construction : D)
- Live Load (L)
- Wind Load (W)
- Equivalent Static Load Cases (E)
Load cases are defined by the user and used for
analysis purpose only
• Dynamic Load Cases
- Response Spectrum Load Cases (E)
- Time History Load Cases (E)
Load Cases
62
Sequential Construction Cases
Deflection
63
Sequential Construction Cases
Moment
89.843.5
Linear Sequential
64
Sequential Construction Cases
65
Sequential Construction Cases
66
• Static Load Cases
- Dead Load (Sequential Construction : D)
- Live Load (L)
- Wind Load (W)
- Equivalent Static Load Cases (E)
Load cases are defined by the user and used for
analysis purpose only
• Dynamic Load Cases
- Response Spectrum Load Cases (E)
- Time History Load Cases (E)
Load Cases
Wind Load
Dr. Pramin Norachan 68
Severe damage to an office building caused by Hurricane Andrew (1992)
Dr. Pramin Norachan 69
Torsional Flutter of the Tacoma Narrows Bridge (1940)
Dr. Pramin Norachan 70
Dr. Pramin Norachan 71
Dr. Pramin Norachan 72
Dr. Pramin Norachan 73
Dr. Pramin Norachan 74
Dr. Pramin Norachan 75
Vertical variation of external wind pressure coefficient Cp with respect to plan aspect
ratio L/B.
Dr. Pramin Norachan 76
• Static Load Cases
- Dead Load (Sequential Construction : D)
- Live Load (L)
- Wind Load (W)
- Equivalent Static Load Cases (E)
Load cases are defined by the user and used for
analysis purpose only
• Dynamic Load Cases
- Response Spectrum Load Cases (E)
- Time History Load Cases (E)
77
Load Cases
Dr. Pramin Norachan 78
Pressure loads on
Surrounding areas
Point loads at the
center of diaphragms
Wind Pressure Point loads at
column nodes
1 2 3
79
Point loads at the
center of diaphragms
2
80
Point loads at the
center of diaphragms
2
81
Pressure loads on
Surrounding areas
3
82
Pressure loads on
Surrounding areas
3
83
Pressure loads on
Surrounding areas
3
84
Pressure loads on
Surrounding areas
3
Seismic Load
Dr. Pramin Norachan 86
A reinforced concrete house in Chiang Rai
collapsed due to a strong earthquake event.
Dr. Pramin Norachan 87
The other wood house which is
located nearby the first RC
house can stand over the
earthquake event.
There was no structural
damage which could be
observed.
The first reason is possible due
to the light weight (mass) of the
wood building, which produced
the less seismic force. The
second reason is due to the
wood structure is very flexible,
which can perform with large
deformation.
Dr. Pramin Norachan 88
m
2
k
u
gu
2
k c
(a) Moving Base
m
2
k
u
( ) ( )eff gp t mu t 
2
k c
(b) Stationary Base
( ) ( )eff gp t mu t 
Effective Earthquake Force, ( )effp t
0 ?m 
0 ?gu 
89
Seismic Load
1) Equivalent Statics 2) Response Spectrum 3) Time History
- Static approach
- Simple regular structures
- Low-to-medium-rise
building
- Dynamic approach
- All structures
- Suitable for structural
design
- Dynamic approach
- All structures
- The most accurate analysis
- Both linear and nonlinear
- Based on fundamental
mode
- Linear analysis
- Linear analysis - Take time for analysis
- Difficult to combine the
results
• Static Load Cases
- Dead Load (Sequential Construction : D)
- Live Load (L)
- Wind Load (W)
- Equivalent Static Load Cases (E)
Load cases are defined by the user and used for
analysis purpose only
• Dynamic Load Cases
- Response Spectrum Load Cases (E)
- Time History Load Cases (E)
90
Load Cases
91
• Static Load Cases
- Dead Load (Sequential Construction : D)
- Live Load (L)
- Wind Load (W)
- Equivalent Static Load Cases (E)
Load cases are defined by the user and used for
analysis purpose only
• Dynamic Load Cases
- Response Spectrum Load Cases (E)
- Time History Load Cases (E)
92
Load Cases
93
94
95
• Static Load Cases
- Dead Load (Sequential Construction : D)
- Live Load (L)
- Wind Load (W)
- Equivalent Static Load Cases (E)
Load cases are defined by the user and used for
analysis purpose only
• Dynamic Load Cases
- Response Spectrum Load Cases (E)
- Time History Load Cases (E)
96
Load Cases
97
98
Piles, Spring Supports
and Foundations
100
The fist model is used for finding number of piles and preliminary
designing the foundations based on loads at the supports.
The model with Normal Supports
The Model with Piles
The second model is included both piles and
foundations. The internal forces of piles which are used
to design pile detailing can be known by perform the
linear analysis for this model. 101
Equivalent Spring Supports
Actual pile
embedded in soil
102
𝐾𝑣 = 𝐹𝑣 ∆ 𝑣
𝐾ℎ = 𝐹ℎ ∆ℎ
𝐹𝑣
𝐹ℎ
∆ 𝑣
∆ℎ
𝐾𝑣
𝐾ℎ
Soil represented
by lateral spring
Pile modeled
with lateral
spring
Pile deformation
under applied
loads
𝐾 = 𝐾𝑠 × 𝐴ℎ
𝐾
The Model with Spring Supports
This model can be used for foundation design by
exporting the foundation floor to SAFE, and it will be
used for analysis and design in the remaining works.
103
Design
Programs for Structural Design
- Beams
- Columns
- Shear Walls
- Arbitrary shape
Columns
- Composite Columns
- Slabs
- Post tension
Slabs
- Foundations
Structural Modeling
Siri@Sukhumvit
Design for Parts of the Structures
Water tank
Mat
Foundation
Floor
Transfer
beam
Roof
Structures
Swimming
pool
Guard house
Project road
Fence
Design for Parts of the Structures
109
Load Combinations
Dr. Pramin Norachan 110
Demand Force (D) ≤ Structural Capacity (C)
u nF F
1.0u
n
FD
C F
 
Strength Design Method (SDM)
Dr. Pramin Norachan 111
No. Load Combinations Description
1 1.4 DL Dead load
2 1.2 DL + 1.6 LL Gravity load
3 1.2 DL + 1.0 LL + 1.6 WL Wind load (compression)
4 0.9 DL + 1.6 WL Wind load (tension)
5 1.2 DL + 1.0 LL + 1.0 EQ Seismic load (compression)
6 0.9 DL + 1.0 EQ Seismic load (tension)
ACI 318-08 (Strength Design Method) : SDM
Load factor on the live load LL in No. 3 and 5 shall be permitted to be reduced
to 0.5 except for all areas where LL is greater than 500 kg/m2.
Dr. Pramin Norachan 112
No. Load Combinations Description
1 DL Dead load
2 DL + LL Gravity load
3 DL + 0.75 LL + 0.75 (0.6 WL) Wind load (compression)
4 0.6 DL + 0.6 WL Wind load (tension)
5 DL + 0.75 LL + 0.75 (0.7 EQ) Seismic load (compression)
6 0.6 DL + 0.7 EQ Seismic load (tension)
ASCE 7-10 (Allowable Stress Design)
Dr. Pramin Norachan 113
Member Items Demand (D) Capacity (C) Design Concept
Pile Number of
piles
Service load
combinations
(including footing
weight)
Ultimate pile load → Calculate from
soil report
Safe load =
Ultimate load
SF
SF ≈ 2.0 – 2.5
RC Design Ultimate load
combinations
(including footing
weight)
D
n
C

( )n
n
n
PMM
F
V



 

  


Compression
Tension 1.0u
n
FD
C F
 
F
uF
Dr. Pramin Norachan 114
Member Items Demand (D) Capacity (C) Design Concept
Footing RC design Ultimate load
combinations
(including footing
weight)
Column
above
footing
RC design Ultimate load
combinations
(including footing
weight)
n
n
n
M
F
V





 


1.0u
n
FD
C F
 
uF
uF
1.0u
n
FD
C F
 One-way shear
Punching shear
n
n
PMM
F
V



 

  


Compression
Tension
Dr. Pramin Norachan 115
Member Items Demand (D) Capacity (C) Design Concept
Beam/
Stair
RC design Ultimate load
combinations
Column/
Shear
wall
RC design Ultimate load
combinations
One-way
slab
RC design Ultimate load
combinations
Two-way
slab
RC design Ultimate load
combinations
n
n
n
M
F
V




 

1.0u
n
FD
C F
 
uF
uF
1.0u
n
FD
C F
 
n
n
PMM
F
V



 

  


Compression
Tension
uF
n
n
n
M
F
V




 

1.0u
n
FD
C F
 
uF
n
n
n
M
F
V





 


1.0u
n
FD
C F
 One-way shear
Punching shear
Dr. Pramin Norachan 116
2
n s y
a
M A f d 
 
  
  0.85 '
s y
c
A f
a
f b

• Flexural Design
• Shear Design
n c sV V V   
'
0.53c cV f bd 
v y
s
A f d
V
s
 
 
  
 
Dr. Pramin Norachan 117
Dr. Pramin Norachan
Manager, Structural Engineering Unit, AIT Consulting
Affiliated Faculty, Structural Engineering, AIT
Thank You

CE 72.32 (January 2016 Semester): Lecture 1b: Analysis and Design of Tall Buildings using Commercial FE Programs

  • 1.
    Dr. Pramin Norachan Manager,Structural Engineering Unit, AIT Consulting Affiliated Faculty, Structural Engineering, AIT CE72.32 Tall Buildings Modeling, Analysis and Design Tall Buildings using Commercial Finite Element Programs
  • 2.
    1. Introduction 2. CommercialFinite Element Software 3. Basic Concepts of Finite Element Software 4. Modeling, Analysis and Design of Tall Buildings 5. Sequential Construction Cases 6. Wind Loads 7. Seismic Loads 8. Piles, Spring Supports and Foundations 9. Design Presentation Outline
  • 3.
    To introduce commercialfinite element programs used for analysis and design of tall buildings. To provide an understanding of the concepts, techniques and technologies in modeling, analysis and design of RC tall buildings using FE programs. Objectives
  • 5.
    Dr. Pramin Norachan5 Structural Mechanics Statics Dynamics Rigid Body Deformable Body Statics (Rigid Body) Mechanics of Materials Structural Analysis Matrix Structural Analysis Continuum or Advanced Mechanics of Materials Advanced Structures Dynamics (Rigid Body) Structural Dynamics Earthquake EngineeringWind EngineeringFinite Element Commercial FE programs (SAP2000, ETABS, STAAD Pro, ANSYS, ABAQUS, etc.) Rigid Body Deformable Body UndergraduateGraduate RC,PC, Timber, and Steel Designs Adv. RC,PC, and Steel Designs
  • 6.
    Dr. Pramin Norachan6 STRUCTURAL ENGINEERING IS THE ART OF USING MATERIALS That Have Properties Which Can Only Be Estimated TO BUILD REAL STRUCTURES That Can Only Be Approximately Analyzed TO WITHSTAND FORCES That Are Not Accurately Known SO THAT OUR RESPONSIBILITY WITH RESPECT TO PUBLIC SAFETY IS SATISFIED. Adapted From An Unknown Author Edward L. Wilson Professor Emeritus of Structural Engineering (The original developer of CAL, SAP and ETABS series of computer programs) University of California at Berkeley Three-Dimensional Static and Dynamic Analysis of Structures A Physical Approach With Emphasis on Earthquake Engineering
  • 7.
    Dr. Pramin Norachan7 Tall Building 2 Story House Stadium Offshore Structure Warehouse Bridge
  • 8.
    Dr. Pramin Norachan8 Architectural Functional Plans Structural System Trial Sections Modeling Analysis Revise Sections Member Design Acceptable Connection Design Detailing Final Design Yes No Conceptual Design Modeling and Analysis Design and Detailing
  • 9.
  • 10.
  • 11.
  • 12.
    Dr. Pramin Norachan12 MahaNakhon Tower (314 m)Baiyoke Tower II (304 m)
  • 13.
  • 15.
    Dr. Pramin NorachanDr. Pramin Norachan Researches Structural Analysis and Design ABAQUS SAP2000, ETABS, PERFORM3D, CSIbridge ANSYS STAAD Pro ADINA MIDAS DIANA ROBOT NASTRAN SASC 15
  • 16.
    Dr. Pramin Norachan16 Structural and Earthquake Engineering Software Computers and Structures, Inc. (CSI) www.csiamerica.com
  • 17.
  • 18.
    Dr. Pramin Norachan18 Integrated software for structural analysis and design
  • 19.
    Dr. Pramin Norachan19 Integrated software for structural analysis and design Ferris wheel
  • 20.
  • 21.
  • 22.
    Dr. Pramin Norachan22 Integrated analysis, design and drafting of building systems
  • 23.
  • 24.
  • 25.
    Dr. Pramin Norachan25 Integrated 3D bridge design software
  • 26.
  • 27.
  • 28.
    Dr. Pramin Norachan28 Nonlinear analysis and performance assessment for 3D structures
  • 29.
  • 30.
  • 31.
    Dr. Pramin Norachan31 Integrated design of flat slabs, foundation and spread footing
  • 32.
  • 33.
  • 34.
    Dr. Pramin Norachan34 Design of simple and complex reinforced concrete columns
  • 36.
    How do theFE programs work? Creating the model (Pre-process) Reporting results (Post-process) Analysis of the Structure (FEM) A, E A, E Displacements Stresses 1 2 3 36
  • 37.
    1) Line Elements: Truss and Beam Elements (1D, 2D, 3D) 2) Surface Elements : Plane Stress, Plane Strain, Plate and Shell Elements (2D, 3D) 3) Solid Elements (3D) 37 Element Types
  • 38.
    Real Structures Solid Model3D Shell-Frame 3D Frame 2D Frame There are various ways to model a real structure 2D 3D 38 Concepts of Structural Modeling
  • 39.
    Cable Structures Line Structures SurfaceStructures Solid Structures - Cable Stayed - 2D/3D Trusses - 2D/3D Frames - Plate, Shell - Plane Stress 39 Structural Types
  • 40.
    Tall Buildings Columns: Frame elements Which types of elements will we choose to model structures? Floors : Plate or Shell elements Suspension bridges Main Towers : Frame elements Decks : Frame, Plate or Shell elements Cables : cable elements (Line structures) (Surface structures) (Line structures) (Line structures) (Line or surface structures) Beams : Frame elements (Line structures) 40
  • 41.
    Dr. Pramin Norachan41 EXCITATION STRUCTURE RESPONSES Loads - Gravity (DL, LL) - Wind - Earthquake Vibrations Settlements Thermal Changes (Static of Dynamic) (Elastic or Inelastic) F = K × Δ Displacements Strains Stresses Stress Resultants (Internal Forces) - Axial Force - Shear - Moment (Linear or Nonlinear) DESIGN
  • 42.
    Dr. Pramin Norachan42 EXCITATION STRUCTURE RESPONSES (Loads) (Stiffness) F = K × Δ (Deformation) F F K K Δ Δ F K  F K  
  • 43.
    Dr. Pramin NorachanDr. Pramin Norachan Gravity Load Lateral Load Moment Shear Moment Shear F F F F F F F F 43
  • 45.
  • 46.
    46 Create the structureAssign Supports Assign Material Properties and Section Assign Loads Hinge Roller 6.00
  • 47.
    47 Assign Supports PerformAnalysis Perform Design 3.00 3.00 3.00 3.00 3.00 3.00 stress strain E, v Concrete Steel (Concrete, Steel, Others) W W W W F F F F Fix Fix Fix M(+) M(+) M(-)M(-) M(-) Draw Grid Line Define Material Properties Define Sections Draw the Structure Assign Loads 1 2 3 4 5 6 7 8 1 2,3 4 5,6 7 8
  • 48.
  • 49.
  • 50.
  • 51.
  • 52.
  • 53.
    53 Line Element AreaElement Draw the Structure4
  • 54.
  • 55.
    55 Point Load Line Load AreaLoad Assign Loads6
  • 56.
  • 57.
  • 58.
  • 59.
  • 60.
  • 61.
    61 • Static LoadCases - Dead Load (Sequential Construction : D) - Live Load (L) - Wind Load (W) - Equivalent Static Load Cases (E) Load cases are defined by the user and used for analysis purpose only • Dynamic Load Cases - Response Spectrum Load Cases (E) - Time History Load Cases (E) Load Cases
  • 62.
  • 63.
  • 64.
  • 65.
  • 66.
    66 • Static LoadCases - Dead Load (Sequential Construction : D) - Live Load (L) - Wind Load (W) - Equivalent Static Load Cases (E) Load cases are defined by the user and used for analysis purpose only • Dynamic Load Cases - Response Spectrum Load Cases (E) - Time History Load Cases (E) Load Cases
  • 67.
  • 68.
    Dr. Pramin Norachan68 Severe damage to an office building caused by Hurricane Andrew (1992)
  • 69.
    Dr. Pramin Norachan69 Torsional Flutter of the Tacoma Narrows Bridge (1940)
  • 70.
  • 71.
  • 72.
  • 73.
  • 74.
  • 75.
    Dr. Pramin Norachan75 Vertical variation of external wind pressure coefficient Cp with respect to plan aspect ratio L/B.
  • 76.
  • 77.
    • Static LoadCases - Dead Load (Sequential Construction : D) - Live Load (L) - Wind Load (W) - Equivalent Static Load Cases (E) Load cases are defined by the user and used for analysis purpose only • Dynamic Load Cases - Response Spectrum Load Cases (E) - Time History Load Cases (E) 77 Load Cases
  • 78.
    Dr. Pramin Norachan78 Pressure loads on Surrounding areas Point loads at the center of diaphragms Wind Pressure Point loads at column nodes 1 2 3
  • 79.
    79 Point loads atthe center of diaphragms 2
  • 80.
    80 Point loads atthe center of diaphragms 2
  • 81.
  • 82.
  • 83.
  • 84.
  • 85.
  • 86.
    Dr. Pramin Norachan86 A reinforced concrete house in Chiang Rai collapsed due to a strong earthquake event.
  • 87.
    Dr. Pramin Norachan87 The other wood house which is located nearby the first RC house can stand over the earthquake event. There was no structural damage which could be observed. The first reason is possible due to the light weight (mass) of the wood building, which produced the less seismic force. The second reason is due to the wood structure is very flexible, which can perform with large deformation.
  • 88.
    Dr. Pramin Norachan88 m 2 k u gu 2 k c (a) Moving Base m 2 k u ( ) ( )eff gp t mu t  2 k c (b) Stationary Base ( ) ( )eff gp t mu t  Effective Earthquake Force, ( )effp t 0 ?m  0 ?gu 
  • 89.
    89 Seismic Load 1) EquivalentStatics 2) Response Spectrum 3) Time History - Static approach - Simple regular structures - Low-to-medium-rise building - Dynamic approach - All structures - Suitable for structural design - Dynamic approach - All structures - The most accurate analysis - Both linear and nonlinear - Based on fundamental mode - Linear analysis - Linear analysis - Take time for analysis - Difficult to combine the results
  • 90.
    • Static LoadCases - Dead Load (Sequential Construction : D) - Live Load (L) - Wind Load (W) - Equivalent Static Load Cases (E) Load cases are defined by the user and used for analysis purpose only • Dynamic Load Cases - Response Spectrum Load Cases (E) - Time History Load Cases (E) 90 Load Cases
  • 91.
  • 92.
    • Static LoadCases - Dead Load (Sequential Construction : D) - Live Load (L) - Wind Load (W) - Equivalent Static Load Cases (E) Load cases are defined by the user and used for analysis purpose only • Dynamic Load Cases - Response Spectrum Load Cases (E) - Time History Load Cases (E) 92 Load Cases
  • 93.
  • 94.
  • 95.
  • 96.
    • Static LoadCases - Dead Load (Sequential Construction : D) - Live Load (L) - Wind Load (W) - Equivalent Static Load Cases (E) Load cases are defined by the user and used for analysis purpose only • Dynamic Load Cases - Response Spectrum Load Cases (E) - Time History Load Cases (E) 96 Load Cases
  • 97.
  • 98.
  • 99.
  • 100.
    100 The fist modelis used for finding number of piles and preliminary designing the foundations based on loads at the supports. The model with Normal Supports
  • 101.
    The Model withPiles The second model is included both piles and foundations. The internal forces of piles which are used to design pile detailing can be known by perform the linear analysis for this model. 101
  • 102.
    Equivalent Spring Supports Actualpile embedded in soil 102 𝐾𝑣 = 𝐹𝑣 ∆ 𝑣 𝐾ℎ = 𝐹ℎ ∆ℎ 𝐹𝑣 𝐹ℎ ∆ 𝑣 ∆ℎ 𝐾𝑣 𝐾ℎ Soil represented by lateral spring Pile modeled with lateral spring Pile deformation under applied loads 𝐾 = 𝐾𝑠 × 𝐴ℎ 𝐾
  • 103.
    The Model withSpring Supports This model can be used for foundation design by exporting the foundation floor to SAFE, and it will be used for analysis and design in the remaining works. 103
  • 104.
  • 105.
    Programs for StructuralDesign - Beams - Columns - Shear Walls - Arbitrary shape Columns - Composite Columns - Slabs - Post tension Slabs - Foundations
  • 106.
  • 107.
    Design for Partsof the Structures Water tank Mat Foundation Floor Transfer beam Roof Structures
  • 108.
  • 109.
  • 110.
    Dr. Pramin Norachan110 Demand Force (D) ≤ Structural Capacity (C) u nF F 1.0u n FD C F   Strength Design Method (SDM)
  • 111.
    Dr. Pramin Norachan111 No. Load Combinations Description 1 1.4 DL Dead load 2 1.2 DL + 1.6 LL Gravity load 3 1.2 DL + 1.0 LL + 1.6 WL Wind load (compression) 4 0.9 DL + 1.6 WL Wind load (tension) 5 1.2 DL + 1.0 LL + 1.0 EQ Seismic load (compression) 6 0.9 DL + 1.0 EQ Seismic load (tension) ACI 318-08 (Strength Design Method) : SDM Load factor on the live load LL in No. 3 and 5 shall be permitted to be reduced to 0.5 except for all areas where LL is greater than 500 kg/m2.
  • 112.
    Dr. Pramin Norachan112 No. Load Combinations Description 1 DL Dead load 2 DL + LL Gravity load 3 DL + 0.75 LL + 0.75 (0.6 WL) Wind load (compression) 4 0.6 DL + 0.6 WL Wind load (tension) 5 DL + 0.75 LL + 0.75 (0.7 EQ) Seismic load (compression) 6 0.6 DL + 0.7 EQ Seismic load (tension) ASCE 7-10 (Allowable Stress Design)
  • 113.
    Dr. Pramin Norachan113 Member Items Demand (D) Capacity (C) Design Concept Pile Number of piles Service load combinations (including footing weight) Ultimate pile load → Calculate from soil report Safe load = Ultimate load SF SF ≈ 2.0 – 2.5 RC Design Ultimate load combinations (including footing weight) D n C  ( )n n n PMM F V            Compression Tension 1.0u n FD C F   F uF
  • 114.
    Dr. Pramin Norachan114 Member Items Demand (D) Capacity (C) Design Concept Footing RC design Ultimate load combinations (including footing weight) Column above footing RC design Ultimate load combinations (including footing weight) n n n M F V          1.0u n FD C F   uF uF 1.0u n FD C F  One-way shear Punching shear n n PMM F V            Compression Tension
  • 115.
    Dr. Pramin Norachan115 Member Items Demand (D) Capacity (C) Design Concept Beam/ Stair RC design Ultimate load combinations Column/ Shear wall RC design Ultimate load combinations One-way slab RC design Ultimate load combinations Two-way slab RC design Ultimate load combinations n n n M F V        1.0u n FD C F   uF uF 1.0u n FD C F   n n PMM F V            Compression Tension uF n n n M F V        1.0u n FD C F   uF n n n M F V          1.0u n FD C F  One-way shear Punching shear
  • 116.
    Dr. Pramin Norachan116 2 n s y a M A f d         0.85 ' s y c A f a f b  • Flexural Design • Shear Design n c sV V V    ' 0.53c cV f bd  v y s A f d V s         
  • 117.
  • 118.
    Dr. Pramin Norachan Manager,Structural Engineering Unit, AIT Consulting Affiliated Faculty, Structural Engineering, AIT Thank You