Wind Resistant Design AIJ Recommendations for Wind Loads on ...

Lecture 6
<strong>Wind</strong> <strong>Resistant</strong> <strong>Design</strong>
<strong>AIJ</strong> <strong>Recommendations</strong> <strong>for</strong>
<strong>Wind</strong> <strong>Loads</strong> on Buildings
Tokyo Polytechnic University
The 21st Century Center of Excellence Program
Yukio Tamura
Background
• Building Standard Law of Japan
(BSLJ) --- Minimum building design
requirements
- completely revised in 2000
- Per<strong>for</strong>mance
Based
<strong>Design</strong>
(PBD)
• <strong>AIJ</strong> <strong>Recommendations</strong> <strong>for</strong> <strong>Loads</strong> on
Buildings (<strong>AIJ</strong>-RLB
RLB) 1993
- to be revised in 2004
1

Major Revisions
• Introduction of the wind directionality
ity
factor (8 wind directions);
• Explicit introduction of wind load
combinations;
• Correction and addition of topographic
effects;
• Substantial fulfillment of aerodynamic
shape factors
<strong>Wind</strong> Load Estimation
in <strong>AIJ</strong>-RLB
Low-rise
Small Size
Medium-rise
Rigid
Buildings and Structures
High-rise
Slender
Flexible
Particularly
<strong>Wind</strong> Sensitive
Simplified
Detailed Method
- Crosswind
Method
- Along-wind
- Roof
- Torsion
- Cladding
- Quasi-steady
steady- Size Reduction Effects
- Quasi-static
static - Resonance Effects
- Vortex
Resonance
- Aerodynamic
Instability
- <strong>Wind</strong> Tunnel
Tests, etc.
2

<strong>Design</strong> <strong>Wind</strong> Speed U H (m/s)
U
H
= U
0
K
D
E
H
k
rW
U 0 : Basic wind speed
K D : <strong>Wind</strong> directionality factor
E H : <strong>Wind</strong> speed profile factor
rW : Return period conversion factor
k rW
Basic <strong>Wind</strong> Speed
• Meteorological Standard Condition
- 10min mean
- 10m above ground
- Open flat terrain
- 100-year
year-recurrencerecurrence
• Typhoon <strong>Wind</strong>s : Monte-Carlo
Simulation
• Synoptic <strong>Wind</strong>s : Meteorological Data
Combined probability
3

Basic <strong>Wind</strong> Speed U 0 (m/s)
36
32
34
34 30
32
36
32
30
32
32
38
30
36
34
34
32
40
34
32
30 34
36
32
30
36
36
30
40
32
36
44
36
34
42
34 30
34
44
36
40
38
40
44
36
40 42
44
Okinawa: 50m/s
Lower Limit: 30m/s
Orientation of Building and
<strong>Wind</strong> Direction
• B = 20m, D = 40m, H = 40m
Maximum
Acceleration
63%
100%
Maximum
Displacement
50% 100%
4

<strong>Wind</strong> Directionalityity Factor
• Davenport (1969)
• Holmes (1981)
• Cook (1983)
• Melbourne (1984, 1990)
→ AS 1170.2 (1989)
AS/NZS 1170.2 (2002)
• Simiu & Heckert (1998)
<strong>Wind</strong> Directionalityity Factor
in Major Codes
• ASCE 7-987
- Buildings: 0.85 <strong>for</strong> all directions
Chimneys: 0.9 or 0.95 <strong>for</strong> all directions
Except <strong>for</strong> hurricane-prone regions
• AS/NZS1170.2(2002)
- Tropical-cyclone
cyclone-prone regions:
0.95 or 1.0 <strong>for</strong> all directions
- Non-tropical
tropical-cyclone-prone regions:
<strong>Wind</strong> Direction Multiplier <strong>for</strong> 8 sectors
5

<strong>Wind</strong> Directionalityity Factor
• Difficulty in tropical-cyclone
cyclone-prone
regions
Meteorological records in Japan:
- 75 years of reliable records at most
- Approx. 3 landfalls/year of typhoons
- Very few typhoon data in each sector
divided into 8 or 16 sectors of azimuth
<strong>for</strong> a given site
Large sampling error
<strong>Wind</strong> Distribution in Typhoon
Direction of
Movement
10m/s 20m/s 30m/s
40m/s
50m/s
Northern Hemisphere
Dangerous
Semicircle
6

<strong>Wind</strong> Directionality Factor
in Japan
• Hybrid use of meteorological data
during typhoon passage and Typhoon
Simulation technique
→ Reflecting effects of large-scale
topography and terrain roughness
- Correlations between observed wind
speed and simulated friction free
wind speed
- Correlations between observed wind
direction and simulated friction free
wind direction
p 1
Generation of Virtual
Meteorological Data in Tropical
Cyclone Prone Region
Simulated Friction Free <strong>Wind</strong>
(FFW)
- <strong>Wind</strong> Speed U FF
Correlations
- <strong>Wind</strong> Direction D FF
Typhoon Path
p 3
Meteorological Records
p p - <strong>Wind</strong> Speed U
p 2 i
p ME
4 - <strong>Wind</strong> Direction D ME Pressure Records at
Meteorological Stations
Typhoon Simulation
Virtual
(FFW)
Meteorological Data
5000 years 5000 years
7

Generation of Virtual
Meteorological Data in Tropical
Cyclone Prone Region
Calculation of Correlations
Correlations Between Evaluated FFW (U FF , D FF ) and Observed
<strong>Wind</strong> Records (U(
ME , D ME ) Using All Available Typhoon Records
Typhoon Simulations
(5,000 years)
Monte-Carlo Simulation
at Meteorological Stations
- <strong>Wind</strong> Speed U SFF
- <strong>Wind</strong> Direction D SFF
(FFW)
Virtual Meteorological <strong>Wind</strong>
Data (5,000 years)
Probabilistic Conversion
of
Simulated FFW W (U(
SFF , D SFF )
to
Virtual Meteorological <strong>Wind</strong>
Data (U(
vir , D vir )
Evaluation of Directional
R-year Recurrence <strong>Wind</strong> Speed
in Tropical Cyclone Prone Region
Virtual Long-term
Meteorological Data
Sufficient <strong>Wind</strong> Records
in Each Sector
R-year Recurrence <strong>Wind</strong> Speed
<strong>for</strong> Each <strong>Wind</strong> Direction
8

<strong>Wind</strong> Directionality
(Tokyo, 100-year Recurrence
Hybrid Use of Typhoon Simulation and
Meteorological Records
Equivalent Annual
Exceedence Probability of
Directional <strong>Wind</strong> Speed
• Corresponding to an annual
exceedence probability of load effects
(base shear, base moment, etc.)
corresponding to 100-year recurrence
• Under different conditions:
- load effects
- building shape
- orientation
- geographic location
- design target (structural(
frames,
components and cladding)
9

Equivalent Directional
<strong>Design</strong> <strong>Wind</strong> Speed U D
• Annual probability of exceedence of a
wind load effect = 1/1001
100 (100-year
Recurrence)
1. Calculation of 100-year recurrence
wind load effect (e.g. internal <strong>for</strong>ce,
peak pressure) based on the actual
wind climate at a given site
Q X,100
← Site, Building Shape,
Orientation, Load Effect, etc.
Equivalent Directional
<strong>Design</strong> <strong>Wind</strong> Speed U D
2. Calculation of equivalent return
period causing the same 100-year
recurrence wind load effect in the
most unfavorable case
≈ 150 – 200 years
Q X,100
10

Equivalent Directional
<strong>Design</strong> <strong>Wind</strong> Speed U D
2. Calculation of equivalent return
period causing the same 100-year
recurrence wind load effect in the
most unfavorable case
3. Calculation of average directional
wind speeds U D based on the
equivalent return period <strong>for</strong> various
cases at each meteorological site
Equivalent Directional
<strong>Design</strong> <strong>Wind</strong> Speed U D
Ave. ± σ
(m/s)
11

Equivalent Directional
<strong>Design</strong> <strong>Wind</strong> Speeds
Chiba
<strong>Wind</strong> Directionality Factor K D
(8 azimuths)
Equivalent Directional <strong>Design</strong> <strong>Wind</strong> Speed
K D =
Basic <strong>Wind</strong> Speed U 0
• If you have aerodynamic shape factors
<strong>for</strong> all wind directions, K D can be used
directly.
• If you use aerodynamic shape factors
C f specified in the <strong>AIJ</strong>-RLB, there is a
limitation.
Structural Frames : Specified
method
Cladding/Components : K D = 1
12

<strong>Wind</strong> Speed Profile Factor E
E r
E g
E = E r E g
: Exposure factor <strong>for</strong> flat terrains
: Topography factor <strong>for</strong> mean
wind speed
E
r
Z G
Z b
Exposure Factor
<strong>for</strong> Flat Terrains E r
α
⎧ ⎛ Z ⎞
⎪1.7
< ≤
⎪
⎜
⎟ Z
b
Z Z
=
⎝ Z
G ⎠
⎨
α
⎪ ⎛ Z
b
⎞
⎪
1.7
⎜
⎟ Z ≤ Z
b
⎩ ⎝ Z
G ⎠
: Gradient height
: Interfacial layer height
G
13

Z
700 m
600
500
400
300
200
100
Exposure Factor
<strong>for</strong> Flat Terrains E r
Category V
IV
III
II I
V
III
I
IV
II
0 0 0.5 1 1.5 2
E r
Topography Factor E g
H S
Escarpments
θ S
X S
Ridges
θ S
X S
H S
14

Topography Factor E g
• A series of wind tunnel tests and
numerical simulations
E
g
C
=
1
Topography Factor E g
( C −1)
⎧
× exp⎨−
C
⎩
, C and C
2
1
⎧
⎨C
⎩
3
2
⎛
⎜
⎝
Z
H
S
2
− C
⎛
⎜
⎝
3
Z
H
S
⎞ ⎫
⎟ + 1⎬
⎠ ⎭
− C
⎞⎫
⎟⎬
+ 1
⎠⎭
: Constants depending
on slope angle and
distance from upper
edge
3
≥ 1
15

Topography Factor E g
0 Eg 1
Proposed Formula
E g
-3 -2 -1 0 1 2 3 4 5 6
X
H
S
S
1 1
Return Period Conversion
Factor k rW
k
rW
0 .62( λ −1)ln
r − 2.9λ
+ 3.9
=
U
U
λ U
= U 500
U 0
U 500
U 0
: 500-year
year-recurrence recurrence wind speed
<strong>for</strong> the meteorological standard
conditions
: Basic wind speed
(100-year
year-recurrence)
recurrence)
16

500-year
year-recurrence recurrence <strong>Wind</strong>
Speed U 500 (m/s)
38 36
36
40
34
36
36
38
42
34
40
42
38
38
36
38
46
44
36
34
34 38
36
36
40
34
40
42 40
34
34
36
36
44
40
48
40
44
36
48
36
34
44
48
40
38
42
40
42
44 48 40
44 46
48
36
38
36 34
36
Okinawa: 58m/s
Lower Limit: 34m/s
Turbulence Intensity I Z
at Height Z
I =
Z
I
rZ
E
gI
I rZ
E
gI
=
E
E
I
g
: Turbulence Intensity <strong>for</strong>
flat terrains
Topography factor <strong>for</strong>
fluctuation wind speed σ u
: Topography factor <strong>for</strong>
turbulence intensity
Topography factor <strong>for</strong>
mean wind speed U
17

Turbulence Intensity <strong>for</strong> Flat
Terrains I rZ at Height Z
⎧ ⎛ Z
⎪0.1
⎪
⎜
⎝ Z
⎨
⎪ ⎛ Z
⎪
0.1
⎜
⎩ ⎝ Z
⎞
⎟
⎠
⎞
⎟
⎠
−α
−0.05
G
I
rZ
=
−α
−0.
05
b
G
Z
b
< Z ≤ Z
Z ≤ Z
b
G
Turbulence Scale L Z (m)
at Height Z
L
Z
=
⎧
⎪
⎛
100⎜
⎨ ⎝
⎪
⎩
Z
30
100
⎞
⎟
⎠
0.5
30m
Z
<
≤
Z ≤ Z
30m
G
<strong>for</strong> every terrain category
18

<strong>Wind</strong> <strong>Loads</strong> Specified
in <strong>AIJ</strong>-RLB
• For Main Frames
- Horizontal Along-wind Load
Ccrosswind Load
Torsional Load
- Roof <strong>Wind</strong> Load
• For Cladding / Components
- Peak Cladding Load
Along-wind <strong>Loads</strong> on
Ordinary Buildings W D (N)
at Height Z
W
q H
D =
q
H
C
G
A
: Velocity pressure at reference
height H
C D
: Aerodynamic shape factor
G D
: Gust loading factor
A : Projected area
• GLF based on Base Bending Moment
(Zhou & Kareem, 2001)
D
D
19

C ′
φ D
R D
GLF <strong>for</strong> Along-wind <strong>Loads</strong>
on Ordinary Buildings
'
g
2
GD = 1+ gD 1+φD RD
Cg
g D
and
g
C g
C
: Peak factor
: Fluctuating and mean
coefficients <strong>for</strong> along-
wind OTM
: Correction factor depending
on mode shape
: Resonance factor
<strong>Wind</strong> <strong>Loads</strong> on Roof
Structures W R (N)
W = q
q H
C
R
G R
A R
R
H
C
R
G
: Velocity pressure at reference
height H
C :
pe
− C
pi
Aerodynamic shape factor
: Gust loading factor
: Subjected area <strong>for</strong> roof beam
=
R
A
R
20

GLF <strong>for</strong> <strong>Wind</strong> <strong>Loads</strong>
on Roof Structures
G
C
R
= 1±
G
R
12.3r
2
Re
( 1+
R )
1−
r
Re
c
+ 0.3r
2
c
( 1+
R ) 0. 3
2
= ± 0.25 12.3r
Re
Re
+
C pi
−0.4,
C ≠ 0
=
R
C pi
−0 .4, C = 0
=
R
R
( )
2
G +
r
2
R
= 1±
12.3rRe 1+
RRe
0. 3rc
R
Re,
Re
, and
r c
C pi
= 0
: Parameters depending on roof
beam direction, dynamic
characteristics of roof structure,
and wind characteristics
Along-wind <strong>Loads</strong> on
Lattice Towers W D (N)
at Height Z
W = q
q Z
C D
G D
A
D
Z
C
D
G
D
A
F
: Velocity pressure at height Z
: Aerodynamic shape factor
: Gust loading factor
: Projected area
21

g D
C ′
φ D
R D
GLF <strong>for</strong> Along-wind <strong>Loads</strong>
on Lattice Towers
C′
G = 1+
φ 1+
D
and
g
C g
g
g D D RD
Cg
: Peak factor
: Fluctuating and mean
coefficients <strong>for</strong> along-
wind OTM
: Correction factor depending
on mode shape
: Resonance factor
Crosswind <strong>Loads</strong> and
Torsional <strong>Loads</strong>
Slender and flexible buildings
to satisfy following condition:
H
BD
≥ 3
U H
D
H
B
22

W
Crosswind <strong>Loads</strong> on
Buildings W L (N) at Height Z
g L
L
Z
2
= 3q
H
C′
L
A g
L
1 + φL
R
H
3
2
( D B) − 0.071( D B) + 0. ( D B)
C L
′ = 0.0082
22
φ L
R L
: Peak factor
: Correction factor <strong>for</strong> mode shape
: Resonance factor
L
Torsional <strong>Wind</strong> <strong>Loads</strong> on
Buildings W T (Nm) at Height Z
W = 1.8q C′
AB Z g 1+
φ R
H
2
T H T T T T
C T
′ = 0.0066 +
g T
φ T
R T
{ 0.015( D / B)
2 } 0.78
: Peak factor
: Correction factor <strong>for</strong> mode shape
: Resonance factor
23

Correction Factors
Depending on Mode Shape φ
• Ordinary buildings
1−
0.4ln β M
φD
=
2 + β M
2
( )
2
M B + D
φT
=
36I
T
M ⎛ Z ⎞
φL
= ⎜ ⎟
3M
⎝ H ⎠
L
β −1
• Lattice Towers
φ
D
=
M
M
D
⎛
⎜
⎝
⎧⎛
B
⎨
⎜0.5
⎩⎝
B
5
D
0
Z
H
⎞
⎟
⎠
β −1
( 1−
0.4ln β )
H
Along-wind loads
(1 − 0.4 ln β )
Crosswind loads
Torsional wind loads
⎞ ⎫
− 0.3
⎟(
β − 2) + 1.4⎬( 1−
0.4ln
β )
⎠ ⎭Along-wind loads
β
⎛ Z ⎞
µ = ⎜ ⎟
⎝ H ⎠
Mode shape
Vortex Resonance and
Aerodynamic Instabilities
• Particularly wind-sensitive
buildings to satisfy following
conditions:
H
Non
≥ 4
BD
and
f
,
⎛
⎜
⎝
L
f T
U H
Non-dimensional
onset velocity
H
D
B
U
⎞
H
* U
H
*
≥ 0.83U
⎟
Lcr
or ≥ 0.83U
Tcr
f
L
BD
fT
BD ⎠
: Fundamental natural
frequencies of crosswind
vibration and torsional vibration
24

Non-dimensional
Onset Velocity (Crosswind)
Terrain
Category
I & II
III, IV
& V
Side Ratio
D/B
D/B≤ 0.8
0.8 0.7
All
δ L ≤ 0.2
0.2 0.8
δ L ≤ 0.4
δ L > 0.4
All
Onset Velocity
U* Lcr
16δ L
11
1.2δ L +7.3
2.3
12
15 δ L
3.7
Not occur
4.5δ L +6.7
0.7δ L +8.8
11
D
B
Non-dimensional
Onset Velocity (Torsional)
Side Ratio
D/B
D/B≤1.5
1.5

Vortex Resonance of
Circular Cylinders
• Buildings with a circular plan
to satisfy following conditions:
H
D
m
U
H
≥ 7 and ≥
f D
L
m
4.2
U H
D m
H
f L
: Fundamental natural frequency
of crosswind vibration
W
<strong>Wind</strong> <strong>Loads</strong> on Circular
Cylinders W r (N) <strong>for</strong> Vortex
Resonance at Height Z
U = 5 f
r
C r
r
f L
= 0.8ρU
D
2
r
C
r
Z
H
A
U H
: Resonance wind speed
L m
(m/s)
: Equivalent aerodynamic shape
factor <strong>for</strong> vortex resonance
- tabulated in <strong>AIJ</strong>-RLB
: Fundamental natural frequency
of crosswind vibration
Z
D m
H
26

Phase-plane Expressions of
Column Tip Displacements
and Base Bending Moments
Displacement
Bending Moment
Peak Normal Stresses in
Column C1
Load Conditions
ALL :
F D F L F T M D M L M T
Along-wind
F D only
Crosswind
F L only
Torsional Moment M T
only
ALL
Along-wind F D only
(Low-rise Sq. Model, α =1/4)
Tensile Compressive
Stress kN/cm 2 Stress kN/cm 2
Peak Value (P.F.) Peak Value (P.F.)
5.4 (4.56)
4.2 (4.42)
1.7 (3.95)
0.9 (4.36)
130%
• Ensemble averaged values of 12 samples
• The worst case was a 75% increase in tensile stress.
− 4.7 (− 4.50)
− 4.1 (− 4.42)
− 1.8 (− 3.95)
− 0.9 (− 4.36)
115%
27

Combinations of <strong>Wind</strong>
Load
Components
• Low- and medium-rise buildings
- Y. Tamura, H. Kikuchi and K. Hibi (2002)
- H. Kikuchi, Y. Tamura and K. Hibi (2002)
Peak normal stresses in columns
• High-rise buildings
- Asami (2000, 2002)
Combination methods considering
correlations of along-wind, crosswind
and torsional responses
<strong>Wind</strong> Load Combination <strong>for</strong>
Low- and Medium-rise
Buildings
W D
W LC = γ W D
Combination Factor
28

Combination Factor γ <strong>for</strong> Low-
and Medium-rise Buildings
Combination Factor γ
=
Column Normal Stress by All <strong>Wind</strong> Force Components
Column Normal Stress by Along-wind Force only
− 1
Combination Factor γ <strong>for</strong> Low-
and Medium-rise Buildings
(Kikuchi, Tamura & Hibi, , 2002)
Combination Factor γ
Building Height
Only Quasi-static
static
Component
With Resonant
Component
29

Combination Factor γ
Combination Factor γ <strong>for</strong> Low-
and Medium-rise Buildings
Combination Factor γ
1.5
1
0.5
0
0 1 2 3
Side Ratio D/B
(Kikuchi, Tamura & Hibi, , 2002)
B
W L = γ W D
D
W D
(H = 40m)
Combination Factor γ <strong>for</strong> Low-
and Medium-rise Buildings
Combination Factor γ
1.5
1
0.5
B
W L = γ W D
D
W D
γ = 0.35 (D/B(
D/B)
0
0 1 2 3
Side Ratio D/B
(Kikuchi, Tamura & Hibi, , 2002)
With Resonant
Component
Quasi-static
static
Component only
(H = 80m)
30

<strong>Wind</strong> Load Combinations s <strong>for</strong>
High-rise Buildings
m
my,max
1
2 + 2ρ
−1
ρ
0 ( M x
, M
y
) 1
1−
2 − 2ρ
y
<strong>Design</strong>
Points
<strong>for</strong> M x,max
= M +
m
m
x
x,max
x
m x,max
<strong>Wind</strong> Load Combinations s <strong>for</strong>
High-rise Buildings
Combination
Along-wind
Load
Crosswind
Load
Torsional Load
1
2
3
W D
⎛ 0.6 ⎞
⎜0.4
+
⎟
⎝ G D ⎠
⎛ 0.6 ⎞
⎜0.4
+
⎟
⎝ G D ⎠
W D
W D
0.4
W L
W L
( 2 2ρ
−1)
+ LT
W L
0.4
( )
W T
2+ 2ρ
LT
−1
W T
W T
31

Correlation Coefficient ρ LT
between Crosswind Response
and Torsional Response
- tabulated in <strong>AIJ</strong>-RLB
- depends upon D/B
f θ / f L
f 1 B/U H
The smaller of f θ and f L
Combinations of Horizontal
<strong>Wind</strong> LoadL
and Roof wind
Load
• It t is recommended to simply
superimpose the horizontal wind load
and roof wind load.
- Y. Tamura, H. Kikuchi and K. Hibi (2003)
The vertical component of the wind
<strong>for</strong>ce acting on medium-rise buildings
tended to become largest when one of
the horizontal wind <strong>for</strong>ce components
reached its maximum value .
32

<strong>Wind</strong> <strong>Loads</strong> <strong>for</strong> Components
and Cladding
W R (N)
Cˆ
W
C
Ĉ pe
*
C
pi
A
C
= Cˆ
pe
=
− C
q
*
pi
H
Cˆ
C
A
C
: Peak external pressure coefficient
: Coefficient accounting <strong>for</strong> the
effect of the internal pressure
fluctuation
: Tributary area
Equivalent internal
pressure coefficient
Aerodynamic Shape Factors
• External wind pressure coefficients
<strong>for</strong> structural frames:
- Buildings with rectangular sections (H>45m)(
- Buildings with rectangular sections with flat,
shed, or gable roofs (H≤45m)
- Circular arc roofs (H≤45m)(
- Dome roofs
Internal wind pressure coefficients C pi
• Internal wind pressure coefficients
<strong>for</strong> structural frames
- Buildings without dominant openings
C pe
33

Aerodynamic Shape Factors
• External wind <strong>for</strong>ce coefficients
<strong>for</strong> structural frames:
, C
D X
- Buildings with circular sections
- Pitched free roofs with a rectangular plan
- Lattice structures
- Fences
- Members with various sections
- Nettings
C
, C
Y
Aerodynamic Shape Factors
• External peak pressure coefficients
<strong>for</strong> cladding and components:
- Buildings with rectangular sections (H>45m)(
- Buildings with rectangular sections with flat,
shed, or gable roofs (H≤45m)
- Buildings with circular sections
- Circular arc roofs (H≤45m)(
- Dome roofs
• Coefficients accounting <strong>for</strong> the effect of
the internal pressure fluctuation <strong>for</strong>
*
C
cladding and components
pi
- Buildings without dominant openings
Ĉ pe
34

Aerodynamic Shape Factors
• External peak wind <strong>for</strong>ce coefficients
<strong>for</strong> cladding and components:
Ĉ
- Pitched free roofs with a rectangular plan C
1-year-recurrence recurrence <strong>Wind</strong>
Speed U 1 (m/s)
• <strong>AIJ</strong> Guidelines <strong>for</strong> the Evaluation of
Habitability to Building Vibration (1991)
(Its revised version will be published in 2004)
- 1-year-recurrence recurrence peak acceleration has
been applied <strong>for</strong> the evaluation
35

1-year-recurrence recurrence <strong>Wind</strong>
Speed U 1 (m/s)
20
• 10min mean
• Flat open category
• 10m above the ground
20
20
20
15
15
20
20
15
20
20
20
Miscellaneous
• Evaluation <strong>for</strong>mulae <strong>for</strong> along-wind,
crosswind and torsional acceleration
responses
• Interference effects of neighboring
buildings
• Uncertainty and dispersion of
parameters included in <strong>AIJ</strong>-RLB
RLB-2004
- to achieve reliability based design
36