1st Peru-Japan Workshop on Enhancement of Earthquake and
Tsunami Disaster Mitigation Technology
The Role of Innovation in Reducing the Regional
Amador Terán Gilmore
g gSeismic Risk in Latin-America
Background
The many urgent problems faced by Latin-American countries drain their energy away from the formulation and development of innovative and efficient structural solutions for earthquake-resistance.
Innovation onInnovation on Seismic Resistance:
Damage ControlDamage Control
The level of damage suffered by the structural andThe level of damage suffered by the structural and non-structural elements, as well as the contents of earthquake-resistant buildings depends on their displacement, velocity and acceleration demands.
A lower level of response implies a lower level of damage.damage.
Structural and non-structural damage control requires displacement-control
Contents damage control requires velocity and acceleration-control
Mexico
United States
Taiwan
Chile
20.0% 17.0%
44.0%80%
100%
C t t
18.0%
62.0%
13.0%
70.0%
8.0%
48.0%
0%
20%
40%
60%
Office Hotel Hospital
Contents
Nonstructural
Structural
After Miranda and Tagha i
The economic losses due to damage to contentscan be significant.
After Miranda and Taghavi
Innovation in terms of earthquake resistance implies that the structural properties of a building need to be designed in order to control, within acceptable economical and technical constraints, the dynamic response of that building during the design seismic input (ground motion).
World-wideTendencies
Do more with less…
Recently, American experts estimated that braced frames concentrate 40% of the comercial steel market in California. This system accounted for less than 10%for less than 10% of the market a decade ago (Uris and Mahin).
Since 1999, approximately 70% of the buildings built in Japan with heights larger than 60 meters have been designed according to the concept of damageconcept of damage tolerant structure (Wada, Huang and Bertero).
Hearst Tower(diagrid)
20% Less weight
90% Recycled material
Wh t b tWhat about Latin-America?
Do more with less…
Within a context of sustainable development, Latin-Americans need to be capable of designing andAmericans need to be capable of designing and building earthquake-resistant structural systems that are or have:
1.Lighter2.Safer3.Larger life span3.Larger life span
A promising approach to accomplish this is that of damage tolerant structure. g
The concept of damage tolerance implies that structural damage due to earthquake, which has to be controlled within acceptable thresholds, concentrates in specific structural elements, known as sacrificial elements. Their function is to constitute themselves in structural fuses that protect the primary or gravitational system.
Vista en Planta
Núcleo(fluye)
Vista lateral
Tubo de acero
A
A
Corte A-A
Tubo deacero
Materialdesadherente
Núcleo deacero
Materialconfinante
Vista en Planta
Núcleo(fluye)
Vista lateral
Tubo de acero
A
A
Corte A-A
Tubo deacero
Materialdesadherente
Núcleo deacero
Materialconfinante
Primary System Fuses
≈PrimarySystem
Vb
δaz
Total System
Vb
δaz
≈Braces
Vb
δaz
Gravitacional: Operación InmediataContraventeo: Operación Inmediata
No Estructural: Operación Inmediata
Gravitacional: .
No estructural: . .
Gravitacional: Operación InmediataNo Estructural: Seguridad de Vida
Concepción y diseñode sistema gravitacional
Análisis estático no linealde sistema gravitacional
Establecer
SERVICIO SEGURIDAD
Gravitacional: ElásticoContraventeo: Cercano a elásticoNo estructural:
OISG
SEG IDIIDI ≤SVNE
SEG IDIIDI ≤ SGOISG TIDI ,
SEGSent
SERS
yS
IDI
IDIIDI ≈SERSδ
OINE
SER IDIIDI ≤
SEGSδ
( )SERSERS IDIfIDI = ( )SEGSEG
S IDIfIDI =
)( entSS
yS
SentS
f
IDIIDI
μμ
μ
=
=
SERTδ
SERdS
SEGBS
SEGS
SEGB
SEGS
max δμδδδμ+
+=
SEGTδ
SEGdS
SERBδ SEG
Bδ
T
Sd
μ=1ξ=2%
SERdS
SERTT
T
Sd ξ=5 %μ= μmax
SEGdS
SEGTT
)( SEGSER TTfT
Dimensionado de contravientos
ST BT
Dimensionado de columnas de soporte
rRevisión de columnas de
soporteFIN
Ajuste necesario
),( SEGT
SERTT TTfT =
),( SGTCV TTfT =
Adecuadas
Traditional Structural Skeleton:
Beams 3,900 tonsColumns 8,100 tons
Braces 500 tons
T t l 12 500 t
Innovative Structural Skeleton:
Total 12,500 tons
Beams 1,200 tonsColumns 3,000 tonsBraces 600 tons
Total 4,800 ton
Confidence Levels
Building Service Life Safety Collapse
prevention
InnovativeTraditional
42 %7 %
92 %53 %
99 %94 %
Do more with less…
Innovation can be applied to our traditional structural
systems!
VIGA DEACOPLAMIENTO
SECCIONES INFINITAMENTE
RIGIDAS.
45
60Resultados experimentales (+)
COLUMNA ANCHA
COLUMNA ANCHA
COLUMNA ANCHA
COLUMNA ANCHA
ARTICULACIONES CON LASPROPIEDADES A CORTE DEL
MURO -60
-45
-30
-15
0
15
30
-0.6% -0.5% -0.4% -0.3% -0.2% -0.1% 0.0% 0.1% 0.2% 0.3% 0.4% 0.5% 0.6%
DI(%)
Co
rtan
te B
asal
(T
on
)
Resultados analiticos
Resultados experimentales (-)
Specimen 3D (Alcocer 1993)
What about contents? Acceleration-based Design!
1200
1400
1600Sa/g
A [
cm/s
2 ]
400
600
800
1000
T [seg]
0 1 2 3 4 5 6
0
200
T (sec)
One way to avoid unacceptable damage in contents is to limit the maximum acceleration demands in the super-structure.
Consider the ratio of the maximum acceleration in the super-structure to that at the base:
amax
abmax
R4N
,γ=
0.8
,ζ=
10%
=A
z/A
b
1 2
1.4
1.6
1.8
2.0
2.2
4-story base-isolated building
γ = 0.80R
Tb/Ts
0 2 4 6 8 10 12 14 16 18 20 22
0.8
1.0
1.2
Az/
Ab
1.6
1.8
2.0
γ = 0.67Tb / Ts
R
Tb/Ts
0 2 4 6 8 10 12 14 16 18 20 22
R4N
, γ=
0.6
7,ζ =
10%
=
0.8
1.0
1.2
1.4
Tb / Ts
R4N
,γ=
0.8
0A
z/A
b
1.10
1.15
1.20
1.25
1.30
1.35
ξ = 10% ξ = 15% ξ = 20% ξ = 25%
R
Tb/Ts
0 2 4 6 8 10 12 14 16 18 20 22
0.95
1.00
1.05
/Ab
1.4
1.5
1.6
ξ = 10% ξ = 15% ξ = 20% ξ = 25%
Tb / TsR
Tb/Ts
0 2 4 6 8 10 12 14 16 18 20 22
R4N
,γ=
0.6
7=A
z/
0.9
1.0
1.1
1.2
1.3
Tb / Ts
4-story base-isolated building
Floor Motion
Acceleration control in contents¿amaxco?
400
600
800
0
0
0
0
0
0
0
0
0
Floor Motion
T [seg]
0 1 2 3 4 5 6
A [c
m/s
2 ]
0
200
400
600
800
1000
1200
1400
1600
Sa/g
T (seg)
0 5 10 15 20 25 30 35 40 45-600
-400
-200
0
200
Ground motion
1400 1600
Rigid super-structure Flexible super-structure
amaxco amaxco
A [
cm/s
eg2]
0
200
400
600
800
1000
1200
ξb=10%
ξb=15%
ξb=20%
ξb=25%
A [
cm/s
eg2]
0
200
400
600
800
1000
1200
1400ξb=10%
ξb=15%
ξb=20%
ξb=25%
amax amax
T [seg]
0 1 2 3 4 5 6
T [seg]
0 1 2 3 4 5 6
Tb=2.0 sec
Tco (sec) Tco (sec)
Reflection
Latin-Americans need to re-interpret what they have learned in the past with the purpose of p p pchanging their future.
It is important to develop new and local solutions to solve the huge needs of our region. We need to develop our technological potential through developing innovative design methodologies and structural systems that yield safe and efficient structural systems.
