1st Peru-Japan Workshop on
Enhancement of Earthquake andTsunami Disaster Mitigation
TechnologyThe Role of Innovation ing the RegionalgReducing
Seismic Risk in
Latin-AmericaAmador Terán Gilmore

BackgroundThe many urgent problems faced by LatinAmerican countries drain their energy awayfrom the formulation and development ofinnovative and efficient structural solutions forearthquake-resistance.

Innovation on
Seismic Resistance:
Damage Control

The level of damage suffered by the structural andnon-structural elements, as well as the contents ofearthquake-resistant buildings depends on theirdisplacement, velocity and acceleration demands.
A lower level of response implies a lower level ofdamage.

Structural and non-structural damage control requires
displacement-control

Contents damage control requires velocity andacceleration-control

MexicoUnited States

Taiwan

Chile

100%

20.0%

17.0%
44.0%

80%

C t t
Contents60%
62.0%

Nonstructural

70.0%

40%

Structural
48.0%

20%
18.0%

13.0%

8.0%

OfficeHotel

Hospital0%

After Miranda and Taghavi
Tagha i

The economic losses due to damage to contents
can be significant.

Innovation in terms of earthquake resistanceimplies 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 thedesign seismic input (ground motion).

World-wide
Tendencies

Do more with less…

Recently,
American experts
estimated thatbraced frames
concentrate 40%of the comercial
steel market in
California. Thissystem accounted
for less than 10%of the market adecade ago (Urisand Mahin).

Since 1999,
approximately
70% of thebuildings built inJapan with heights
larger than 60
meters have been
designedaccording to theconcept of damage
tolerant structure(Wada, Huang andBertero).

Hearst Tower(diagrid)

20% Less weight
90% Recycled material

Whatt aboutWhb t
Latin-America?

Do more with less…

Within a context of sustainable development, LatinAmericans need to be capable of designing andbuilding earthquake-resistant structural systems
that are or have:
1.Lighter
2.Safer
3.Larger life span

A promising approach to accomplish this is that ofg tolerant structure.
damage
The concept of damage tolerance implies thatstructural damage due to earthquake, which has tobe controlled within acceptable thresholds,
concentrates in specific structural elements, known
as sacrificial elements. Their function is toconstitute themselves in structural fuses that
protect the primary or gravitational system.

Vista en Planta
Material
desadherente

Núcleo(fluye)Núcleo deaceroVista lateral
Tubo de acero
Tubo deacero

Material
confinanteCorte A-AA

A

Vb

Total SystemδazPrimary
SystemFuses

Primary System≈δaz

BracesVbδaz

SEGURIDADSERVICIO
Gravitacional: Operación Inmediata
Contraventeo: Operación Inmediata
No Estructural: Operación InmediataGravitacional: Operación Inmediata
No Estructural: Seguridad de Vida

Gravitacional: Elástico
Contraventeo: Cercano a elásticoOI
No estructural: IDI SER ≤ IDI NE

OI
Gravitacional: IDI SEG ≤ IDI SG.

IDI SSER = f (IDI SER )IDI SSEG = f (IDI SEG )δ SSERδ SSEGδ BSERδSV
No estructural: IDI. SEG ≤ IDI. NE

Concepción y diseñode sistema gravitacional
Análisis estático no lineal
de sistema gravitacional
OI
Establecer IDI SG, TSG

IDI Sy ≈ IDI SSER
SEG

δTSEG

S dSERS dSEG

SdS

ξ=2%μ=1

SdSdSEGTTTSERμ Sent = IDI S

SEGBδ TSER

SERd

μS = f (μ )μmax =

δ SSEG + δ BSEG
δ SSEG μS + δ BSEG

ξ=5 %μ= μmax

TTSEG

T

TCV = f (TT , TSG )TS

TB

Dimensionado decontravientos

Dimensionado decolumnas de soporterRevisión decolumnas desoporte

IDI Syent
S

TT = f (TTSER , TTSEG )Ajuste necesario

Vb

Adecuadas

FIN

Traditional Structural Skeleton:
Beams 3,900 tons
Columns 8,100 tons
Braces 500 tons
T t l 12,500Total
12 500 tonstInnovative Structural Skeleton:
Beams 1,200 tons
Columns 3,000 tons
Braces 600 tons
Total 4,800 ton

Confidence Levels

Building

Service

Life Safety

Collapseprevention

Innovative
Traditional

42 %
7%

92 %
53 %

99 %
94 %

Do more with less…

Innovation can be applied toour traditional structuralsystems!

VIGA DEACOPLAMIENTOENTE
SECCIONES INFINITAM
RIGIDAS.

60

Resultados experimentales (+)

CO
L
U
M
N
A
A
N
C
H
A

CO
L
U
M
NA
A
NCH
A

COL
U
M
NA
A
NCH
A

ARTICULACIONES CON LASPROPIEDADES A CORTE DEL
MUROCOLUMNAANCHA

Cortante Basal (Ton)4530

Resultados analiticos
15-0.6%-0.5%-0.4% -0.3% -0.2%-0.1%

00.0%-15-30Resultados experimentales (-)-45-60DI(%)

Specimen 3D (Alcocer 1993)

0.1%

0.2%

0.3%

0.4%

0.5%

0.6%

What about contents?
Acceleration-based Design!

Sa/g

1600
1400
1200

2A [cm/s ]

1000
800
600
400
200
0012

3

T [seg]

456T (sec)One way to avoid unacceptable damage in contents isto limit the maximum acceleration demands in thesuper-structure.
Consider the ratio of the maximum acceleration in thesuper-structure to that at the base:amaxܽ݉ܽ‫ݔ‬ܴൌܾܽ݉ܽ‫ݔ‬
abmax

2.2

1.8

1.6

4-story base-isolated building

1.4

12
1.2

1.0

0.8
024

68

1012Tb/Ts

1416182022

Tb / Ts2.0

γ = 0.67

R
1.8

R4N,γ=0.67,ζ=10%=Az/Ab

R4N,γ=0.8,ζ=10%=Az/Ab

γ = 0.80

R

2.0

1.6

1.4

1.2

1.0

0.8
024

681012Tb/Ts

14161820

22

Tb / Ts1.35R1.30

ξ = 10%ξ = 15%
ξ = 20%ξ = 25%

1.20
1.15
1.10
1.05
1.00
0.95
0246810121416

182022

Tb / Ts

Tb/Ts

1.6
ξ = 10%ξ = 15%
ξ = 20%ξ = 25%R

1.54-story base-isolated building

R4N,γ=0.67=Az//Ab

1.4

1.3

1.2

1.1

1.0

0.9
02

4

68

10121416

Tb/Ts

Acceleration control in contents¿amaxco?
Floor Motion
Sa/g

1600

A [cm/s2]

R4N,γ=0.80 Az/Ab

1.25001400

01200

01000

00800

0600
0400
0200
00

123

456T (seg)T [seg]800600400

2000-200-400-600

05101520253035

Ground motion

4045

182022

Tb / TsRigid super-structure

Flexible super-structureamaxco1400

amaxco1600
ξb=10%
ξb=20%

2

A [cm/seg ]2A [cm/seg ]ξb=15%
ξb=20%

1200

ξb=25%

1000

ξb=10%

1400

ξb=15%

1200

800

600

amax

400

amax

200

ξb=25%

1000
800
600
400
200

000

1

2

3

T [seg]

4

560Tco (sec)1

23

T [seg]Tb=2.0 sec

Reflection

456Tco (sec)Latin-Americans need to re-interpret what they
past with the ppurposepofhave learned in the pchanging their future.
It is important to develop new and local solutions tosolve the huge needs of our region. We need todevelop our technological potential throughdeveloping innovative design methodologies andstructural systems that yield safe and efficient
structural systems.