AISLAMIENTO DE FUNDACIONES

8/2/2019 AISLAMIENTO DE FUNDACIONES

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AISLAMIENTO DE FUNDACIONES

ESTRUCTURAS 5

Para construir edificios resistentes a terremotos, losingenieros deben conocer como se mueve el terrenodurante un terremoto. En las ltimas dcadas la geofisicaha desarrollado instrumentos con capacidad de registrar

las aceleraciones y velocidades del terreno durantegrandes terremotos.

Ahora, los ingenieros tambin disponen de mtodosefectivos para aislar el movimiento del edificio delmovimiento del terreno. Ello se logra instalando en lasfundaciones apoyos flexibles llamados aisladores de labase, estos estan compuestos por capas de lminas deacero intercaladas con capas de caucho o neoprene. Labase tambin puede aislarse mediante una superficiedeslizante. Cuando el terreno se mueve hacia adelante y

hacia atras el edificio permanece quieto.

Los primeros edificios de este tipo construido en EEUUfueron el Law and Justice Center en Rancho Cucamonga( 1985 ), el edificio del departamento de bomberos de laCiudad de Los Angeles ( 1990 ), y el University ofSouthern California Teaching Hospital ( 1991 ), esteltimo tuvo una severa prueba en 1994, cuando elterremoto de Northridge. An cuando el edificio estaba a

unos 30 km del epicentro, la aceleracin horizontalregistrada fue tres o cuatro veces menor de la aceleracinefectiva en el terreno. El edificio fue aisladocorrectamente del movimiento del terreno, movimientosque causaron daos considerables a los edificios vecinos.

En esta simulacin de un

terremoto, el edificio de la

derecha tiene una fundacin

convencional; el edificio de la

izquierda tiene instaladosaisladores de bases en su

fundacin.

Cuando el suelo se mueve

hacia delante y hacia atrs, los

aisladores de base atenuan y

absorben el movimiento,

significativamente disminuye

el movimiento del edificio.

Para repetir la demostracin,pulse en su pantalla.
http://www.um.edu.ar/um/fau/estructura5-anterior/ESTRUCTURAS%201.htmhttp://www.um.edu.ar/um/fau/estructura5-anterior/ESTRUCTURAS%201.htmhttp://www.um.edu.ar/um/fau/estructura5-anterior/ESTRUCTURAS%201.htm


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Luego del terremoto de Loma Prieta en San Francisco, eledificio San Francisco City Hall fue reformado colocandoaisaldores de base en el mismo, y lo mismo se haplanificado o se encuentra en ejecucin. Para fines delao 1998 habia en EEUU 45 edificios en diferentes

etapas de su remodelacin colocando aislaciones debase.

DISIPADORES MECANICOS DE ESTRUCTURAS

Y

AISLACION DE BASES

El diseo sismo resistente tradicional de edificios reduce las fuerzasdinmicas inducidas por sismos severos por medio de la capacidad dedisipacin de energa disponible en vigas, columnas y sus conexiones.

La disipacin de energa se suele concentrar en los extremos de loscomponentes estructurales debido, entre otros motivos, a la facilidad deproporcionar detalles que incrementen su ductilidad. Un diseosismoresistente satisfactorio debe asegurar que para un determinadonivel de demanda de ductilidad global la ductilidad seccional y dematerial disponible no sea superada, en especial teniendo en cuenta lasincertidumbres inherentes en la definicin de la accin dinmica. En losltimos quince aos se ha producido un esfuerzo de investigacin


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importante para encontrar sistemas estructurales dctiles -tales comolos muros de corte acoplados o los prticos excntricos-, en los cualessea posible localizar la disipacin de energa. Ms recientemente, y conel fin de mejorar estos eficientes sistemas estructurales, se hanpropuesto tcnicas avanzadas de diseo sismoresistente que incluyen

los aisladores dinmicos y los disipadores mecnicos de energa.

Estossistemas estructurales permiten localizar las demandas de ductilidadreduciendo la accin dinmica en la estructura significativa mentecomparado con la accin que sera inducida a una estructura tradicional.

El aislamiento de base se puede dividir conceptualmente en doscategoras: aisladores dinmicos con neoprenes reforzados y aisladoresdinmicos de friccin (Kelly 1993). Los aisladores dinmicos conneoprenes reforzados reducen las fuerzs ssmicas incrementando elperodo estructural a valores cercanos a 2-3 segundos. A diferencia deellos, los aisladores dinmicos de friccin reducen la accin ssmica

disipando energa en la junta deslizante del edificio y la cimentacin(Bozzo et al. 1989) Los aisladores dinmicos con neoprenes reforzadoshan sido ampliamente investigados y probados en laboratorios y por elloactualmente son los sistemas ms comnmente empleados en laconstruccin. Sin embargo estos aisladores tienen algunas limitaciones,tales como el ser sensibles al contenido de frecuencias de un terremotoy su vulnerabilidad a la presencia de pulsos largos que ocurren enregistros cercanos al epicentro de un sismo. En contraste con losaisladores de neoprenes, los aisladores de friccin son poco sensitivosal contenido de frecuencias de un sismo y son tambin mseconmicos. Sin embargo, en este segundo tipo de aisladores, lasamplificaciones no lineales en el rango de perodos cortos tambinpueden incrementar significativamente los desplazamiento y enparticular debido a la presencia de pulsos largos y la proximidad de unafalla.

Ambos sistemas de aislamiento de base tienen claras ventajas frente aldiseo evidente considerando el gran nmero de edificios yaconstruidos en el mundo que emplean estos sistemas. Para la prcticaconstructiva en Mendoza tienen limitaciones, por lo que su empleo esrecomendable en nuestro medio slo para edificios muy importantespara los cuales se desee proteger no slo la seguridad de las personasque los ocupen sino adems las instalaciones y equipos disponibles ensu interior.

LISTA DE EDIFICIOS DONDE SE HAN USADO LAS AISLACIONES DE BASE

DISPOSITIVOS DE LA EMPRESA TAYLOR DEVICES, INC.AMORTIGUADORES CON FLUIDOS VISCOSOS


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Nombre y

Tipo deEstructura

Ciudad/Pais

Tipo y numerode

Amortiguadore

s

Fecha de

instalacin

CargaInformacin

Adicional

SanFrancisco-

Oakland Bay

Bridge, WestSpan-

Suspension

Bridge

USA/SanFrancisco, CA

Taylor FluidDampers

Total: 100

2000 kN,483mm

stroke

2450 kN,

584mmstroke

3115 kN,

178mmstroke

Instalacin en

2001

Seismic Retrofit ofsuspension span

between San

Francisco and YerbaBuena island.

Dampers used to

dissipate seismic

energy.

HearstMemorial

Mining

Building

USA/Berkeley,CA

Taylor FluidDampers

Total: 26

890 kN,813mm

stroke

Instalacin en

2000

Seismic Seismic retrofit of a4-story brick

laboratory building

on the U.C.Berkeley campus.

Dampers provide

energy dissipation

for a seismicisolation system.

Sacramento

River Bridge

at Rio Vista

USA/Rio Vista,

CA

Taylor Fluid

Dampers

Total: 10

825 kN,133mm

stroke

To be

installed

2000

Seismic Seismic retrofit of

lift bridge towers to

dampen the rocking

effect during anearthquake.

Yerba Buena

Tower

USA/San

Francisco, CA

Taylor Fluid

Dampers

Total: 20445 kN,

75mm stroke

To be

installed

2000

Wind New construction,

37-story

hotel/condominiumswith dampers used

in displacement

multiplying togglebraces to improve

occupant comfort

during wind storms.

Ingram Micro USA/Santa Ana, Taylor Fluid To be Seismic Voluntary seismic


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Office

Building

CA Dampers

Total: 7490 kN,

127mm

stroke

installed

2000

upgrade to this 3-

story officebuilding. Utilizes

dampers in chevron

braces for seismic

energy dissipation.

Maysville

Bridge

USA/Maysville,

KY

Taylor Fluid

Dampers

Total: 81300 kN,

305mm

stroke

To be

installed

2000

Seismic New bridge utilizes

dampers to control

earthquakemovement and

distribute forces

while allowing free

thermal movement

111Huntington

Avenue

USA/Boston,MA

Taylor FluidDampers

Total: 1001300 kN,

101mmstroke

To beinstalled

2000

Wind New construction,38-story building

uses a combinationof direct acting

dampers and togglebrace dampers to

reduce motion

caused by windstorms.

Millennium

Place

USA/Boston,

MA

Taylor Fluid

Dampers

Total: 40

445 kN,101mm

stroke

To be

installed

2000

Wind New construction,

37-story building

uses dampers with

toggle braces toreduce motion

caused by wind

storms.

Cape

GirardeauBridge

USA/Cape

Girardeau, MO

Taylor Fluid

DampersTotal: 16

6700 kN,

180mm

stroke

To be

installed2000

Seismic New construction of

a cable-stayedbridge. Dampers

used to control

longitudinal

earthquakemovement while

allowing free

thermal movement

Route 364Page Avenue

Extension

Bridge

USA/SaintLouis, MO

Taylor FluidDampers

Total: 178

1050 kN,

To beinstalled

2000

Seismic New tied arch/plategirder bridge uses

dampers to control

longitudinal


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50mm stroke

756 kN,70mm stroke

1824 kN,

50mm stroke

2225 kN,92mm stroke

556 kN,127mm

stroke

867 kN,

127mmstroke

earthquake

movement whileallowing free

thermal movement.

Triborough

Bridge

Approaches

USA/New York,

NY

Taylor Fluid

Dampers

Total: 80445 kN,152mm

stroke

To be

installed

2000

Seismic Retrofit of the

approaches to a

suspension bridge.Dampers used tocontrol earthquake

movement and

distribute forceswhile allowing free

thermal movement.

Novelty

Bridge #404B

USA/Seattle,

WA

Taylor Fluid

Dampers

Total: 81450 kN,

100mmstroke

To be

installed

2000

Seismic Replacement bridge

project in King

County usesdampers to allow

thermal movementand restrict seismicmovements.

AmolanasBridge

Chile/Santiago Taylor FluidDampers

Total: 4

3000 kN,200mm

stroke

To beinstalled

2000

Seismic New bridge utilizesdampers to absorb

earthquake energy,

reduce movementand distribute forces

while allowing free

thermal movement.

Qinshan III

NuclearPowerplant

China/Shanghai Taylor Fluid

DampersTotal: 16

445 kN,

127mmstroke

To be

installed2000

Seismic New powerplant

uses dampers in heatexchanger for

seismic

strengthening.


7/14

Chapultepec

Tower (TorreMajor)

Mexico/Mexico

City

Taylor Fluid

DampersTotal: 98

5600 kN,

52mm stroke

2770 kN,52mm stroke

To be

installed2000

Seismic New high-rise

office/hotel toweruses dampers in

mega-braces to

dissipate earthquake

energy.

Atatrk

Airport

Turkey/Istanbul Taylor Fluid

DampersTotal: 120

45 kN, 25mm

stroke

To be

installed2000

Seismic New international

terminal with FPSisolators uses

dampers to control

deflection and

minimize thermalrestrictions.

I5/91 HOV

Bridge

USA/Anaheim,

CA

Taylor Fluid

DampersTotal: 8

1110 kN,200mm

stroke

1999 Seismic New bridge uses

dampers to dissipateearthquake energy

for reduceddemands on the

structure

Los Angeles

City Hall

USA/Los

Angeles, CA

Taylor Fluid

DampersTotal: 68

1400 kN,

600mm

stroke1000 kN,

115mm

stroke

1999 Seismic Retrofit of City Hall

building withdampers used to add

energy dissipation to

base isolation

system. Also usesdampers at 27th

floor to protect

tower from

earthquakes.

MicrosoftSilicon

Valley

Campus -

Building 1

USA/MountainView, CA

Taylor FluidDampers

Total: 15

1000 kN,

75mm stroke

1999 Seismic New construction,100,000 square foot

computer data

center with dampers

used in chevronbracing elements to

dissipate seismic

energy.

1414 K Street USA/Sacramento, CA

Taylor FluidDampers

Total: 8

1125 kN,

1999 Seismic Retrofit of anexisting office

building. Dampers

used in diagonal


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63mm stroke braces to dissipate

earthquake energy.

SanFrancisco-

Oakland BayBridge, EastSpan-Truss

Bridge


Taylor FluidDampers

Total: 6890 kN,406mm

stroke

1999 Seismic Interim retrofit ofEast Bay 504 truss

sections. Dampersused to dissipateseismic energy.

San Francisco

InternationalAirport - Rail

Transit

System

WestsideGuideway

USA/San

Francisco, CA

Taylor Fluid

DampersTotal: 10

4225 kN,

508mm

stroke3115 kN,

508mmstroke

1999 Seismic New Airport Rail

Transit (ART) andBay Area Rapid

Transit (BART)

structure implement

dampers forearthquake energy

dissipation

San Francisco

InternationalAirport -

South

InternationalParking

Garage

Pedestrian

Bridge

USA/San

Francisco, CA

Taylor Fluid

DampersTotal: 20

445 kN,

254mmstroke

1999 Seismic New pedestrian

bridge utilizesdampers to dissipate

earthquake energy

and reducemovement

TransbayTransit

Terminal


Taylor FluidDampers

Total: 36

1300 kN,

44mm stroke1300 kN,

76mm stroke

1999 Seismic Retrofit of a busterminal. Dampers

used in chevron

bracing elements to

dissipate earthquakeenergy.

Santa Clara

Police

Facility

USA/Santa

Clara, CA

Taylor Fluid

Dampers

Total: 40575 kN,

25mm stroke

800 kN,25mm stroke

1999 Seismic New police facility

utilizes dampers in

chevron bracingelements to dissipate

earthquake energy.

The

Nethercutt

USA/Sylmar,

CA

Taylor Fluid

Dampers

1999 Seismic New construction,

automotive museum


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Collection Total: 32

1500 kN,75mm stroke

1065 kN,

75mm stroke

665 kN,75mm stroke

with dampers used

in diagonal braces todissipate seismic

energy.

Sidney Lanier

Bridge

USA/Glynn

County, GA

Taylor Fluid

DampersTotal: 4

2200 kN,

203mm

stroke

1999 Seismic New bridge utilizes

dampers to controlearthquake

movement and

distribute forces

while allowing freethermal movement

Hyatt Park

Tower

USA/Chicago,

IL

Taylor Fluid

DampersTotal: 10

45 kN,500mm

stroke

22 kN,265mm

stroke

45 kN,

300mmstroke

175 kN,100mmstroke

1999 Wind New 67-story

reinforced concretestructure uses

dampers as part of aTuned Mass

Damper to improve

occupant comfortduring wind storms.

WillametteRiver

Pedestrian

Bridge

USA/Eugene,OR

Taylor FluidDampers

Total: 4

500 kN,40mm stroke

1999 Seismic/Wind

Retrofit of a bridgeover the Willamette

River. Dampers

used to control windand earthquake

movement while

allowing free

thermal movement.

Ballpark atUnion Station

USA/Houston,TX

Taylor FluidDampers

Total: 16

300 kN,153mm

stroke

1999 Wind New baseballstadium utilizes

dampers to mitigate

the effects ofhurricane force

winds on the roof


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structure.

Beijing

RailwayStation

China/Beijing Taylor Fluid

DampersTotal: 32

1300 kN,44mm stroke

1999 Seismic Retrofit of a railway

station. Dampersused in chevron

bracing elements todissipate earthquakeenergy.

New Pacific

Northwest

Baseball Park(Safeco Field)

USA/Seattle,

WA

Taylor Fluid

Dampers

Total: 361780 kN,

+100mm

stroke

890 kN,+400mm

stroke

1998/199

9

Wind/

Kinetic

Energy

Dampers installed

between three roof

sections and at endstops to absorb

energy from impact

due to wind, kinetic

energy and motordrive.

UCLA-

Knudsen Hall

USA/Los

Angeles, CA

Taylor Fluid

Dampers

Total: 84355 kN,

100mm

stroke245 kN,

100mm

stroke

1998 Seismic Seismic upgrade of

a University

building. Dampersused in chevron

bracing elements to

dissipate earthquakeenergy.

TillamookHospital

USA/Tillamook,OR

Taylor FluidDampersTotal: 30

135 kN,

50mm stroke

1998 Seismic Retrofit of anexisting hospital tomeet current seismic

protection code

levels. Dampers

used in chevronbraces to dissipate

earthquake energy.

First Avenue

South Bridge

USA/Seattle,

WA

Taylor Fluid

Dampers

Total: 4600 kN,

+635mm

stroke

1998 Kinetic

Energy

ofMoving

Bridge

Retrofit of a bascule

bridge to protect the

bascule leafs fromrunaway motors and

brake failures

New PacificNorthwest

Baseball Park

USA/Seattle,WA

Taylor FluidDampers

Total: 8

1998 Seismic/Wind

New baseballstadium utilizes

dampers to dissipate


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(Safeco Field) 3600 kN,

381mmstroke

earthquake energy

in each of threemovable roof

sections

AlaskaCommercialBuilding

USA/Alaska Taylor FluidDampersTotal: 2

445 kN,

64mm stroke

1997 Seismic Retrofit of a timberframe structure.Dampers used in

diagonal bracing to

dissipate earthquakeenergy

Hayward City

Hall

USA/Hayward,

CA

Taylor Fluid

Dampers

Total: 15

1400 kN,600mm

stroke


dampers used to add

energy dissipation to

friction pendulumbearing isolation

system

CSULA

Administratio

n Building

USA/Los

Angeles, CA

Taylor Fluid

Dampers

Total: 141100 kN,

75mm stroke

1997 Seismic Seismic upgrade to

office building.

Dampers used inchevron bracing

elements to dissipate

seismic energy.

Studio

ParkingGarage

USA/Los

Angeles, CA

Taylor Fluid

DampersTotal: 2

150 kN,50mm stroke

1997 Seismic Dampers used to

allow thermalmotion, concrete

expansion/contraction and creep, whilecontrolling

earthquake

movement

Rockwell

Building 505

USA/Newport

Beach, CA

Taylor Fluid

DampersTotal: 6

320 kN,

64mm stroke

1997 Seismic Retrofit of a long

building withmultiple expansion

gaps. Dampers

restrict relative

movement betweenbuilding sections

San Francisco

Civic Center

USA/San

Francisco, CA

Taylor Fluid

Dampers

Total: 2921000 kN,

100mm


14-story, 800,000

square footGovernment office

building with


12/14

stroke

550 kN,100mm

stroke

dampers in diagonal

bracing elements todissipate seismic

energy

Worcester'sCentrumCentre/Arena

and

ConventionComplex

USA/Worcester,MA Taylor FluidDampersTotal: 32

10 kN, 75mm

stroke

1997 Pedestrian Traffic/Dancing

Ballroom floortuned mass dampingsystem to eliminate

perceptible vibration

due to dancing inputand other potential

input motions.

Quebec Iron

and Titanium

Smelter

Canada/Tracy Taylor Spring

Dampers and

TaylorDampers

Total: 22450 kN,

64mm stroke225 kN,

100mm

stroke130 kN,

100mm

stroke

1997 Seismic/

Wind

Dual purpose spring

dampers used for

seismic and windprotection of two

smelter buildings.Dampers used to

prevent buildingsfrom impacting

during a seismic

event.

Kaiser Data

Center

USA/Corona,

CA

Taylor Fluid

DampersTotal: 16

425 kN,

560mm

stroke

1996 Seismic Seismic retrofit with

dampers used to addenergy dissipation to

rubber bearing

isolation system.

LangenbachHouse

USA/Oakland,CA

Taylor FluidDampers

Total: 4

130 kN,

150mmstroke

1996 Seismic Seismic dampersused to provide

energy dissipation in

base isolation

system.

CSUS

Science II

Building

USA/Sacrament

o, CA

Taylor Fluid

Dampers

Total: 40220 kN,

50mm stroke

1996 Seismic Seismic dampers

used in chevron

bracing of this newstructure to dissipate

seismic energy.

The Money USA/Sacrament Taylor Fluid 1996 Seismic New construction,


13/14

Store

NationalHeadquarters

o, CA Dampers

Total: 120710

kN,64mm

stroke

1290 kN,64mm stroke

pyramid shaped 11-

story officebuilding, moment

frame structure with

dampers in diagonal

braces.

Arrowhead

RegionalMedical

Center (5

buildings)

USA/San

Bernardino, CA

Nonlinear

Taylor FluidDampers

Total: 186

1400 kN,

600mmstroke


dampers used to addenergy dissipation to

rubber bearing

isolation system in

five independentlyisolated buildings.

Hotel

Woodland

USA/Woodland,

CA

Taylor Fluid

DampersTotal: 16

450 kN,50mm stroke

1996 Seismic Seismic retrofit of

four-story historicmasonry structure

with fluid dampersin chevron bracing.

28 State

Street

USA/Boston,

MA

Taylor Fluid

Dampers

Total: 40670 kN,

25mm stroke

1996 Wind Wind dampers used

in diagonal bracing

for comfort levelimprovements to a

completely

renovated high-rise

office building.

First AvenueBridge

USA/Seattle,WA

Taylor FluidDampers

Total: 4

400 kN,

+685mmstroke

1996 KineticEnergy

of

Moving

Bridge

Protection of newbascule leafs from

runaway motors and

brake failures.

Montlake

Bridge

USA/Seattle,

WA

Taylor Fluid

Dampers

Total: 4

240 kN,+483mm

stroke

1996 Kinetic

Energy

of

MovingBridge

Retrofit of a bascule

bridge to protect the

bascule leafs from

runaway motors andbrake failures.

Pacific Bell

North AreaOperation

Center

USA/Sacrament

o, CA

Taylor Fluid

DampersTotal: 62

130 kN,


three-story steelbraced frame,

dampers in chevron


14/14

50mm stroke braces used to

dissipate seismicenergy.

Petronas

Twin Towers

Malaysia/KLCC Taylor Fluid

DampersTotal: 1210 kN, 50mm

stroke

1995 Wind Kuala Lumpur City

Centre high-risetowers, part of massdamping system in

skybridge legs.

Rich Stadium USA/Buffalo,

NY

Taylor Fluid

DampersTotal: 12

50 kN,

460mm

stroke

1993 Wind Wind dampers

connect light polesto the stadium

parapet wall to

eliminate base plate

anchor bolt fatigue.

West SeattleBridge

USA/Seattle,WA

Taylor FluidDampers

Total: 6

1000 kN,

+406mmstroke

2515 kN,

+254mmstroke

1990 KineticEnergy

of

Moving

Bridge

Deck isolation forswing bridge.

NorthAmerican Air

DefenseCommand

USA/CheyenneMountain, CO

TaylorDampers

Quantity, typeand sizeclassified

1984 NuclearAttack

Classified

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