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212 Ketter Hall, North Campus, Buffalo, NY 14260 www.civil.buffalo.edu Fax: 716 645 3733 Tel: 716 645 2114 x 2400 Structural Control through Base Isolation Andrei M Reinhorn Professor of Structural Engineering. Modern Methods in Earthquake and Vibration Mitigation.
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212 Ketter Hall, North Campus, Buffalo, NY 14260 www.civil.buffalo.edu Fax: 716 645 3733 Tel: 716 645 2114 x 2400 Structural Controlthrough Base Isolation Andrei M Reinhorn Professor of Structural Engineering
Spectral Response Target Period 2-3sec
Steel-Laminated Elastomeric Bearings Curtesy Scougal Rubber, Seattle, WA
Liquid Natural Gas (LNG)Tanks • Friction Pendulum System • 212 Isolators • -20oC - 30oC • 1000 tons capacity • 5% friction • +/-30 cm lateral movement • period of 2.75 sec
Hayward City Hall, CA 53 FPS 15 Taylor Fluid Dampers Period 3.0 sec 3.5% Friction +/-28 cm movement 900 tons capacity
22 FPS 5 sec period +/- 1.30 m movement 2200 tons capacity R=6.2m
San Francisco Airport International Terminal 267 FPS 3 sec period +/- 60 cm movement 3000 tons capacity
Court of Appeals San Francisco CA Building Retrofitted with 256 Isolators of type Friction Pendulum System
Historic Monument Suffered Damage in 1989 Loma Prieta Earthquake
Installation of FPS Cutting hole for jacks and column removal Construction of Side Beams
Installation of damper Damper in place and grouted to receive load Cutting the wall along the building
Court of Appeals- Retrofit of Interior Walls Protected During Construction Interior After Retrofit
Elastomeric Bearings Properties Horizontal Stiffness A t tr = net rubber thickness Vertical Stiffness Circular Bearing Square Pad Holed Circular Pad for strip for circular for square
Elastomeric Bearings Properties Moment Capacity of Circular Pad Effective Stiffness for Circular Pad (EI)eff = Ec R4/12 Effective Stiffness for Square Pad Effective Stiffness for Holed Pad Effective shear strain
Modified Stiffness- Modified Stiffness for Large S K - bulk modulus of material For Circular Pad Large S For Circular Pad - Small S Modified Stiffness for Very Large S
Friction Pendulum System W Force Resistance D Horizontal Stiffness Basic Period Effective Stiffness
Design Analysis 3D-Basis-Tabs series of computer programs available Report 95-0011* and Program http://civil.eng.buffalo.edu/israeli_engineers SAP2000 available from Computers and Structures, Berkeley, CA IDARC-BRIDGE from University at Buffalo /MCEER Report #98-0011* and Program http://civil.eng.buffalo.edu/idarc-bridge/ (program requires SUN / UNIX computer) * Reports can be obtained from MCEER / University at Buffalo Publications department
212 Ketter Hall, North Campus, Buffalo, NY 14260 www.civil.buffalo.edu Fax: 716 645 3733 Tel: 716 645 2114 x 2400 THANKS FOR YOUR ATTENTION