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

Construction of Side Beams

Cutting hole for jacks and column removal

Installation of damperDamper 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

Ball-in-Cone Isolator - Tekton Dev., Arizona

Wire Rope Isolators

Elastomeric Bearing Models

2R

t

Elastomeric Bearings Properties

Horizontal Stiffness

Vertical Stiffnesstr = net rubber

thickness

A

t

Circular Bearing

Square Pad

Holed Circular Pad

for strip

for circular

for square

Elastomeric Bearings Properties

Moment Capacity of Circular Pad

Effective Stiffness for Square Pad

Effective Stiffness for Holed Pad

Effective shear strain

Effective Stiffness for Circular Pad (EI)eff = Ec R4/12

Modified Stiffness-Modified Stiffness for Large S

Modified Stiffness for Very Large S

For Circular Pad - Small S

For Circular Pad Large S

K - bulk modulus of material

Lead Rubber Bearings

Friction Pendulum System

D

W

Force Resistance

Horizontal Stiffness

Effective Stiffness

Basic Period

Friction Pendulum System

D

W

Design Procedure

Design Procedure

Design Procedure

Design Procedure