6. Conclusion
The benefits of implementing base isolation in the 40-story
steel office building were clearly shown by the results of this
study, including:
Reduction of floor accelerations, in-story drifts and base
reactions by more than 90% percentage.
Improvement of structural seismic performance levels.
Lowering the coefficients of friction of the TFP bearings
is the most effective way to improve seismic
performance (i.e. reduce the superstructure’s response
values, including floor accelerations and in-story drifts)
when implementing base isolation in a tall, flexible
building.
Using TFP bearings with larger radii of curvature (R)
leads to a more flexible (smaller lateral stiffness)
isolation system and improves seismic performance,
although larger bearing sizes are also more expensive.
Isolator system efficiency in decreasing story
displacement, in-story drift, story acceleration and base
reactions was directly proportional to earthquake
magnitude; and if two EQ have the same magnitude,
then efficiency of isolator was reversely proportional to
motion acceleration.
Isolator system efficiency in decreasing base reactions
was higher than its efficiency in decreasing in-story drift,
story acceleration.