This document discusses base isolation as a seismic protection technique. It explains that base isolation systems reduce building vibrations during earthquakes by inserting special bearings between the building and its foundation that allow for horizontal movement. There are different types of bearings used, including rubber bearings and friction pendulum bearings. Base isolation provides significant benefits like protecting the building frame, contents, and allowing the building to remain operational after an earthquake by reducing forces on the structure. It has been widely used since its first application in the 1970s and provides protection against earthquake and blast loads.

2.  Base Isolation
 Fiber Wrap
 Dampers
 Steel Moment Frame Solution
 Capacity Design principles
In general what’s good for earthquake
design helps resist blast loads

3. Base isolation systems reduce building
vibrations during earthquakes.
Normally, a building is supported directly on
its foundation, and it is said to have a fixed-
base. When base isolation is used, special
structural bearing are inserted between the
bottom of the building and its foundation.
These bearings are not very stiff in the
horizontal direction, so they reduce the
fundamental frequency of vibration of a
building.

4. 4
During an earthquake, a fixed-base
building can sway from side to side.
When a base isolation system is used,
the sideways movement occurs mainly
in the bearings
There are many types of bearings
used for base isolation. Here are two
of them.
Seismic isolation and damping can
reduce force and displacement
demands so structure remains elastic
or “damage free”

5.  Protection of Life
 Additional benefits of Isolation
 Protection of Building Frame
 Protection of Non-structural
Components and Contents
 Protection of Processes and Function
 Provide for an Operational facility after
the Earthquake.

6. During a Richter 8.0 Earthquake a
Seismically Isolated Building will Behave
as if it were Experiencing a 5.5
Earthquake

8. 8
 Rubber bearing are made from layers of rubber
with thin steel plates between them, and a thick
steel plate on the top and bottom.
 The bearings are placed between the bottom of a
building and its foundation.
 The bearings are designed to be very stiff and
strong for vertical load, so that they can carry the
weight of the building. However, they are designed to
be much weaker for horizontal loads, so that they
can move sideways during an earthquake.

10. 10
 Friction pendulum bearing are made from two
horizontal steel plates that can slide over each other
because of their shape and an additional articulated
slider.
 They are designed to be very stiff and strong for
vertical load , so that they can carry the weight of
the building.

12.  1st application in New Zealand in 1974.
 1st US application in 1984
 1st Japanese application in 1985.
 1st Indian application in 2001.
(Bhuji Hospital, Gujarat Province, India)
Structural engineers Dunning Thornton
Consultants from Wellington were part of the
New Zealand design team and supervised
installation of the first bearings on site in late
2001. Eventually, 280 lead-rubber bearings were
installed.

13.  Base Isolation provides the highest level of
Protection – ‘Operational’ – after a major
earthquake.
 Base isolation has significant benefits for
the earthquake protection of historic
structure.
 Base Isolated building are capable of
resisting GSA blasts loads and their ability to
move reduces the overall impact of the blast
force on the building.

14. Passive isolation techniques have been widely
applied to many structures, and those promise a
certain level of control performance. The
structural control application using passive
isolations is able to reduce the story drifts but
still induce the floor accelerations. To enhance
the advantages of passive isolations, a hybrid
control technology can be applied. The study
presents the realization of this idea that a
building model is isolated with the bearings and
controlled by actuators in two different
directions.

15.  Chopra.R, Kumar.R, Chawla.K.S, T.P.Singh,
“Traditional Earthquake Resistant Houses”, Honey
Bee, Vol 11&Vol 12,Oct 2000-Nov 2001.
 Deodhar.S.V, Dubey.S.K, “Remedial Measures
Against Earthquake disaster”, National Building
Material and Construction World, Vol 2, Jan 2003.
 Ramallo, J. C., Johnson, E. A., and Spencer, J. F.,
“Smart base isolation system,” Journal of
Engineering Mechanics,128(10), 1088-1099 (2002).
 Indian Standard IS 1893-20