7. July 2014

Architecture
doors, almirahs, mirrors etc.
• Stay away from falling plaster, bricks
or stones.
• Get under a table or a sturdy cot so
that you are not hurt by falling objects.
• Do not rush towards the doors or
staircase. They may be broken or
jammed.
If you are outdoors at the time of
earthquake,
• If open space is available nearby, go
there.
• Keep away from tall chimneys, buildings,
balconies and other projections.
• Do not run through streets; hoardings
or lamps may fall on you.
After an earthquake
• Check if you or anyone else is hurt.
Use first aid at least on the cuts and
bruises.
• Keep the streets clear for emergency
services.
• Switch off all appliances like the refrigerator,
TV or radio. Turn off the gas.
• Wear shoes to protect your feet from
debris.
• A battery operated radio will help you
to get important messages.
• Be prepared for more shocks.
These aftershocks always follow an
earthquake.
Avoid the following in an earthquake
• Do not crowd around damaged areas
or buildings.
• Do not waste water. It will be needed
for fire fighting.
• Do not move the seriously hurt
people.
• Wait for medical help to arrive.
• Do not spread rumors. They lead to
panic and worsen the situation
Philosophy of Earthquake
Resistant Design
Engineers do not attempt to make
earthquake proof buildings that will not
get damaged even during the rare but
strong earthquake; such buildings will
be too robust and also too expensive.
Instead the engineering intention is to
make buildings earthquake-resistant;
such buildings resist the effects of
ground shaking, although they may
get damaged severely but would not
collapse during the strong earthquake.
Thus, safety of people and contents is
assured in earthquake-resistant buildings,
and thereby a disaster is avoided.
This is a major objective of seismic
design codes throughout the world.
Design Philosophy
a) Under minor but frequent shaking,
the main members of the buildings
that carry vertical and horizontal forces
should not be damaged; however
buildings parts that do not carry load
may sustain repairable damage.
b) Under moderate but occasional
shaking, the main members may
sustain repairable damage, while
the other parts that do not carry load
may sustain repairable damage.
c) Under strong but rare shaking, the
main members may sustain severe
damage, but the building should not
collapse.
Earthquake resistant design is therefore
concerned about ensuring that the
damages in buildings during earthquakes
are of acceptable variety, and also that
they occur at the right places and in right
amounts. This approach of earthquake
resistant design is much like the use of
electrical fuses in houses: to protect the
entire electrical wiring and appliances in
the house, you sacrifice some small parts
of electrical circuit, called fuses; these
fuses are easily replaced after the electrical
over-current. Likewise to save the
building from collapsing you need to allow
some pre-determined parts to undergo
the acceptable type and level of damage.
Earthquake resistant buildings, particularly
their main elements, need to be built
with ductility in them. Such buildings
have the ability to sway back-and-forth
during an earthquake, and to withstand
the earthquake effects with some damage,
but without collapse.
1. Structure should remain essentially
elastic in frequent minor ground
shaking
2. Structure should be able to resist
occasional moderate ground shaking
without significant damage
3. Structure should be able to resist
major earthquakes without collapse
Difference between Normal Load and
Lateral Load Design
1. In Ordinary Load (dead/ Imposed,
wind etc), it is expected that structure
will essentially remain elastic even
during severe most design loading
2. Where as in earthquake resistant
design it is expected that structure
could go in inelastic regime and suffer
severe damage during a major
earthquake
We thrive for Earthquake resistant design
& construction not Earthquake proof
1. Buildings and other structures are
designed for much lesser load than
imparted by large earthquakes for affordability
and also large earthquakes
are rare.
2. Properly designed Buildings has
Ductility, Redundancy.
3. Building has over strength due to
considered safety factors in loads and
materials.
Ductility: It is the capacity of an element
or structure to undergo large inelastic
deformation without significant loss of
strength and stiffness. Ductility depends
upon:
• Construction material
• Quality of detailing
• Form of structure
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