.

2. Why buildings fall
down in earthquakes
Building materials are
strong in compression,
but weaker in tension
Unreinforced brick
is vulnerable

3. Reinforced concrete buildings can collapse
if columns fail

5. Containment reinforcement
Link/tie
Wall with Link Tie
Masonry with containment reinforcement and links/ties connecting them
through bed joints.

6. Diaphragms

7. Cross Bracing and Shear Walls
• Cross-bracing, which uses
two diagonal members in
an X-shape, is a popular
way to build wall trusses.
• Instead of braced frames
or in addition to them,
engineers may use shear
walls -- vertical walls that
stiffen the structural
frame of a building and
help resist rocking forces.

8. Vertically oriented wide beams.
 It carries seismic loads down to the
bottom of foundation.
 Provides large strength and stiffness
to buildings.
Should be symmetrical in plan along
both the axes.
Effective when located along the
exterior perimeter of building.

10. Moment Resisting Frames
• In these structures, the
columns and beams are
allowed to bend, but the
joints or connectors
between them are rigid. As
a result, the whole frame
moves in response to a
lateral force and yet
provides an edifice that's
less obstructed internally
than shear-wall structures.

11. Base Isolation
• Another solution -- known as base isolation -
- involves floating a building above its
foundation on a system of bearings, springs
or padded cylinders.

19. Active Mass Damping

20. Liquid Tuned Mass Damper