This document discusses techniques for making structures resistant to earthquakes, including base isolation and energy dissipation devices. Base isolation involves separating the building from the ground using flexible rubber devices to allow it to move independently during an earthquake. Energy dissipation devices, like seismic dampers, absorb seismic energy to dampen the motion of the building. Common types of base isolators are lead rubber bearings and spherical sliding isolators, while common seismic dampers include viscous, friction, and yielding dampers. Proper seismic design involves principles like avoiding brittle elements, providing strength throughout the building, and well-connecting the building to its foundation.

1. EARTHQUAKE RESISTING
STRUCTURES
BY- VARUN

3. EARTHQUAKE RESISTING STRUCTURES
TECHNIQUES
Base Isolation Method- separate building from
ground by some rubber devices.
Energy Dissipation Device (Seismic Dampers)-
Special devices introduced in building to
absorb the energy produced by seismic
waves.

4. BASE ISOLATION
Introduces flexibility to the
structures.
Building is rested on flexible
pads (Base Isolators).
When earthquake strikes the
building does not moves.
It is suitable for hard soil only.

5. TYPES OF BASE ISOLATOR
Lead Rubber Bearing:-
Frequently used for base
isolation.
Made from layers of rubber
sandwiched together with layers
of steel.
Very stiff and strong in the
vertical direction.
Flexible in horizontal
direction.

6. Spherical Sliding Isolator
It uses bearing pads that
have a curved surface and
low-friction materials.
During an earthquake the
building is free to slide both
horizontally and vertically
 It will return to its
original position after the
ground shaking stops.

7. ENERGY DISSIPATION DEVICE
• These are used in place of structural elements
such as diagonal braces
• Acts like the hydraulic shock absorbers in cars
• When seismic energy is transmitted through
them, dampers absorb part of it, and thus
damp the motion of the building.

8. TYPES OF SEISMIC DAMPERS
Viscous Dampers (energy is
absorbed by silicone-based fluid
passing between piston cylinder
arrangement)
 Friction Dampers (energy is
absorbed by surfaces with
friction between them rubbing
against each other)
 Yielding Dampers (energy is
absorbed by metallic components
that yield)

9. SEISMIC DESIGN
General Principles of Seismic Design:
Structures should not be brittle or collapse
suddenly.
Resisting elements must be provided evenly
throughout the building.
All elements such as walls should be tied
together so as to act as an integrated unit
during earthquake shaking.
The building must be well connected to a
good foundation and the earth.

10. SEISMIC DESIGNING
• Planning stage
– Plan building in symmetrical way (both axis)
– Avoid weak storey and provide strong diaphragm
– Conduct soil test to avoid soil liquefaction
– Simple Design

11. • Design stage
– Avoid weak column and strong beam design.
– Provide thick slab which will help as a rigid
diaphragm. Avoid thin slab and flat slab
construction.
– Provide cross walls which will stiffen the
structures in a symmetric manner.
– Provide shear walls in a symmetrical fashion.
•Construction stage
- Compact the concrete by
means of needle vibrator.
- Cure the concrete for at
least a minimum period.

12. SHEAR WALL
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.