Earthquakes are sudden movements of the earth caused by tectonic stresses, leading to significant casualties and structural damage. Civil engineering solutions, such as base isolation and strengthening techniques, aim to protect structures from earthquake forces and minimize damage. Base isolation systems, including flexible rubber pads and friction pendulum bearings, reduce energy transfer to buildings and enhance their resilience during seismic events.

1. WHAT IS
EARTHQUAKE ?
QUE:
 ANY PEOPLE DIED DUE TO EARTHQUAKE?
• sudden movement or shaking of the Earth
• Caused by plate tectonic stresses
• Located at plate boundaries
• Resulting in breakage of the Earth’s brittle crust

2. CASE STUDY:
QUE:
 ARE WE ABLE TO RESIST EARTHQUAKE?
• On the average about 10,000 people die each year
as a result of earthquakes.

3. SO AS A CIVIL ENGINEER WHAT WE DO FOR THIS
SOCIETY :
 Proper design. (increase ductility of structure)
• Increase ductility of beam – column joint
• Strengthening of individual footing.
 Give any mechanical provisions to the building to withstand in earthquake.
• Shear walls
• Bracing
• Dampers
• Rollers
• “Base Isolation of structure”.

4. BASE ISOLATION OF
STRUCTURE:

5. WORKING METHOD OF BASE ISOLATION

6. BASE ISOLATION USING FLEXIBLE RUBBER PADS
• Base isolation is a passive vibration control system.
• The goal of base isolation is to reduce the energy that is transferred from the ground
motion to the structure.
(a) Conventional structure (b) base isolated structure.

7. ISOLATION

8. EFFECTS OF BASE ISOLATION SYSTEM

9. IMAGE OF BASE ISOLATION

10. SPHERICAL SLIDING BASE ISOLATION
• Spherical sliding isolation systems are another type of base isolation.
The building is supported by bearing pads that have a curved surface
and low friction.
• During earthquake, the building is free to slide on the bearing. Since
the bearing have a curved surface the building slides both vertically
and horizontally.

11. FRICTION PENDULUM BEARING:
• These are specially designed base isolators which works on the principle of simple
pendulum.
• It increase the natural time period of oscillation by causing the structure to slide along the
concave inner surface through the frictional interface.
• Its also possesses a re-centering capability.

12. ADVANTAGE OF BASE ISOLATION:
• Structural Damage restricted.
• No Damage to indoor services and facilities(gas or water pipelines).
• Protects the structure by preventing plastic deformation of structural elements.
• Secondary damage (Falling furniture) is restricted.
• Function of buildings is ensured as super structure is designed to remain elastic
even after an earthquake happens.
• Deflections and stresses generated are lower.
• Allows for a reduction in structural elements of buildings with less ductile detailing
needed.

13. RECALL:-
• Base isolation is a passive vibration control system.
• Its control the earthquake force transmit to the building or structure.
• Three types
 isolation by flexible rubbers.
Spherical Sliding Base Isolation
Friction pendulum bearing
• Main advantage – Structural Damage restricted

14. THANK YOU…
• “Engineers like to solve problems. If there are no problems
handily available, they will create their own problems.”
― Scott Adams