Earthquake & Earthquake Resistant Structure Incorporating

Base Isolation Technique

Group Members:

Vardhaman Sethia(G05146)&

Prateek Jain(G05131)

Index

1. Earthquake : an overview

2. Elastic rebound theory

3. Seismic Zones in India

4. Motion During earthquake

5. Various earthquake resistant techniques.

6. Base isolation: detailed explanation

7. Questions and queries.

Elastic Rebound Theory

• Large elastic energy is stored in the rocks due to bending.

• A sudden movement occurs along the fault, releasing the accumulated energy, and the rocks snap back to their original undeformed shape.

Effect on column during Earthquake

Recent Example of Earthquake

Date Place Magnitude

26 January 2001 Gujrat 7.7

3 November 2002 Alaska(USA) 7.9

25 September 2003 Japan 8.3

26 December 2004 Sumatra, Indonesia 9.1

11 March 2011 Japan 9.0

Various Techniques used in Earthquake Resistant Structures

Conventional methods:• By constructing shear wall, shear core and cross

bracing system.

Emerging Trend:• Base Isolation System.

Base Isolation

One of the most significant developments in earthquake engineering in the past 15 years.

It provides the design profession the ability to design a building that is “operational” after a major earthquake.

BASE ISOLATED BUILDING

Concept of base isolation

Base Isolation in Buildings

Isolator Components Between the Foundation and Superstructure

An Isolation Interface is formed

Consequence of using base isolator during earthquake

KEY POINTS

• During the vibrations, the isolated base absorbs the stresses that are induced due to the restrained movement of the tectonic plate.

• It is seen that the isolated base are capable enough to keep indicted the superstructure.

• The base isolator moves in the direction of the acceleration caused by the movement of tectonic plate ,but there is corporately less swaying action of the superstructure, resulting in less susceptibility towards destruction caused and its consequences.

• During a Richter 8.0 Earthquake a Seismically Isolated Building Will Behave as if it Were Experiencing a 5.5 Earthquake

CONCLUSION

The size of the earthquake on the Richter scale does not mean there will be more damage and destruction. What is more important is how well educated people are at responding to earthquakes and how much money can be spent on making buildings, bridges, pipes etc…able to respond to the ground movements.