By M. Mayur

IVth CIVIL - SIETK,PUTTUR.

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Structure of EarthEarth - three layers - Crust, Mantle, Core.Crust - surface of Earth, Mantle – second

inner part of the Earth, Core - most inner part of the Earth.

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What are Earthquakes? • sudden movement - surface of the earth - may

be tiny or several feet.

• enormous amounts - of energy released – greater - Nuclear Bomb.

• sudden shift of rock - fracture of Earth.

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Earthquakes - Plate Tectonic Forces.

Theory of Plate tectonic forces -

He stated that continents moved from their original

position - Continental Drift.

Origin of Earthquakes

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Different boundaries - tectonic forces induces Earth:

Divergent boundary, Convergent, Transform boundaries.

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SeismologyWhen earthquakes occur, waves travel in Earth in

form of vibrations, such waves are called Seismic Waves.

Study of such waves - Seismology.

Instrument measuring seismic waves - Seismometer.

Graphs given by that seismometer - Seismic Graph.

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Terms of EQ’s:

Seismic Loading : Main cause of Earthquakes

Seismic Performance : Structure’s ability - functions - safety and serviceability - exposure - earthquake.

Seismic Analysis : Major intellectual tool – understand seismic performance of structures.

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Earthquakes affect

RCC structures too…

Slabs forces the beam

to bend with it when

horizontal forces act.

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Earthquake resistant designs

Design - but it is analysis of forces - buildings due to loads acting on it.

If a building is enough to resist the earthquake, then such building is called Earthquake resistant structure.

Such design is called Earthquake resistant designs

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Popular Earthquake resistant Techniques

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Introduction of Resistant techniques

Thought - Base Isolation Devices - separate building from ground by some rubber devices.

Seismic dampers - special devices - introduced in building - absorb the energy - produced by seismic waves.

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Base Isolation Devices

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Base Isolation DevicesBase isolation Devices - Active Control System

which contains:• Sensors - measure external excitation - structural response. • Computer hardware and software - compute control forces – observed excitation. • Actuators – provide – necessary control forces.

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Control Force Devices

Active Tuned Mass Dampers - natural extension – experiments indicate 25% less damage.

Tendon Control – used even for active devices – works when active devices are off – act by resisting tension in structure.

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Seismic Dampers

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SD’s in structures:

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Dampers are of:

Viscous Damper Friction Damper Yielding Damper

Note points: BID SD’S separating structures

from ground by means of devices.

Can be done when structure is already constructed, but it is costly.

Cheaper compared to Seismic Dampers.

additional systems introduced in structures.

even when structure is completed, systems can be introduced.

Very costly, since linked with hardware programmes.

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Frames Resisting EQ’

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Increase in Seismic PerformanceQuality Control in Construction.

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CONCLUSIONWe are only hope of tomorrow’s

constructions.

WE ARE HERE ONLY TO PROVIDE SAFETY TO PUBLIC TO LEAD THEIR LIFE

HAPPILY.

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THANK YOU…

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