Earth QuakeResisting methods

Padiga Akhilesh go6155Vaibhav Sharma go6171

CONTENTS

Introduction

Seismic Waves

Seismograph Impacts

Dampers

Shear walls

INTRODUCTION

o Shaking of earth due to movement of rocks along a fault.

o Associated with faulting or breaking of rocks

o Rocks under stress accumulate strain energy and breaks.

WHAT IS AN EARTH QUAKE?

Focus & Epicenter

FOCUS:

The point within Earth where faulting begins is the focus, or hypocenter

EPICENTER:

The point directly above the focus on the surface is the epicenter

FOCAL DISTANCE:

Vertical distance from focus and epicenter

Seismic wavesThe waves that causes vibrations on earth are seismic waves

Types of seismic waves

1. Body Waves travel through interior

1.1 Primary or "P" Waves:oHighest velocity oCauses compression and expansion

1.2 Secondary or "S" Waves:oSlower than P waves but faster than surface waves. oCauses shearing of rock perpendicular to direction of wave

S & P Waves Trend

2. Surface Waves or "Love" (“L”) Waves otravel on surface of earthoCause vertical & horizontal shakingoCause maximum damage

Where Do Earthquakes Occur and How Often?

o 80% occur in the circum-Pacific belto ~15% occur in Mediterranean-Asiatic belto Remaining 5% occur in the interiors of plateso More than 150,000

quakes strong enough to be felt are

recorded each year

Indonesia after Tsunami 2004

Tectonic Plates

MEASUREMENT OFEARTH QUAKE

Magnitude

Richter scale measures total amount of energy released by an earthquake

Amplitude of the largest wave produced by an event is corrected for distance and assigned a value on an open-ended logarithmic scale

Intensity

Modified Mercalli Intensity Map 1994

Northridge, CA earthquake, Magnitude 6.7

oIntensity refers to the amount of damage done in an earthquake

oMercalli Scale is used to express damage

Normal type seismograph

Digitalize type seismograph

Seismograph

Vertical type

Horizontal type

SEISMOGRAM

DEMO OF SEISMOGRAPH

Location Of EPICENTER

Three seismograph stations are needed to locate the epicenter of an earthquake

A circle where the radius equals the distance to the epicenter is drawn

The intersection of the circles locates the epicenter

An example

Impact of Earthquakes

Building collapse

Land slides

Land cracking

Liquefaction

Apartment, Niigata in 1964

Tsunami

RESISTING METHODS

Consider a Coconut Tree

Weak joints

LIQUEFACTION

Avoid the Site

SEISMIC DAMPERS

Torsional Mass Damper(TMD)

Taipei-101

Viscous dampers inSan Francisco Civic Center

1997

Friction damper

Yielding dampers

SHEAR WALLS

LOCATION OF SHEAR WALL

CLASSIFICATION

Simple rectangular type Coupled Rigid frame Framed

Column supported shear wall

Core type

Types of SHEAR WALLS

RC SHEAR WALL

PLYWOOD SHEAR WALL

MID PLY SHEARWALL

RC HOLLOW CONCRETE BLOCK MASONRY WALLS

STEEL SHEAR WALL

ConclusionoEarth quake don’t kills but the structures kills

oDamage can be reduced using latest techniques and technologies

oThough structure may damage but we can save OUR LIFES..!!

Thank You

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