2. Syllabus
▪ Unit#1: Natural Disasters (3 Lectures): Earthquake, Floods, Drought, Coastal Hazards, Landslides,
rockslides and Forest Fires.
▪ Unit#2: Elements of Engineering Seismology (4 Lectures): Earthquake phenomenon, Earthquake
recording instruments.
▪ Unit#3: Introduction to Theory of Vibrations (4 Lectures): Single degree un-damped and damped
systems, elastic response to simple load functions and earthquake response spectras.
▪ Unit#4: Performance of Buildings and Structures (4 Lectures): Main causes of damage: Intensity of
earthquake forces, lack of strength and integrity in buildings, quasi- resonance, lack of ductility, lack of
detailing.
▪ Unit#5: Earthquake Effects (4 Lectures): On ground and soil liquefaction, buildings, structures, power
plants, switch yards, equipment and other lifeline structures, release of poisonous gases and radiation.
▪ Unit#6: Lessons Learnt from the Past Earthquakes (3 Lectures): Case studies of important Indian
earthquakes and major world earthquakes.
▪ Unit#7: Disaster Management (4 Lectures): Salient features of disaster rescue, risk management and
casualty management.
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3. Content of Today’s Lecture
▪ Unit#1: Natural Disasters (3 Lectures): Earthquake, Floods, Drought, Coastal Hazards, Landslides,
rockslides and Forest Fires.
▪ Unit#2: Elements of Engineering Seismology (4 Lectures): Earthquake phenomenon, Earthquake
recording instruments.
▪ Unit#3: Introduction to Theory of Vibrations (4 Lectures): Single degree un-damped and damped
systems, elastic response to simple load functions and earthquake response spectras.
▪ Unit#4: Performance of Buildings and Structures (4 Lectures): Main causes of damage: Intensity of
earthquake forces, lack of strength and integrity in buildings, quasi- resonance, lack of ductility, lack of
detailing.
▪ Unit#5: Earthquake Effects (4 Lectures): On ground and soil liquefaction, buildings, structures, power
plants, switch yards, equipment and other lifeline structures, release of poisonous gases and radiation.
▪ Unit#6: Lessons Learnt from the Past Earthquakes (3 Lectures): Case studies of important Indian
earthquakes and major world earthquakes.
▪ Unit#7: Disaster Management (4 Lectures): Salient features of disaster rescue, risk management and
casualty management.
CE-462: Disaster Mitigation & Earthquake Engineering 3
4. Introduction to Earthquake
▪ Definition: Phenomena of sudden slips on the fault and consequently ground
shaking and radiation of seismic energy caused by the slip of volcanic activity or
other sudden stress changes in Earth.
▪ Hypocentre or Focus: Point withing the Earth where an earthquake rupture
initiates.
▪ Epicentre: Point on the Earth surface vertically above the focus in the crust
where seismic rupture begins.
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5. Introduction to Earthquake
▪ Earthquake Hazard: describes the way in which an earthquake disrupt the day
to day life of people- surface faulting, ground shaking, landslide, liquefication,
tsunami, etc
▪ Earthquake Risk: Probable damage to buildings and civil structures and severity
at which it will affect the people
▪ Earth Layers:
▪ Crust: thin outermost layer of Earth, mainly comprise of solid rocks
▪ Mantle: consist of solid rocks and a layer of molten rock called magma of temp higher
than 2000o C.
▪ Core: innermost part of the earth with temperature higher than 3000oC
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8. Earthquake waves
▪When there is rupture, the sides of the
fault rub against one another so that a
considerable energy is expanded by
frictional forces and crushing of the
rock and consequently surfaces are
heated. As the consequences,
earthquake waves are generated at
the same time by the rebounding of
the adjacent sides of the fault at the
surface and by rubbing and crushing.
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9. Characteristics of ground motion
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Surface Faulting is the offset or tearing of the earth surface
Tectonic Uplifting: major differential vertical and horizontal movement over broad parts of the
Earth’s surface within a few meters to hundred meters from the fault.
Landslides: When earth moves along a slip plane under the influence of gravity
Quickclays: clays lose shear-strength when disturbed by ground shaking. Alaska Earhquake 1964
Liquefication: clay-free soil deposits, primarily sand and silts temporarily lose strength and behave
like viscous fluid rather than solid. Niigata Earthquake 1964
10. CE-462: Disaster Mitigation & Earthquake Engineering
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Massive landslide blocks Shimla-Kinnaur highway
Damage due to liquefaction during Niigata Earthquake 1964
Surface rupture of the 2016 Kumamoto Earthquake
11. Measurement of Earthquake
▪ Magnitude: is a measure of strength of an earthquake in the vibration energy of
the shock or strain energy release by it at its source.
▪ In 1935, seismologist Charles F. Richter first defined the local magnitude as the
logarithm to the base of 10 of the amplitude of the seismic wave that would be observed
on a standard torsion seismograph at the distance of 100km from epicentre.
▪ Intensity: is a measure of the observed effect of the earthquake on man,
buildings and earth surface at a particular location.
▪ First intensity scale was developed in Europe in 1833 by M.S. Rossi of Italy and F.G. Forel of
Switzerland with 1 to 10 level
▪ In 1902, Ginseppe Mercalli scale was introduced with 10 grades of intensity and later modified to
have 12 grades, which is widely used
▪ Medvede-Sponheur-Karnik (MSK) scale of 1964 also has 12 grades of intensity
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12. Seismic Zonation
Dividing a region into several seismic
zones based upon the seismicity
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13. Seismic Micro-Zoning
▪ Micro-zonation is modern device by having high precision grid into which the area of
a region is divided for increasing the predictability of the earthquake hazard.
▪ Some of the perceived hazards
▪ Building collapse and damage to structures due to earthquake induced ground motion
▪ Liquefaction failure
▪ Slope instability associated with natural slopes
▪ Failure of earth retaining structures
▪ Avalanches, rockfalls and associated damages
▪ Deferential ground settlement
▪ Earthquake triggered fire
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14. Seismic Micro-Zoning
▪ Geological aspects shall be given prominence
▪ Regional tectonics and pattern of deformation
▪ Mapping of significant faults within 100-150 kms of the site map
▪ Determination of fault types
▪ Evidence and observations reflecting on recent displacement history of fault
▪ Location of any landslide, ground settlement, water inundation and similar problems
from seismicity
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15. Seismic Micro-Zoning
▪ Steps involves
▪ Selection of design hazard level
▪ Regional geological and geo-technical studies
▪ Evaluation of sub surface profiles in the area of interest
▪ Assessment of characteristics of design earthquake
▪ Analysis of seismic site response within the zone mapped
▪ Assessment of seismic hazard with special reference to liquefaction potential and
structural damage arising from the site amplification of the earthquake bedrock motions.
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16. Structural design aspects
▪ Design characteristics of earthquake loading
▪ Uncertainty associated with amplitude, duration and frequency of loading
▪ Capacity to withstand vertical loads due to gravity
▪ Capacity of withstand lateral loads due ti horizontal earthquake ground motion
▪ Dynamic loading produces responses concerning inertial and elastic forces and other
energy dissipation damping mechanism.
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17. Structural design aspects
▪ Design strategy to meet requirement of minor and major tremor
▪ The inelastic deformation due to ductility and hysteric energy dissipation to withstand
and resist from collapse due to earthquake consistent with seismic demand
▪ Proper weightage shall be given to soil and foundation conditions for earthquake
resistant design
▪ Analysis pertaining to elastic and inelastic response spectrum analysis, time-history
dynamic response analysis and seismic behaviour of various materials used in
construction are given relevant consideration
▪ Quality control of construction materials, construction practices shall be given proper
consideration.
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18. Summary of the lecture
▪ Introduction to earthquakes
▪ Earthquake waves
▪ Magnitude and intensity of earthquake
▪ Seismic zonation
▪ Seismic micro-zoning
▪ Structural design aspects in earthquake loading
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