STUDY OF EARTHQUAKE ISOLATION SYSTEM.pdf

project ppt

1. GOVERNMENT ENGINEERING COLLEGE
BHOJPUR
“STUDY OF EARTHQUAKE ISOLATION SYSTEM”
DEPARTMENT OF MECHANICAL ENGINEERING
A MINOR PROJECT PRESENTATION ON
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Under the guidance of:
Prof. Samar Sultan
SUBMITTED BY:
1.Aditi Kumari
(21102156912)
2.Baiju Kumar
(21102156913)
3.Divya Darshan
(21102156919)
4.Chitranjan Kumar
(21102156922)
2021-24

2. Outline of the Presentation
1.Introduction
2.Literature Review
3.Laws and Principles applied
•Earthquake Wave Propagation
•Law of Interia (Newton’s 1
st
law of motion)
•Vibrations and Damping
•Rollers and Spherical Balls
4.Plan of Work
5.References

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3. Introduction
Tokyo [Japan], April 1 (ANI): Theearthquakethat struck the Noto Peninsula in Japan on New Year's Day is
still affecting thousands of individuals, as over 8,000 individuals continue to live inevacuation centres,
according to The Japan Times.
The thousands of individuals living inevacuation centreshave prompted experts to question why lessons
from past disasters haven't been learned.
A mild earthquake rattled the arid eastern reaches of San Diego County Monday.
The 3.0-magnitude temblor struck at 10:52 a.m. in the Carrizo Valley area, about 10 1/2 miles northeast of
Mount Laguna, according to theU.S. Geological Survey.
Representatives of Cal Fire and the San Diego County Sheriff’s Department said the agencies had received
no calls reporting any problems related to the quake.
–City News Service
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4. Introduction (contd.)
According to the recent news, we have seen that Earthquake only causes disaster and
also damage health facilities and transportation, which can disrupt service delivery and
access to care.
It causes slowing down the development and economical damage of that area.
According to who.int, between 1998-2017, earthquakes caused nearly 750 000 deaths
globally, more than half of all deaths related to natural disasters. More than 125 million
people were affected by earthquakes during this time period, meaning they were injured,
made homeless, displaced or evacuated during the emergency phase of the disaster.
Here comes our idea into effect to minimise the impact of earthquake on human life by
ensuring the isolation of buildings and workshops wherever there is a chance of collapsing
which causes human death, injury and capital loss.
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5. Literature Review
Authors Study Parameters Findings
Clemente and
Martelli , (2017)
Seismic behaviour, base
isolation, seismically isolated structures,
seismic monitoring
By the monitoring of the base isolated
structures, it can be obtained that
development of isolation is needed in
implementation of structures in future.
Dong and
Frangopol , (2015)
Structural damage
Seismic hazard, base-isolated building ,
resilience, non-structural
damage
Repair cost, fatalities and impact to the
environment can be reduced by the help
of
base isolation
Sayani and Ryan,
(2009)
Base isolation, response spectra,
nonlinear analysis, ductility,
seismic effects, performance
characteristics, structural
response, acceleration
After the response history analysis,
findings
show that force reduction factors for
seismically isolated building are less than
the fixed-base ones.
Mitropoulou and
Lagaros (2016)
Seismic isolation, life-cycle cost analysis,
performance-based design, optimization
for structure, probabilistic
dynamic loading.
Compared with the fixed structure, the
isolated structure shows a more flexible
response, in which the frequency is lower.
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6. Laws and Principles applied
Earthquake Wave Propagation
Seismic wave propagation is a ground motion phenomenon that relates to the passage of body waves, including
compression waves and shear waves, radially from the source of earthquake energy release (hypocenter) into the
surrounding rock and soil medium.
The four main types of seismic waves are P waves, S waves, Love waves, and Rayleigh waves.
During an earthquake, surface waves are the seismic waves that cause the most damage. Unlike other seismic
waves that move deep inside the Earth, surface waves move along just under the surface of the Earth like waves in
water.
It is the most dangerous natural phenomenon that generates sizable destruction in structures. It is reported that two
sources of mistakes which would seriously endanger structures are ignoring the ways an earthquake affects
buildings and shoddy construction practices.
As earthquake hits structures, it generates inertia forces which could be greatly destructive causing deformations
and, horizontal and vertical shaking.
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7. Laws and Principles applied (contd.)
Earthquake Wave Propagation
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8. Laws and Principles applied (contd.)
Law of Interia (Newton’s 1
st
law of motion)
Inertia:The tendency of an object to resist changes in its state of motion.
Newton’s first Law states that all objects have inertia. The more mass an object has, the greater its inertia
and the more force it takes to change its state of motion.
The amount of inertia an object has depends on its mass - which is roughly the amount of material present
in the object. The generation of inertia forces in a structure is one of the seismic influences that
detrimentally affect the structure. When an earthquake causes ground shaking, the base of the building
would move but the roof would be at rest. However, since the walls and columns are attached to it, the
roof is dragged with the base of the building.
The tendency of the roof structure to remain at its original position is called inertia. The inertia forces can
cause shearing of the structure which can concentrate stresses on the weak walls or joints in the structure
resulting in failure or perhaps total collapse.
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9. Laws and Principles applied (contd.)
Law of Interia (Newton’s 1
st
law of motion)
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10. Laws and Principles applied (contd.)
Vibrations and Damping
Vibration: When elastic bodies such as a spring, a beam and a shaft are displaced from the equilibrium position
by the application of external forces, and then released, they execute a vibratory motion. This is due to the
reason that, when abody is displaced, the internal forces in the form of elastic or strain energy are present in the
body. At release, these forces bring the body to its original position. When the body reaches the equilibrium
position, the whole of the elastic or strain energy is converted into kinetic energy due to which the body
continues to move in the opposite direction. The whole of the kinetic energy is again converted into strain
energy due to which the body again returns to the equilibrium position. In this way, the vibratory motion is
repeated indefinitely.
Damping: In physical systems, damping is the loss of energy of an oscillating system by dissipation. in damped
vibrations, the amplitude of the resulting vibration gradually diminishes. This is due to the reason that a certain
amount of energy is always dissipated to overcome the frictional resistance. The resistance to the motion of the
body is provided partly by the medium in which the vibration takes place and partly by the internal friction, and
in some cases partly by a dash pot or other external damping device.
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11. Laws and Principles applied (contd.)
Vibrations and Damping
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12. Laws and Principles applied (contd.)
Rollers and Spherical Balls
Bearing: It is a machine element which support another moving machine element (known as journal). It
permits a relative motion between the contact surfaces of the members, while carrying the load. A little
consideration will show that due to the relative motion between the contact surfaces, a certain amount of
power is wasted in overcoming frictional resistance and if the rubbing surfaces are in direct contact, there will
be rapid wear which can be compensated by lubrication and choosing self lubricating materials.
Bearings are manufactured to take pure radial loads, pure thrust loads, or a combination of the two kinds of
loads. Since the rolling elements and the races are subjected to high local stresses of varying magnitude
with each revolution of the bearing, therefore the material of the rolling element (i.e. steel) should be
of high quality. The balls are generally made of high carbon chromium steel. The material of both the
balls and races are heat treated to give extra hardness and toughness.
The balls and rollers are manufactured by hot forging on hammers from steel rods. They are then heat-
treated, ground and polished. The races are also formed by forging and then heat-treated, ground and
polished.
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13. Laws and Principles applied (contd.)
Rollers and Spherical Balls
Our objective to be implemented
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14. Plan of Work
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Our objective is to isolate the base of the structure by
providing a flexible interface between the superstructure
and ground foundation that can considerably reduce the
level of earthquake forces transmitted to the building.
For the implementation, 1st, the base section is splitted
into upper and bottom portion.
Then, the surface is made concave in order to provide
spacing to install the balls or rollers.
To the adjacent bases, same method is to be applied but
the radius of curvature is reduced to fill small balls
which will constraint the structure to its original
position.

15. References
1.Khurmi R.S. and Gupta J.K. , “A Textbook of Machine Design”, Eurasia Publishing House (PVT.)
Ltd. 2005
2.Khurmi R.S. and Gupta J.K. , “Theory of Machines”, S.Chand Publishing, 2005
3.Google links:
•https://en.m.wikipedia.org/wiki/Seismic_wave
• https://theconstructor.org/structural-engg/earthquake-effects-structures/2704/
• https://www.who.int/health
topics/earthquakes#:~:text=Earthquakes%20can%20have%20immediate%20and,tsunamis
%20or%20burns%20from%20fires
•https://www.sciencedirect.com/topics/engineering/seismic-wave-
propagation#:~:text=Seismic%20wave%20propagation%20is%20a,surrounding%20rock
%20and%20soil%20medium
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16. Thank You
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