International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056
Volume: 04 Issue: 05 | May -2017 www.irjet.net p-ISSN: 2395-0072
© 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 1839
Comparative Analysis on Response of a School Building against Gravity,
Earthquake and Tsunami forces
P. Subhash Bhargava
1
, A.H.L.Swaroop
2
1
Post Graduate student, Gudlavalleru Engineering College, Gudlavalleru, India.
2
Sr. Gr. Assistant Professor, Dept. of Civil Engineering, Gudlavalleru Engineering College, Gudlavalleru, India.
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Abstract –: A series of seismic waves in water is known as
Tsunami. These waves are caused due to the displacement of
water in oceans, large lakes,, volcanic eruptions, earthquakes
and underwater explosions and other interruptions above or
below the water will generate Tsunami. When reaching
towards the coastal depths height of the wave increases. The
main objective is to analyse a school building against gravity,
earthquake and Tsunami forces. To analyse the building forces
due to gravity, earth quake and Tsunami are calculated for
different inundation depths and considering the obtained
forces response of building will be known in case of moments.
By considering each critical moment of each force design of
structural element is carried out and compared.
Key Words: Earthquake, Tsunami forces, gravity forces,
Inundation depths, coastal depths.
1. INTRODUCTION
Earthquake is an endogenous natural disaster, which occurs
suddenly without any warning. Depending upon the
magnitude and intensity, bulk of devastation takes place
with a short duration of time. The vast destruction of
engineering systems and facilities during the past
earthquakes has exposed serious deficiencies in the common
design and construction practices. These disasters have
created a new responsiveness about the disaster awareness
and easing plans. Tsunami resistant analyses are complex in
nature as the motion is transient and the force functions are
time dependent. Though there are no well established design
procedures, FEMA CCM and draft code of Bureau of Indian
Standards provide some guidelines to calculate tsunami
loads act on coastal structures. A review report by Harry Yeh
etal (2005) suggested that tsunami loads exerted on
structures can be obtained in terms of hydrodynamic, surge
and impact forces for given depth of inundation and the
velocity of approaching tsunami. Nearly 90% of all the
earthquakes due to tectonic events, primarily movement on
faults and secondly volcanism. Elastic rebound theory gives
the physics behind earthquake activities.
1.1. Physics of earthquake and tsunami’s
Tsunamis are series of sea waves of extremely long wave
length and long period generated when seafloor suddenly
lifts up almost the entire water column vertically upwards.
As the tsunami crosses deep ocean ,its wave length from
crest to crest may be a few hundred kilometres but its height
will only a few centimetres .In deep oceans ,these waves will
reach speeds exceeding 970km/hour. When tsunami enters
the coastal lines, the velocity of its waves reduces and the
wave height increases, sometimes to a height of 30m, and
strike the coast with disturbing force. The other features of
tsunami which influence the size of tsunami are the
shoreline, bathymetric formation, the velocity of sea floor
deformation and the water depth near the source of
earthquake. Tsunamis are characterized as shallow water
waves and are different from wind generated waves .A
tsunami can have a period in the range of ten minutes to two
hours and a wave length in excess of 500km. The speed of
shallow water wave is equal to the square root of the
product of acceleration due to gravity and the depth of
water. The rate at which a wave loses its energy is increased
proportional to its wave length. Hence tsunamis travel in
deep waters with high speeds and travel great transoceanic
distances with limited energy loss. Near the coast, as the
depth of water decreases the speed of tsunami diminishes.
However as the change in total energy remains constant, the
speed of tsunami decreases as it enters shallower water and
the height of the wave grows. Because of Dzshoaling effectdz, a
tsunami that was unnoticeable in deep water may grow to be
several meters in height. When a tsunami finally reaches the
shore, it appears as rapidly rising and falling tide, a series of
breaking waves. An earthquake occurs when the pressure
along a fault becomes stronger than the pressure holding the
rocks mutually. Then the rocks on either side of the fault
suddenly split apart, sometimes at supersonic speeds. The
two sides of the fault slide past one another, releasing the
pent-up pressure. Energy from this taking apart radiates
outward in all directions, including towards the surface,
where it is felt as an earthquake.
1.2. Mathematical model:
In this paper, school building is chosen for the analysis and
the tsunami forces, earthquake forces and gravity forces
imparted on these structures are worked out of different