This document discusses earthquake resistant structures and techniques. It covers topics such as plate tectonics, earthquake hazards, classification of earthquakes, principles of earthquake-resistant design, Indian seismic codes, shear walls, case studies of past earthquakes, and techniques like base isolation, energy dissipation devices, and keeping buildings uplifted. The overall aim is to educate on designing and building structures that can better withstand seismic activities and reduce damage through engineering strategies.
2. CONTENTS
INTRODUCTION
PLATE TECTONICS
HAZARDS DUE TO EARTHQUAKE
CLASSIFICATION OF EARTH QUAKES
WHAT IS EARTH QUAKE ENGINEERING ?
PRINCIPLE OF EARTH QUAKE RESISTANT DESIGN
EARTHQUAKE RESISTANT STRUCTURES
RULES FOR BUILDING DESIGN
INDIAN SEISMIC CODES
SEISMIC EFFECTS ON STRUCTURES
SHEAR WALL
CASE STUDY ON JAPAN EARTHQUAKE
EARTHQUAKE RESISTING STRUCTURE TECHNIQUES
REFERENCES
CONCLUSION
2
3. PLATE TECTONICS
Earth’s rigid outer shell is broken in to gigantic
slacks of rock called oceanic and continental plates
.
3
4. HAZARDS DUE TO EARTHQUAKE
Liquefaction of Soils
Ground Shaking
Surface Rupture
Landslides
Lateral Spreading
Shear Failure of Foundation
Settlements of Structures
Failure of Retaining Wall
Tsunamis 4
5. CLASSIFICATION OF EARTH QUAKE
Slight : Magnitude up to 4.9 on
the Richter Scale
Moderate : Magnitude 5.0 to 6.9
Severe : Magnitude 7.0 to 7.9
Very Severe : Magnitude 8.0 and above
5
6. WHAT IS EARTHQUAKE ENGINEERING?
Earthquake engineers are
concerned with creating
earthquakes resistant designs and
construction techniques to build of
all kinds of bridges, roads and
buildings.
Earthquake engineers are faced with
many uncertainties and must be
smart in their decisions in
developing safe solutions to
challenging problems. They rely
on state-of-the-art technology,
materials science, laboratory
testing and field monitoring. 6
7. PRINCIPLE OF EARTHQUAKE-
RESISTANT DESIGN
The building shall with stand with almost no
damage to moderate earth quake which have
probability of occurring several times during life of a
building.
The building shall not collapse or harm human lives
during severe earth quake motions, which have a
probability of occurring less than once during the
life of the building.
7
11. RULES FOR BUILDING DESIGN
The configuration of the building (Plan and
elevation)should be as simple as possible.
The foundation should generally be based on hard
and uniform ground.
The members resisting horizontal forces should be
arranged so that torsional deformation is
not produced.
The frame of the building structure should have
adequate ductility in addition to required strength.
11
12. INDIAN SEISMIC CODES
IS 1893-2002, Indian Standard Criteria for Earthquake
Resistant Design of Structures (5thRevision)
IS 4326-1993, Indian Standard Code of Practice for
Earthquake Resistant Design and Construction of Buildings
(2ndRevision)
IS 13827-1993, Indian Standard Guidelines for Improving
Earthquake Resistance of Low Strength Masonry Buildings
IS 13920-1993, Indian Standard Code of Practice for Ductile
Detailing of Reinforced Concrete Structures Subjected to
Seismic Forces
IS 13935-1993, Indian Standard Guidelines for Repair and
Seismic Strengthening of Buildings 12
14. SHEAR WALL
A Wall topples down easily if pushed
horizontally at the top in a direction
perpendicular to its plane. this is
out of plane failure.
How ever, a wall offers much greater
resistance if pushed along its length.
this is called in-plane resistance.
Such a wall carrying horizontal loads in its own
plane, is known as a “Shear Wall”.
14
15. ADVANTAGES OF SHEAR WALL
Efficient in terms of :
Cost
Effectiveness
Construction
Helps in minimizing the effect on Non-structural
elements . E.g. glass , windows.
It is said that :-
“we cannot afford to build concrete
buildings meant to resist severe earthquakes
without Shear Wall.” 15
16. CASE STUDY ON JAPAN EARTHQUAKE
The major earthquake that struck the Pacific Coast
of East Japan on March 11, 2011 claimed the lives
of over 15,000 people and destroyed or partially
damaged many buildings.
More than 90% of the fatalities and most of the
structural damage, however, were caused by the
massive tsunami that followed.
Magnitude of earthquake was 9.0.
Sendai MT Building remained undamaged which
was constructed using seismic isolation technique.
16
18. EARTH QUAKE RESISTING
STRUCTURE TECHNIQUES
Base Isolation Method
Energy Dissipation Device
-(Seismic Dampers)
Keeping Building Up Thrust
18
19. BASE ISOLATION
Introduces flexibility
to the structures.
Building is rested on
flexible pads.
When earthquake strikes the
building does not move.
It is suitable for hard soil only. 19
20. SPHERICAL SLIDING BASE ISOLATION
The building is supported by bearing pads that have
a curved surface and low friction.
Since the bearings have a curved surface, the
building slides both horizontally and vertically. 20
21. ENERGY DISSIPATION DEVICE – SEISMIC
DAMPERS
These are used in the place of structural elements
such as diagonal braces .
Acts like the hydraulic shock absorbers in cars.
When seismic energy is transmitted through them
dampers absorb part of it, and thus damp the
motion of the building. 21
22. TYPE OF SEISMIC DAMPERS
Viscous Dampers
(energy is absorbed by silicone-based fluid
passing between piston cylinder arrangement)
Friction Dampers
(energy is absorbed by surfaces with friction
between them rubbing against each other)
Yielding Dampers
(energy is absorbed by metallic components that
yield)
Visco-elastic Dampers
(energy is absorbed by utilizing the controlled
shearing of solids). 22
23. KEEPING BUILDING UP THRUST
This technique is discovered by Japan.
It has found to be survived even in extreme
earthquakes.
23
24. CONCEPT OF
KEEPING BUILDING UP THRUST
When the quake strikes, the system dissipates
energy in the building cores and exteriors.
The frames are free to rock up and down within
fittings fixed at their bases 24
25. CONCLUSION
Design the structure to resist the loads for safety
against Earthquakes.
Base isolation can also be used for retrofitting of
structure
Construct symmetrical structure to avoid torsion.
No structure on the planet can be constructed
100% earthquake proof , only its resistance to
earthquake can be increased.
25
26. REFERENCES
Earthquake resistant design of structure of
structures by Pankaj Agarwal and Manish
Shrikhande.
http://web-japan.org/trends/11_sci-
tech/sci110728.html
26