EARTQUAKE RESISTANT BUILDINGS.pptx

INTRODUCTION
Some centuries back, landmark structures used to have:
 Heavy masonry
Strong bracings
Large foundations
The Todaiji Temple in Japan has log house construction
that has resisted earthquakes thousands of years (most number any structure has survived).
As need for taller buildings grew, advanced innovative devices
were introduced in structures.

EARTHQUAKE
 They are natural disasters of a generally unpredictable nature.
 It is the shaking of the earth due to the movement of earth’s
crust.
Terms:
Hypocenter
Epicentre
Focal Depth
Epicentral Distance

• Earthquake travels as seismic waves in all
directions through the Earth’s layers.
• These waves are of two types - body waves and
surface waves.
•Body ways- Primary and Secondary
waves.
•Surface waves-Love waves &Rayleigh
waves
•P-waves :- extension and compression
•S-waves:-oscillate at right angle
• Love-waves:- similar to s-waves with no
vertical component
• Rayleigh waves:- oscillate in elliptical path in the
vertical plane
How the ground shakes?

IMPROVING EARTHQUAKE RESISTANCE OF
MINOR BUILDINGS
Size of building
“simpler the plan better the
performance”
Construction material
“R.C.C. preferable than P.C.C.”

IMPROVING EARTHQUAKE RESISRANCE OF
MINOR BUILDINGS
“Strong-Column , Weak-Beam”
“Horizontal Band Necessary
throughout the mesonary ”
Latur Earthqukae Incident

CONVENTIONAL METHODS
(a) (b) (c)
(a) bracings in columns of open ground storey, (b) Providing R.C. shear wall and (c)
Providing brick infills between columns.
The concept is to strengthen the building.
Have stiffness and inelastic deformation
capacity.

 The bracing systems are necessary for structures that are
subjected to lateral loads due to earthquake, wind, etc.
 They help in minimizing the lateral deflection of the
structure.
 We can say that the beams and columns of the framed
structure carry vertical loads while the bracing system
carries the lateral loads.
Bracing System

 Vetically oriented wide beams
 It carries sesmic loads down to
the bottom of foundation
 Provides large strength
and stiffness to buildings.
 Thickness generally varies from
150 mm to 450 mm in high rise
buildings.
Shearwall

 Infill Masonry Walls are designed
to perform architectural functions
and there is a general agreement
among researchers that infill
frames have greater stiffness as
compared to frames without infill
walls.
 The presence of the infill walls
increases the lateral stiffness
considerably.
 Due to the change in stiffness
and mass of the structural system,
the dynamic characteristics
change as well.
Brick Infills

ADVANCED METHODS
Basic approach is to reduce the earthquake
generated forces acting upon the building;
rather than strengthening it.
Two main techniques:
Base isolation
Energy dissipation devices

BASE ISOLATION DEVICES
Supported by a series of bearing pads which are placed
between the building and the building's foundation.
In case of an earthquake:
Fixed base building deform
and are damaged.
Base isolated building rocks
back and forth like a boat.
Shaking is reduced by as
much as 5 times.

THE BUILDINGS WITH BASE ISOLATION(INDIA)
 In India, base isolation
technique was first
demonstrated after 1993 Killari
earthquake. Two single storey
building were built with rubber
base isolators resting on hard
ground.
 The four storey bhuj hospital
building was built with base
isolation technique after 2001 bhuj
earthquake.

ENERGY DISSIPATION DEVICES/
SEISMIC DAMPERS
Special devices introduced in building absorb the energy
produced by seismic waves.
•Viscous Dampers
utilized the forced
movement of fluids
within the damper.
•Friction Dampers these
utilize frictional forces to
dissipate energy.
•Metallic Dampers
utilize the deformation
of metal elements within
the damper.

THE BUILDINGS WITH ENERGY DAMPERS
1. Shanghai Tower
2. Ping An Finance Center
3. Taipei 101
4. Shanghai World Financial Center
5. Petronas Twin Towers 1 & 2
6. 432 Park Avenue
7. Princess Tower
8. 23 Marina
9. Almas Tower

IS CODES FOR EARTHQUAKE RESISTANT
DESIGN
IS 1893 (Part 1), 2002, Indian Standard Criteria For Earthquake
Resistant Design of Structures (5th revision).
IS 4326, 1993, Indian Standard Code of Practice for Earthquake
Resistant Design and Construction of Buildings (2nd revision).
IS 13827, 1993, Indian Standard Guidelines for Improving
Earthquake Resistant of Earthen Buildings.
IS 13828, 1993, Indian Standard Guidelines for Improving
Earthquake Resistant of Low Strength Masonry Buildings.
IS 13920, 1993, Indian Standard Code of Practice for Ductile
Detailing of Reinforced Concrete Structures Subjected to
Seismic Forces.

SUGGESTIONS
 Avoid weak column and strong beam design.
 Provide thick slab which will help as a rigid
diaphragm.
 Provide shear walls in a symmetrical fashion.
 Increase in the transverse (Shear) reinforcement.
 Horizontal lintel band should be provided.
 Revision/ updation of building code of INDIA .
 The building must be regular and symmetrical in
shape.

CONCLUSION
WE ARE HERE ONLY TO PROVIDE
SAFETY TO PUBLIC TO LEAD THEIR LIFE
HAPPILY.

REFERENCES
[1]. Morris, Neil; Earthquakes; Crabtree Publishing Company; 1998.
[2]. Mazza and Vulcano; Base-isolation techniques for the seismic protection of RC
framed structures subjected to near-fault ground motions; Paper No. 2935; 13th
World Conference on Earthquake Engineering at Vancouver, B.C., Canada; August
1-6, 2004.
[3]. Kelly, Skinner and Heine; Mechanisms of energy absorption in special devices for
use in earthquake resistant structures; Bulletin of N.Z. Society for Earthquake
Engineering, Vol. 5 No. 3, September 1997.
[4]. Seismic Protection with Fluid Viscous Dampers for the Torre Mayor, a 57-Story
Office Tower in Mexico City, Mexico; Publisher: Taylor Devices, Inc.;Date: 2011-
02-18.
[5]. Kourakis, Ioannis; Structural systems and tuned mass dampers of super-tall
buildings: case study of Taipei 101; Publisher: Massachusetts Institute of
Technology; 2007.
[6]. Farhat, Guenneau and Enoch, Flexural waves on a thin elastic plate are smoothly
bent around an obstacle ("E") surrounded by a metamaterial cloak, Volume 103,
Issue 2, DOI 10 July 2009.

EARTQUAKE RESISTANT BUILDINGS.pptx

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