This document discusses earthquake resistant design of structures. It begins by defining earthquakes and their causes, then describes the inner structure of the Earth. It discusses tectonic plate movement, earthquake types, waves produced by earthquakes, measuring earthquakes, and seismic zoning in India. The document covers effects of earthquakes on structures, how buildings twist in quakes, seismic design philosophy, ductile design for performance, Indian seismic codes, and techniques columns and joints use to resist quakes. It addresses vulnerabilities of open-ground storeys and short columns, and concludes with ways to reduce earthquake effects on buildings.

1. Earthquake Resistant
Design of Structures
N.Venkata Ramana
AMIE,M Tech, Ph.D
Associate Professor
Civil Engineering Department
UBDT CE, DAVANGERE
KARNATAKA-STATE
PIN 585105

2. •EARTHQUAKE
•Earthquake is vibration of earth surface by waves emerging from
the source of disturbance in the earth by virtue of release of
energy in the earths crest
Earthquake
Tectonic
Volcanic
•Tectonic earthquakes are associated with the sudden dislocation of
large rock masses along the geological fault
•Volcanic earthquakes are those associated with volcanic eruption and
have limited field
•When earthquake occurs beneath the sea, the water above the
deformed area gets displaced form equilibrium position.
Series of waves or wave train, called earthquake generated
tsunami waves are formed as huge water columns which
can have vertical run-up height of 10m,20m and even 30m,
offshore above sea level

4. Inner Core (radius)=1290Km
Nickel and Iron
Temp=2500 c,
Pressure=4 million atm.
Density=13.5 gm/cc
Outer Core (Thickness)=2200km
Liquid from
Mantle (Thickness)=2900km
Ability to flow
Crust (Thickness)=5 to 40Km
Basalt and Granite
Temp=25 c,
Pressure=1 atm.
Density=1.5 gm/cc

5. 1.Convection currents develop in the viscous mantle
because of prevailing high temperature
And pressure gradient between crust and the core.
2.The energy for circulation is derived from the heat produced form the
incessant decay of radioactive elements in the rocks throughout the earths
interior

6. •Tectonic Plates
•Mountains
•Rifts
•Convergent, Divergent and
Transform
•Centimeter per year

7. 1.The Earthquake
2.Fault: A crack in the rocks where
movement take place
3.Slip
4.Energy released during Bhuj (2001) equthquake
is about 400 times more that released
by the 1945 atom bomb dropped on
Hiroshima
5.Sudden slip at the faults causes earthquake
6.Elastic Rebound theory

8. 1.Inter Plate Earthquakes(1897 Assam (India))
2.Intra Plate Earthquakes (1993 Latur (India))
3.Dip Slip
4.Strike Slip

10. 1.Body waves
Primary waves(P –waves)
Secondary waves(S-waves)
2.Surface Waves
Love waves
Rayleigh waves
3.Velocity :- P>S>L>R
4.S waves don not travel through liquid
5.S waves association with Rayleigh waves
causes max damage to structure.
6.Shaking is more severe at the earths surface
than at substantial depths.

11. Measuring Instrument
1.Seismograph
Sensor
(Pendulum mass, string, magnet
and support together )
Recorder
(drum, pen and chart)
Timer
(The motor that rotates the
drum at constant speed forms the
timer)
2.Digital Instrument
3.Characterstics of Strong
Ground Motions
Displacement, velocity and
acceleration.
4.PGA (peak ground acceleration)
5.Max amplitude of horizontal
motion in the two orthogonal
directions are about same.
6.Thevertical acceleration is taken
as 0.5 to 0.6 of the horizontal
acceleration

13. 1.Terminology
Focus or Hypocenter
Epicenter
Focal depth
Epicentral distance
2.Main shock, Fore shocks & After shock
3.Magnitude
•Richter Scale (Local magnitude scale)
•Body wave magnitude, surface wave
magnitude and
wave energy magnitude
4.An increase in magnitude(M) by 1.0 implies
10 times higher waveform amplitude
and about 31 times higher energy
released
5. Most of times energy released goes into heat
and fracturing the rocks and a small fraction of
it goes into the seismic waves that travel into
large distance causing shaking of the ground en
route and hence damage to structure.

14. Intensity:
1.Qualitative measures of the actual
shaking at a location during earthquake and
it is assigned by roman capital numerals
2.Modified Mercalli Intensity (MMI) and MSK
scale (I (least perceptive) to XII (most severe)
3.Lines joining places with equal seismic
intensity called ISOSEISMALA
4.Magnitude is single value for given earth
quake but the intensity is an indicator of the
severity of shaking generated at a given
location

15. Magnitude and Intensity in Seismic Design
Gutenberg and Richter (1956)
Ml (local Magnitude)= 2/3 I0+1
I0= intensity sustained in the local epicentral area
(For using this equation, the roman numbers of intensity are replaced
with the corresponding Arabic numerals e.g.. Intensity IX with 9.0)
Modified Mercalli Intensity=((MMI))

16. 4.WHERE ARE THE SEISMIC ZONES
IN INDIA

18. 1.First seismic zone map 1962
Revised in 1967
Revised in 1970
Revised in 2002
2.Micro-zoned
3.The national seismic zone map
presents a large scale view of the
seismic zones in the country
4.Local variation in soil type and
geology cannot be represented at
that scale.
5.For important projects such as a
major dam or a nuclear power plant
the seismic hazard is evaluated
specifically for that site

19. 5.What are the seismic
effects on structures?

21. 6.HOW ARCHITECTURAL FEATURES
AFFECT
BUILDINGS DURING EARTHQUAKES

23. 7.HOW BUILDINGS TWIST DURING
EQRTHQUAKES

25. 8.What is the seismic design
philosophy for buildings?

27. 9.HOW TO MAKE BUILDINGS
DUCTILE FOR GOOD
SEISMIC PERFORMANCE

31. 11.WHAT ARE THE INDIAN SEISMIC CODES?

43. 19.How do columns in RC
buildings Resist Earthquakes

45. 20.HOW DO BEAM-COLUMN
JOINTS IN RC
BUILDINGS RESIST EARTHQUAKES?

47. 21.WHY ARE OPEN-GROUND
STORETY BUILDINGS
VULNERABLE IN EARTHQUAKES

49. 22.WHY ARE SHORT COLUMNS MORE
DAMAGED
DURING EARTHQUAKE

53. 24.HOW TO REDUCE
EARTHQUAKE EFFECTS ON
BUILDINGS.