The document discusses the mechanisms, causes, and effects of earthquakes, emphasizing structural vulnerability and building design considerations for earthquake resistance. It outlines the significance of life safety, property loss, and loss of function during an earthquake, along with mitigation measures for non-structural damages. Recommendations include proper building configuration, reinforced structures, and safety practices in construction to minimize risks associated with earthquakes.

1. An academic purpose compilation by
Prof. Bhasker V. Bhatt
Research scholar, Town planner & Civil Engineer
www.bvbhatt.com
A talk at SSASIT, Surat
Date: 27 March 2018

2. Earthquake

3. What is an Earthquake?
A Vibrations produced in the earth’s crust
when rock’s elastic strain has ruptured and
rebounded

4. What causes an earthquake?
Earthquakes are usually caused by sudden
movement on faults

5. What causes an earthquake?
A sudden release of energy accumulated in deformed
rocks causing the ground to tremble or shake.
Causes rupturing or brittle failure of crustal rocks.
Energy is released.
Movement of fault blocks takes place along a
fault plane.

6. After energy is released, friction between the adjacent fault
blocks prevents further movement. Stress resumes and
builds up again.
Friction between the blocks is overcome. Another earthquake
occurs.

7. Gujarat Earthquake
Concrete Building

8. Mexico Earthquake
Apartment Building

9. Soft-story Collapse

10. Gujarat EQ

11. Mexico Earthquake
School Building

12. Gujarat EQ
Large blocks piled up using weak bond

13. Gujarat EQ
Many casualties occurred in stone masonry
buildings

14. Gujarat EQ
Strong Structure – Weak Joint with masonry

15. Gujarat EQ
Soft story

16. Liquefaction
Nigata, Japan

17. Our Earth is Alive

18. Plate Tectonics

19. What is Mechanism of Earthquake ?

20. Different Plates around the World

21. Earthquake Occurrence

22. Himalayan Mountains

23. Earthquake

24. Seismic Waves

25. Measuring Earthquakes

26. Site Effect
The shape, amplitude, and the duration of a seismic movement
are affected, among other things, by its magnitude, the
distance to the hypocenter, and the local site conditions

27. Buildings Configuration Problem

28. Irregular Shape

29. Torsion

30. Overturning
Building Seldom Overturn-
They fall apart or pancake

31. Soft-story Collapse Mechanism

32. Ductility

33. Lateral Force Resisting
Systems

34. Considerations in
Building Layout
(plan)
and Configuration

35. Building Configuration
2
3
2
1 1
3
Symmetrical buildings in plan
and elevation are better than
asymmetrical ones.

36. Irregularity and Seismic Joints

37. Asymmetry (false symmetry) due to the location of
structural elements

38. Unsuitable plan Suitable plan
In order to make unsuitable building plans seismically
acceptable, they need to be divided into a number of
rectangular or symmetrical units.
Building Configuration
Pounding Effect

39. Building Configuration
contd....
The same principle can be applied
to the elevations of the buildings

40. b
h
h
b
Height of the building should be less than 3b
Building Configuration
contd....

41. Ideal Earthquake Resistant Building
 Small mass
 Low Height-to-base ratio
 Low center of mass relative to the ground
 Balanced lateral resistance
 Direct load paths
 Symmetrical Plan
 Uniform section and elevation
 Uniform floor heights, and
 Maximum rotational resistance
 Short spans

42. Building
Configuration
Do and Don’t do

43. Abrupt stiffness change in
elevation due to infills
Increase of Ground Floor stiffness
and strength
or

44. Asymmetry
of building
in Plan
Seismic Joints
Or
Strengthening
of Connection

45. Abrupt
Stiffness
change in
building in
Plan
Seismic Joints

46. No Yes
Interaction of Structural Elements of
Different Stiffness
Seismic Joint
Proper Design OR
Strengthening of Flexible Element

47. Significant difference between
stiffness in x and y Balanced stiffness in x and y
Asymmetric arrangement of Vertical
element (Torsional Vibration)
symmetric arrangement of
Vertical element
No Yes

48. Small contribution of Shear wall in
Torsional resistance
Increase of Torsional resistance
Incorrectly supported columns Uniform Column
No Yes

49. Unclear Frame Behavior Good Frame Behavior
in x and y
Strong beam-weak Column
(column Failure mechanism)
Weak (comparatively) beam-strong
Column (Beam Failure mechanism)
No Yes

50. Stitch at L-junctions
and T-junctions should
be designed to mitigate
the problem
Masonry Buildings

51. Masonry Buildings
contd.….
Horizontal band at sill, lintel and eve level should be
designed for out of plane bending

52. Masonry Buildings
contd.….
Stitch and band give more integrity to the building elements
and protect the building from corner opening and out of
plane failure

53. Masonry Buildings
contd.….
Vertical bars at corners T-joints and
around the openings should be designed
for tensile stress developed

54. RC Buildings
Brittle failure of RC building

55. RC Buildings
contd…..
Failure of building at beam column
joints
Joint Reinforcing
Unreinforced beam-column joints may not be able to
develop the strength of the connected members, and this can
lead to sudden brittle failure of the joint

56. Damage at Joint and Column

57. RC Buildings
contd…..
What is our practice?

58. RC Buildings
contd…..
Joint Reinforcing...

59. RC Buildings
contd…..
Failure at cold Joint

60. RC Buildings
contd…..
What we are constructing?
Cold joint...

61. RC Buildings
contd…..
Cold joint...
Shear key and rough surface give better performance

62. RC Buildings
contd…..
Column tie spacing and tie hooks
Can only
longitudinal bars
save the column?

63. RC Buildings
contd…..
Column tie spacing and tie hooks….
Comparison of damage of two columns

64. RC Buildings
contd…..
Column tie spacing and tie hooks….

65. RC Buildings
contd…..
Short column effect…...

66. Short column effect…...
RC Buildings
contd…..

67. Short column effect…...
RC Buildings
contd…..

68. RC Buildings
contd…..
Column-bar splices

69. Non structural Damage and
its Mitigation

71. Broken Glass
in Kitchen

72. Room
In Bed Rooms
Furniture overturned throwing outside
the contents

73. Bureau Toppled

74. Office
In office
Furniture, file cabinets overturned

75. Shops
In shops and departmental stores
Many liquor and bottles broken

76. Non-structural damage
In Book Store and
Libraries

77. Non-structural damage
Shattered glasses

78. Water Heaters Tip Easily
During Earthquakes

79. Significance: Life Safety
 If a ten-rupees
flowerpot , not
fastened well to the
building, falls on
someone’s head, it
can be a killer!

80. Significance: Property Loss
 Very important in case of
commercial and Institutional
buildings
 Property losses in 25
commercial buildings due to the
1971 San Fernando earthquake:
 Structural damage 3%
 Electrical and mechanical 7%
 Exterior finishes 34%
 interior finishes 56%.

81. Significance: Loss of function
 Critical facility
 Hospital
 Telecommunication etc.

82. Mitigation Measures :
Removal
 A hazardous material that could be spilled,
could be stored perfectly well outside the
premises
 One solution would be stronger fastening or
the use of stronger supports,
 But the most effective solution would be
removal and replacement

83.  A very heavy
object on top of a
shelf could fall and
seriously injure
someone
 If it is relocated to
a floor-level shelf
it would not
represent any
danger to human
lives or to property. Store large, heavy or fragile objects on
lower shelves or in low closed cabinets
Relocation

84.  Anchorage of Battery Rack+ Anchorage of Book
shelve SOURCE: EERI
Anchorage

85. Anchorage
SOURCE: PAHO/WHO

86. Restricted Mobilization
 It does not matter if
the cylinders shift as
long as they do not fall
and break their valves.
Sometimes back-up
power generators are
mounted on springs to
reduce the noise and
vibrations when they
are working, but these
springs would amplify
ground motion.

87. Flexible Couplings
The use of flexible piping in
critical areas such as
between buildings and
equipment helps to prevent
breakage
PAHO/WHO

88. Supports
Damage to ceilings

89. Supports

90. Substitution
 A heavy tiled roof does not only make the roof of a
building heavy, it is also more susceptible to
earthquake shaking. The individual tiles tend to come
off, creating a hazard for people and for objects.
 One solution would be to change it for a lighter, safer
roofing material.

91. Modification
 Rolls of transparent adhesive plastic
may be used to cover the inside
surfaces and prevent them from
shattering and threatening those
inside.

92. Reinforcement
 Useful for
 Unreinforced infill wall
 Chimney may be strengthened

93. Redundancy
 Redundancy or duplication of items is
advisable.
 An emergency response plan requiring
storage of emergency supplies is a good
idea.
 It is possible/necessary to store extra
quantities of certain products, providing a
certain level of independence from external
supply which could be interrupted in the
case of earthquakes.

94. Limit Sliding & Rocking Movements

95. Restraints and fasteners
for smaller equipment

96. Simple improvement can save
life and property

97. Nonstructural Vulnerability Reduction

99. BHASKER BHATT
Researchh scholar & Town Planner, Civil Engineer
C:+91-98258-35364 E: er.bhasker@gmail.com
www.bvbhatt.com
Promote & Practice Safe
Construction…
 Thanks…