Structural an nonstructral damage of RC structures due to earthquakes

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EARTHQUAKE STRUCTURAL DAMAGE
Dr. Ahmed Tarabia
Damage types
Structural
elements
Non structural
elements

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• 1- due to ground movements and soil changes.
• 2- Damage due to building shape or dimensions
• 3- Damage due to structural elements.
Main causes of structural damage
 Landslides
 Ground liquefaction
 Seismic sea waves (Tsunami’s)
Fault movements.
Due to ground movements and soil
changes.

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Ground Liquefaction:Niigata, Japan 1964 (Mag. – 7.5)
Ground Liquefaction:

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Faults movements
Damage due to building shape or
dimensions
• 1- Soft story failure.
• 2- Short column failure.
• 3- Torisonal failure.
• 4- Pounding ( ‫المباني‬ ‫تصادم‬ )

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Soft story failure
1- Shows a significant decrease in lateral stiffness from that immediately above.
How:
- Height of this floor is higher than the rest of floors.
- Change of section that reduce the stiffness.
- Removing of infill walls
Soft Story: one floor has less
stiffness than the adjacent
floors

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Soft story failure case
5th floor restaurant Open structure Stories above and
below have more support

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‫األدوار‬ ‫الحد‬ ‫االعمدة‬ ‫من‬ ‫مجموعة‬ ‫من‬ ‫ينتج‬ ‫القصير‬ ‫العمود‬:
1-‫يزيد‬ ‫مما‬ ‫األعمدة‬ ‫باقي‬ ‫من‬ ‫أقصر‬ ‫االعمدة‬ ‫لبعض‬ ‫الخالص‬ ‫الطول‬
‫العمود‬ ‫على‬ ‫المؤثر‬ ‫القص‬ ‫يزداد‬ ‫بالتالي‬ ‫و‬ ‫الكزازة‬ ‫من‬.
‫الكانات‬ ‫تكثيف‬ ‫و‬ ‫القص‬ ‫تسليح‬ ‫زيادة‬ ‫طريق‬ ‫عن‬ ‫ذلك‬ ‫عالج‬ ‫يتم‬.
Short Column failure
Short Column failure
Failure of short columns due to :
increasing stiffness:
-Less clear height of column.

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Short Column failure
Clear height
Torisonal failure.
The center of rigidity is not coincided with the force center

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Torisonal failure.
Torisonal failure.

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Pounding
If the distance between two buildings are very
small, they may collide with each other during
earthquake. The forces due to collision is ver
high. To prevent this damage:
• You must leave a minimum separation distance.
• Design the two building for these forces.
• Add special walls to resist this force.
Pounding failure.

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• 1- Column failure.
• 2- Beam failure.
• 3- Beam-column failure.
• 4- Shear wall failure.
Damage of structural elements
1- Column failure.
Buckling of longitudinal steel due to
large spacing of stirrups.

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1- Column failure.
Using confinement in columns
Confined with spiral stirrups
Using separate stirrups
with large spacing
1- Column failure.
Bond failure at the lap splice joint

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1- Column failure.
Bond failure :Short length of column extension in the
beam
1- Column failure.
Bond failure at the lap splice joint

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1- Column failure.
Failure of the stirrup hook.
1- Column failure.
Shear failure of column

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2- Beam failure.
Buckling of beam reinforcement
Shear failure of beam
2- Beam failure.

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splice failure of beam
2- Beam failure.
3- Beam-Column Joint failure.
• Longitudinal beam bars
not confined within
column longitudinal
bars or ties

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3- Beam-Column Joint failure.
No intermediate ties in
joint normal to outside
face of joint
3- Beam-Column Joint failure.
-No transverse reinforcement through joint
-Insufficient anchorage for hooked bars
-Widely spaced ties outside of joint
-No intermediate ties in column

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4- Shear Wall failure.
Shear failure of wall
4- Shear Wall failure.
Sliding Shear failure
of wall

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Non structural damage.
Non structural damage.

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