EASTERN JAPAN GREAT EARTHQUAKE DISASTER

Byju V

M2 Structural Engineering

Date and time Friday, March 11, 201102:46:23 PM - Local Time

Epicentre 38.322oN and 142.369oE

Magnitude 9

Intensity Up to VII

Peak ground acceleration

2g to 0.34 g

Characteristics

2

Peak ground acceleration

2g to 0.34 g

Foreshocks and aftershocks

About 50 (5 of magnitude >7)

Energy released Earthquake 1.9 0.5 X 1017 J

Total including tsunami 3.9 X 1022 J

Velocity of tsunami wave

700 kilometers per hour

Characteristics

3

Ring of fire

Plate movement

Pacific plate slipped beneath Eurasian plateIt was moving a few cm every year

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Plate movement

5

Epicentre

6

Intensity of earthquake7

Tsunami following the quake8

Impacts

• Humanitarian

» 13,392 deaths

» 15,133 missing

» 4896 injured

» 3,35,000 refugees

• Buildings

» 59,806 destroyed

» 12,728 damaged

» More in tsunami than earthquake

9

Impacts

• Infrastructure

» Power, nuclear, railway, air port, ports

• Economic

» Total loss $ 171 to 183 billion

» Total cost of recovery $ 122 billion

10

Nuclear crisis• Crisis at Fukushima

• Level 7 nuclear event

• What happened?

• The height of sea wall was insufficient

• Power system was poorly designed

• IAEA norms – Design to consider eventshaving probability of 1 in 10,000 years

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Damage to structuresPrestressed Concrete Institute (PCI) report

• No widespread structural damage

• Damages mainly from tsunami, not shaking

• Major damages due to quake suffered by oldbuildings built before code revisions.

• Several changes to building codes in last 40years, after 1968 earthquake

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Code revisions Review procedure for existing buildings for seismic

safety.

Reduced the spacing of steel ties in columns to 100 mm

Ultimate strength design for shear of beams andcolumns

More stringent requirements for shear reinforcement

Two phase design

i. 0.08 g to 0.1 g (can occur several times)

ii. 0.3 g to 0.4 g (Can occur once in the lifetime ofbuilding)

Performance based seismic design introduced in 2000

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Design flow chart

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Preparedness Many measures by Japan after 1995 earthquake

World’s first earthquake early warning system

Rapid and systematic and calm reporting bymedia

Heavy investment in educating public aboutdisaster management

One of the most stringent constructionstandards

The highest disaster risk aware population

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• Very old timber houses are generally collapsed.• Damage is generally limited to roof with tiles.• Damage to timber houses built on a soft ground or

nearby creeks or rivers.

Damages to timber buildings

16

Damages to masonry buildings

o Damage is generally limited to roof with tiles.o As the number of masonry buildings are few, no

major collapses were observed17

Damages to RC buildings

Complete collapse of a few buildings built before code revisions 18

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Tilting of RC building due to liquefaction

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Damaged Nakaminato Thermal Power Plant due to heavy liquefaction

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Shiogama Municipal No. 2 Junior High School retrofitted using an external precast concrete frame braced with tension ties

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1. Okada Norio et. al. (2011), “The 2011 Eastern Japan Great Earthquake Disaster: Overview and Comments”, Int. J. Disaster Risk Sci., 2 (1): 34–42

2. Richard Sause et. al, “Preview of PCI’s Japan earthquake Reconnaissance Team Report”, www.pci.org

3. Ömer Aydan and HisatakaTano (2011), Shaking – induced damage to buildings by M 9.0 East Japan mega earthquake on March 11, 2011

4. Ömer Aydan and HisatakaTano (2011), Liquifaction-induced damage to buildings by M 9.0 East Japan mega earthquake on March 11, 2011

5. www.sefindia.org6. www.jsce-int.org

References

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