The 2011 Tohoku earthquake and tsunami caused widespread damage in eastern Japan. The magnitude 9.0 earthquake struck off the coast of Japan on March 11, 2011, generating massive tsunami waves up to 40 meters high. Over 15,000 people were killed or went missing, and infrastructure, buildings, and the Fukushima Daiichi nuclear power plant suffered severe impacts costing over $171 billion total. While older buildings not built to modern codes suffered structural failures, newer structures generally performed well in the earthquake shaking though many were damaged or destroyed by the tsunami waves. The disaster highlighted the need for stringent seismic design codes and public education around disaster preparedness.

1. EASTERN JAPAN GREAT
EARTHQUAKE DISASTER
Byju V
M2 Structural Engineering

2. Date and time Friday, March 11, 2011
02:46:23 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

3. 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

4. Ring of fire
Plate movement
Pacific plate slipped beneath Eurasian plate
It was moving a few cm every year
4

5. Plate movement
5

6. Epicentre
6

7. Intensity of earthquake 7

8. Tsunami following the quake 8

9. 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

10. Impacts
• Infrastructure
» Power, nuclear, railway, air port,
ports
• Economic
» Total loss $ 171 to 183 billion
» Total cost of recovery $ 122 billion
10

11. 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 events
having probability of 1 in 10,000 years
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12. Damage to structures
Prestressed Concrete Institute (PCI) report
• No widespread structural damage
• Damages mainly from tsunami, not shaking
• Major damages due to quake suffered by old
buildings built before code revisions.
• Several changes to building codes in last 40
years, after 1968 earthquake
12

13. 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 and
columns
 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 of
building)
 Performance based seismic design introduced in 2000
13

14. Design flow chart
14

15. Preparedness
 Many measures by Japan after 1995 earthquake
 World’s first earthquake early warning system
 Rapid and systematic and calm reporting by
media
 Heavy investment in educating public about
disaster management
 One of the most stringent construction
standards
 The highest disaster risk aware population
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16. • 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

17. 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 observed 17

18. Damages to RC buildings
Complete collapse of a few buildings built before
code revisions 18

19. 19

20. Tilting of RC building due to liquefaction
20

21. Damaged Nakaminato Thermal Power Plant due to heavy liquefaction
21

22. Shiogama Municipal No. 2 Junior High School retrofitted using an
external precast concrete frame braced with tension ties 22

23. 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.org
6. www.jsce-int.org
References
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