eastern japan great earthquake disaster
TRANSCRIPT
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
4
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
11
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
12
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
13
Design flow chart
14
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
15
• 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
19
Tilting of RC building due to liquefaction
20
Damaged Nakaminato Thermal Power Plant due to heavy liquefaction
21
Shiogama Municipal No. 2 Junior High School retrofitted using an external precast concrete frame braced with tension ties
22
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
23