View
10
Download
0
Category
Preview:
DESCRIPTION
ppt
Citation preview
*CC Chang / HKUSTEarthquake Response Chapter 6
Some QuestionsEarthquake: what do you know?How big can it get? What can we do about it?
Earthquake as We Speak
Largest earthquakes(Since 1900)
LocationDate UTCMagnitude1.Chile1960 05 229.52.Prince William Sound, Alaska1964 03 289.23.Off the West Coast of Northern Sumatra2004 12 269.14.Sendai2011 03 119.05.Kamchatka1952 11 049.06.Offshore Maule, Chile2010 02 278.87.Off the Coast of Ecuador1906 01 318.88.Rat Islands, Alaska1965 02 048.79.Northern Sumatra, Indonesia2005 03 288.610.Assam - Tibet1950 08 158.611.Andreanof Islands, Alaska1957 03 098.6
Largest earthquakes(2013)
Most destructive known earthquakes on record in the world
DateLocationDeathsMagnitudeCommentsJanuary 23, 1556China, Shansi830,000 ~ 8January 12, 2010Haiti316,0007.0July 27, 1976China, Tangshan242,769 8.0Estimated death toll as high as 655,000August 9, 1138Syria, Aleppo230,000December 26, 2004Indonesia, Sumatra227,898 9.1Deaths from earthquake and tsunamiDecember 22, 856+Iran, Damghan200,000December 16, 1920China, Ningxia200,0007.8Major fractures, landslides.March 23, 893+Iran, Ardabil150,000September 1, 1923Japan, Kwanto142,8007.9Great Tokyo fireMay 12, 2008China, Sichuan87,5877.9
Earthquakehttp://environment.nationalgeographic.com/environment/natural-disasters/earthquake-profile.html
Seismic Damage of InfrastructureDirect EffectsGround failures; Surface rupture; Soil vibration; Ground liquefaction; Others Structural vibration and damageIndirect EffectsTsunamisSeichesLandslidesFloodsFires
Ground failures/Surface ruptureNormal fault. Scarp near Beni Rached1980 El Asnam Earthquake
Soil vibration; Ground liquefaction
Soil vibration; Ground liquefaction
Soil vibration; Ground liquefactionChi-Chi Earthquake 1999
Soil vibration; Ground liquefactionDisplacement and tilting of houses due to soil liquefaction in the Turnagain Height area of Anchorage during the 1964 Alaska Earthquake
Others New mountain created during Chi-Chi Earthquake 1999
Others Chi-Chi Earthquake 1999
Structural Vibration and DamageFailure of the unreinforced masonry walls of a five-story reinforced concrete building during the 1972 Managua Earthquake
Structural Vibration and DamageImperial Valley County, California. Collapse of a steel tank during the 1979 Imperial Valley Earthquake.
Structural Vibration and DamageFailure of a building at central Kobe after 1995 Kobe earthquake [4]
Structural Vibration and DamageFailure of a building at central Kobe after 1995 Kobe earthquake
Structural Vibration and Damage
Structural Vibration and Damage
Tsunamishttp://www.eri.u-tokyo.ac.jp/topics/kiihantouoki2004/index-e.html
Tsunamis
Fires1995 Kobe earthquake
FiresChi-Chi Earthquake 1999
Estimated economic losses of some recent earthquakes Hong Kong (2012) revenues: $360 billion HKD or $46 billion USD Stonecutters Bridge costs around 0.5 billion USD
LocationDate UTCMagnitudeEstimated economic loss (in billion US dollars)Loma Prieta, California1989 7.17Northridge, California1994 6.713-20 [1]Kobe, Japan1995 6.995-147 (repair only [2])Chi-Chi, Taiwan19997.67.8
Philosophy of Seismic Resistant Design for StructuresMinor earthquake: prevent non-structural damageModerate earthquake: prevent structural damage and minimize non-structural damageMajor earthquake: avoid collapse to save lives
How to design structures under earthquake?EQIssues: Different EQs different characteristics Structural modeling and performance
How to design structures under earthquake?
Generalized Coordinates?
Earthquake Response SpectraEOMis a function of
Response SpectraUnder a specific earthquake
Response SpectraMaximum responses
Response SpectraDisplacement, velocity and acceleration response spectra for a SDOF system under the NS component of the 1940 El Centro earthquake ground excitation ( )
Pseudo-Response SpectraDisplacement, pseudo-velocity and pseudo-acceleration response spectra for a SDOF system under the NS component of the 1940 El Centro earthquake ground excitation ( )Pseudo-velocityPseudo-acceleration
Actual and PseudoResponse Spectra
DVA Response Spectrum
Equivalent Static Force,Shear and MomentEquivalent Static ForceShear ForceMoment
Example E4.1A SDOF Frame under 1940 El Centro EQ Estimate the maximum base shear forces and the maximum bending moment for the building frame under the 1940 El Centro earthquake excitation. The damping ratio of the frame can be assumed to be 2%.
Example E4.1A SDOF Frame under 1940 El Centro EQThe natural period of the building frame is Stiffness
Example E4.1A SDOF Frame under 1940 El Centro EQBase shear for each columnTotal overturning moment
DVA Response Spectrum: Discussion
Elastic Design SpectrumThe DVA spectrum depends on the Earthquake used
Elastic Design Spectrum
Elastic Design Spectrum
Constructing Elastic Design Spectrum
A, gD, me
Constructing Elastic Design Spectrum
Example A SDOF Frame under Design Spectrum Estimate the maximum base shear forces and the maximum bending moment for the building frame under the elastic design spectrum obtained previously. The damping ratio of the frame is assumed to be 3%.
ExampleA SDOF Frame under Design Spectrum The natural period of the building frame is 1.4gBase shear for each columnTotal overturning moment
Eurocode 8
***********************************************
Recommended