During the semester
• Introductions• Basics of earthquakes• History of earthquakes and damaging earthquakes• Understanding seismic exposure and loss assessment• Seismic analysis; and design and detailing (RCC and
Masonry)
Basics of Earthquakes
Plate Tectonics
http://www.abag.ca.gov/bayarea/eqmaps/fixit/ch2/sld003.htm
Basics of Earthquakes
Plate Tectonics
http://www.abag.ca.gov/bayarea/eqmaps/fixit/ch2/sld004.htm
Basics of Earthquakes
• Release of energy from earth’s crust• Type of Waves• Body Waves (P wave & S wave) • Surface Waves• Rayleigh waves
Basics of Earthquakes
India Seismic Risk Zones
Bureau of Indian standardsIS 1893 (Part 1) - 2002
http://www.iitk.ac.in/nicee/EQTips/EQTip04.pdf
Basics of Earthquakes
• Branch of Structural Dynamics
Simplified SDOF ‘equation of motion’
f(t) = ma + kt + cu
Or’
f(t) = cu + ků + mϋ
F = Shear Forcem = Massk = Stiffnessc = damping coefficienta = accelerationT = time periodU = displacement
Basics of Earthquakes
Natural Frequency, fn,
Where,fn = Natural Frequency (Hertz ) or (No. of Cycles/Second)k = Element Stiffness (N/m)m = Element Mass (kg)
Single degree of freedom (SDoF) oscillator
Radian frequency, ωn = 2 π fn
Basics of Earthquakes
History of Earthquakes
Some Big Reported events in last 10 years
2010 04 13 - Southern Qinghai, China - M 6.9 Fatalities 2,968 2010 01 12 - Haiti region - M 7.0 Fatalities 222,5702009 09 30 - Southern Sumatra, Indonesia - M 7.5 Fatalities 1,1172008 05 12 - Eastern Sichuan, China - M 7.9 Fatalities 87,5872005 10 08 - Pakistan - M 7.6 Fatalities 86,0002004 12 26 - Sumatra-Andaman Islands - M 9.1 Fatalities 227,8982003 12 26 - Southeastern Iran - M 6.6 Fatalities 31,0002001 01 26 - Gujarat, India - M 7.6 Fatalities 20,023
http://earthquake.usgs.gov/earthquakes/world/historical.php