SBST – Core elective: Earthquake Resistant Construction

Semester VI

Chandra Bhakuni -0594

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

Movement of Body

Earth diameter — 12,742 km

Basics of Earthquakes

Plate Tectonics - a theory -

Basics of Earthquakes

Plate Tectonics

wikipedia

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 EarthquakesSeismic HazardGlobal Seismic Hazard Assessment Program (GSHAP) - 1992

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

Next Class

• History of earthquakes and recording

• Assignment

Assignment

Explore one interesting point in the history of earthquakes

Find the oldest eventOne page only

Submit next week