1994 Northridge Earthquake

1
1994 Northridge Earthquake

• LAUREN ARTHOFER
• LAURA CAIN

2
Outline

• Quick Facts
• Geophysical Aspects
• Affect of Earthquake
• Experiment One Data
• Experiment Two Data
• Conclusion
• References

3
Quick Facts

• January 17, 1994
• Northridge
• Magnitude
• 6.7(Richter)
• San Fernando
• Valley
• Northridge/
• Pico Thrust
• Duration 15 seconds

4
Geophysical Aspects

• Pico Fault
• Blind Thrust Fault (most dangerious)
• Size (length) of fault unknown
• Depth 11.8 miles below surface
• North America and Pacific plates
• Aftershock
• Over 300
• Some above 5.0 magnitude

5
Damage

• 57 fatalities and 1500 serious injuries
• 22, 000 people left homeless
• Six bridges failed and four were seriously
  damaged
• Total Damage Approximately 15 billion

6
Experiment One
I
II
III

• Subjected three structures with different heights
  to free vibration
• Calculated the period, frequency and damping of
  the structures

7
Building One Data
8
Building Two Data
9
Building Three Data
10
Experiment One Conclusion

• From our data, we have concluded that when
  subjected to free vibration
• The shortest structure had the shortest period
  and the highest frequency
• The tallest structure had the longest period and
  the shortest frequency

11
Experiment Two

• Ran structures through the Northridge earthquake
  ground motion on the shake table
• Finding the maximum acceleration of the
  structures using the period and damping from
  experiment one

12
Building One
13
Building Two
14
Building Three
15
Northridge Earthquake Pseudo Acceleration Graph

• Shows the maximum acceleration of a buildings
  with different periods and damping.

16
Experiment Two Conclusion

• The shortest building had the largest maximum
  acceleration
• The tallest structure had the smallest
  acceleration

17
Conclusion

• Maximum acceleration of a structure in the
  Northridge Earthquake
• Caused an enormous amount of damage
• Current building codes significantly decreased
  damage
• Increased earthquake awareness and preparation

18
References

• http//www.u-s-history.com/pages/h2176.html
• http//www.vibrationdata.com/earthquake/northridge
  .htm
• http//en.wikepedia.org/wiki/1994_Northridge_Earth
  quake
• http//www.seismo.unr.edu/ftp/pub/louie/class/100/
  magnitude.html
• http//pasadena.wr.usgs.gov/office/hudnut/hudnut/n
  r_eq.html
• http//www.tfhrc.gov/pubrds/summer94/p94su26.htm
• http//pubs.usgs.gov/pp/pp1550/pp1500e/
• http//www.dis-inc.com/northrid.htm