Earthquake Analysis of an Existing Structure in the Southeast Region of the United States Terri Nort

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Earthquake Analysis of an Existing Structure in
the Southeast Region of the United StatesTerri
Norton and Makola M. Abdullah, Ph.DWind Hazard
Earthquake Engineering LabFAMU-FSU College of
Engineering

• DAMAGE APPROXIMATION

• ABSTRACT
• Earthquakes can and do happen in the Southeastern
  United States. In areas where earthquakes are
  likely to occur, knowing where to build and how
  to build can be helpful in reducing property
  damage. This study involves producing a detailed
  earthquake analysis of an existing high-rise
  structure in the southeast region. The analysis
  of the structure is based on the effects of past
  earthquakes in the Eastern United States. The
  probability of structural and non-structural
  damage, caused by the buildings displacement,
  was approximated through the use of fragility
  curves. Repair costs were estimated based on the
  probability of exceeding each damage state.
  Passive control devices were used to improve the
  response of the building and reduce the extent of
  damage. The findings of this study will be used
  as a means of educating both students and
  professionals on the importance of earthquake
  hazards in the southeast region.
• BACKGROUND
• While hurricanes have historically been the main
  cause of damage to structures located in the
  Eastern and Southeastern United States during the
  June-November period, the probability of
  earthquakes in this region cannot be ignored.
  Believe it or not, earthquake hazard is prevalent
  in this area.
• Most earthquakes occur at the boundaries of
  tectonic plates (e.g., California), however, they
  can occur in inner zones. This is most likely
  caused by the build-up of strains from pressures
  developed at the plate boundaries (Hu 1996). The
  most notable events of this type were the New
  Madrid earthquakes of 1811-1812 and the
  Charleston earthquake of 1886. The four New
  Madrid earthquakes were the largest intraplate
  earthquakes in the world. The Mississippi River
  changed its course, the land surface sunk to form
  new lakes and the violent shaking snapped off
  trees. The Charleston earthquake, whose maximum
  intensity and magnitude were equal to X and 7.3,
  respectively, caused damage for an estimated
  5,000,000 and was felt as far as 160 km away
  from the epicenter. This was the most damaging
  earthquake ever to strike the Eastern United
  States. To date, there have been more than 60
  earthquakes in the Charleston area. On April 13,
  1998, a small earthquake of magnitude 3.9 shook
  Kershaw County, SC, and on April 30, 2003, Fort
  Payne, Alabama experienced a 4.9 magnitude
  earthquake. The quake was felt throughout the
  state, however, there was no damage.
• The probability of another event like the 1886
  earthquake occurring somewhere in the Eastern
  United States is equal to 40-60 in the next 20
  years (Nishenko and Bollinger 1990, Sibol et al.,
  1990). Mitigation of the effects of earthquakes
  is no longer a goal in earthquake-prone areas
  only. Therefore, there is a need to develop a
  methodology to guide future decision-making
  regarding seismic hazard.
• OBJECTIVE
• Analyze the effects of an earthquake on an
  existing structure constructed in the
  southeastern
• region of the United States Turlington Building,
  Tallahassee, Florida.
• Relate building motion to probability of damage.
  
• Approximate the amount of earthquake damage, in
  terms of monetary cost.
• CONTROL TECHNIQUE

• median value of spectral displacement at
  which the building reaches the threshold of
  damage state, ds.
• is the standard deviation of the natural
  logarithm of spectral displacement for damage
  state, ds.
• is the standard normal cumulative
  distribution function.

Structural Damage
Nonstructural Damage
Total Damage from Displacement

• RCS, RCD repair cost to structural and
  displacement-sensitive damage, respectively
• PMBTSTR probability of model building type j
  being in structural damage state ds
• PONSD probability of occupancy I being in
  nonstructural damage state ds
• CI cost index multiplier (local index 0.8)
• FA floor area

(FEMA, 1998)
CHARLESTON RESPONSE
NEW MADRID RESPONSE
Equation of Motion
Base Isolator
Tuned Mass Damper
(Chopra 2001)
(Rana 1998)