Campbell & Bozorgnia (2008)

Description: 

This Attenuation Relationship is one of the PEER NGA Models. The OpenSHA implementation has been verified using Ken Campbell's NGA test files.

Reference: 

Campbell, K. W. and Y. Bozorgnia (2008), NGA ground motion model for the geometric mean horizontal component of PGA, PGV, PGD and 5% damped linear elastic response spectra for periods ranging from 0.01 to 10s, Earthquake Spectra, 24(1), 139-171.

Supported Intensity Measure Types (IMTs): 
SA damping (5%) at the following periods:
  • 0.01
  • 0.02
  • 0.03
  • 0.05
  • 0.075
  • 0.1
  • 0.15
  • 0.2
  • 0.25
  • 0.3
  • 0.4
  • 0.5
  • 0.75
  • 1.0
  • 1.5
  • 2.0
  • 3.0
  • 4.0
  • 5.0
  • 7.5
  • 10.0
Required Parameters: 
Earthquake Rupture
Site
  • Vs30 (applicable range is 180 to 1500 m/sec)
  • Depth 2.5 km/sec (if unknown, value defaults to 2 km for Vs30 < 2500 m/sec, and 0 otherwise)
Propagation-Effect
Other
Parameter values are numeric unless otherwise indicated with options. If only one option is presented, the value is fixed for this attenuation relationship.
Model Details: 

Distance notes: The OpenSHA implementation of this NGA model uses the (distRup - distJB) / distRup parameter in place of DistanceJB. The reason is that in some applications (e.g. Attenuation Relationship Plotter), where one can plot intensity-measure levels as a function of one parameter while holding others constant, it is illogical to hold DistanceJB constant while allowing DistanceRup to vary. This modification, however, does not change how hazard is computed using this model.

Other notes: The OpenSHA implementation honors the author's stipulation on p. 147 of their paper that if SA > PGA and T ≤ 0.25s, SA should be set equal to PGA "to be consistent with the definition of pseudo-absolute acceleration".