Abrahamson (2000)

Reference: 

Abrahamson, N. A. (2000), Effects of rupture directivity on probabilistic seismic hazard analysis, Proceedings of the 6th International Conference on Seismic Zonation, Palm Springs, CA, Earthquake Engineering Research Institute (EERI).

Supported Intensity Measure Types (IMTs): 
SA damping (5%) at the following periods:
  • 0.0
  • 0.01
  • 0.02
  • 0.03
  • 0.04
  • 0.05
  • 0.06
  • 0.075
  • 0.09
  • 0.1
  • 0.12
  • 0.15
  • 0.17
  • 0.2
  • 0.24
  • 0.3
  • 0.36
  • 0.4
  • 0.46
  • 0.5
  • 0.6
  • 0.75
  • 0.85
  • 1.0
  • 1.5
  • 2.0
  • 3.0
  • 4.0
  • 5.0
Required Parameters: 
Earthquake Rupture
Site
  • Type: [Rock/Shallow-Soil, Deep Soil]
Propagation-Effect
  • DistanceRup
  • On Hanging Wall [true, false]
  • X (length-ratio directivity)
  • Theta (angle between fault and ray path directivity)
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: 

If the Earthquake Rupture related parameters are set from an Earthquake Rupture object, the hypocenter of the latter must have been set (otherwise directivity parameters cannot be computed). This model works only for strike-slip earthquakes (even though Somerville et al. (1997) handles all types), and is implemented only for the average horizontal component. It would be possible to add fault normal and fault parallel components as well, but the specs would have to be obtained from the author as the necessary info is not contained in the associated paper. SA periods down to 0 are included even though the directivity effects are zero below 0.6 sec (PGA is not an option for this reason). See the above referenced publication for more information.