Summary of the Abrahamson & Silva NGA Ground‐Motion Relations

Empirical ground‐motion models for the rotation‐independent average horizontal component from shallow crustal earthquakes are derived using the PEER NGA database. The model is applicable to magnitudes 5–8.5, distances 0–200 km , and spectral periods of 0–10 sec . In place of generic site categories (soil and rock), the site is parameterized by average shear‐wave velocity in the top 30 m (V S 30 ) and the depth to engineering rock (depth to V S =1000 m/s). In addition to magnitude and style‐of‐faulting, the source term is also dependent on the depth to top‐of‐rupture: for the same magnitude and rupture distance, buried ruptures lead to larger short‐period ground motions than surface ruptures. The hanging‐wall…

• NS
  National Science Foundation
• UD
  U.S. Department of Energy
• CD
  California Department of Transportation