R. C. Lee

Site-specific probabilistic seismic hazard assessments (PSHAs) and associated seismic design bases are critically dependent upon the local geological and geotechnical model. For reactor and critical non-reactor facilities on soil or softrock sites exhibiting strain-dependent behavior, estimates of site response can change significantly as site measurements and inferred structure evolve.

Seismic design requirements for critical facilities normally require the development and application of a uniform hazard spectrum having a specified return period. For a soil site, hazard results are often evaluated for bedrock level and soil surface.