State-of-the-Art for Assessing Earthquake Hazards in the United States. Report 29: Selection of Earthquake Ground Motions for Engineering
Abstract
Earthquake ground motions for major engineering projects are based on a thorough evaluation of geologic hazards to identify earthquake sources and to estimate the earthquake potential of each. Earthquake ground motions are assigned to the sources by either deterministic or probabilistic procedures. A deterministic evaluation takes the maximum credible earthquakes from each source and attenuates the motions to the site. Accelerograms and/or response spectra are assigned to represent analogous earthquake excitations at the site. The objective is to design against any reasonable eventuality, regardless of time, because there is no way to know when the earthquake may or may not happen during the design lifetime of a critical structure. A probabilistic evaluation includes the element of time in the assessment of an earthquake threat. Simple probability is based on projections of b-values. More complex probabilities involve adjustments to the b-values. None of these is reliable. The deterministic method is used for assigning earthquake ground motions for critical structures in seismically active areas. Simple probability, based on seismic hazard maps, can be used for non-critical structures for areas of low seismic threat. (MM)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1995
- Accession Number
- ADA299669
Entities
People
- E. L. Krinitzsky