THE DESIGN EARTHQUAKE AND EARTHQUAKE RESPONSE SPECTRA

The complexity of estimating the gronud shaking characteristics of the design earthquake is discussed, factors to be considered in selecting a design earthquake are outlined, the functions of the geologist, geophysicist and seismologist are reviewed, and key steps to developing design earthquake response spectra are set forth. In selecting a design earthquake, good estimates are needed for: the maximum magnitude or energy release, the epicentral distance from the nearest active fault zone or tectonic features; the extended peak horizontal ground acceleration; the duration of shaking; and the physical properties of the soil column at the site of interest. The amplitude and spectral characteristics of the estimated ground shaking are defined in terms of the earthquake source mechanism, surface wave dispersion, and duration of shaking, the soil amplification effects are specified in the form of response spectra. The latter represent the peak response of an ensemble of single-degree-of-freedom systems having viscous damping to an input ground motion. The key steps in developing earthquake response spectra are: determine the seismicity of the area, locate and determine the characteristics of faults and tectonic features of the area, estimate the maximum ground shaking levels expected at the site; estimate the ground motion response spectra expected for the site; estimate the local soil amplification effects; and modify the design response spectra if necessary. A flow diagram is presented of steps to develop a design earthquake ground motion response spectrum.

  • Authors:
    • Hays, W W
  • Publication Date: 1974-8

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00134666
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 23 1976 12:00AM