The Earthquake Engineering Online Archive

Characteristics of rock motions during earthquakes

Seed, H. Bolton; Idriss, I. M.; Kiefer, Fred W.

UCB/EERC-68/05, Earthquake Engineering Research Center, University of California, Berkeley, 1968-09-01, 39 pages (450/S41/1968)

The primary objective of the report is to suggest simple but effective techniques for assessing the characteristics of rock motions developed during earthquakes. The data presented in two figures, predominant periods for maximum accelerations in rock and variation of maximum acceleration with earthquake magnitude and distance from causative fault, provide a basis for such an assessment. It is recognized that more sophisticated techniques can be utilized but it is believed that the simple procedures described in the report will prove adequate for many engineering purposes. The good agreement between the significant characteristics of the computed and recorded surface motions at El Centro in conjunction with similar satisfactory comparisons in a number of other cases would seem to indicate: (1) the utility of the data on predominant periods and variation of maximum acceleration and the proposed method of constructing accelerograms for providing a reasonable representation for analytical purposes of rock motions during earthquakes and (2) the ability of dynamic response analyses, incorporating appropriate values of strain-dependent material properties, to make realistic predictions in many cases of response spectra for ground surface motions developed during earthquakes.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-68-05.pdf (3 MB)