The Earthquake Engineering Online Archive

Relationships between maximum acceleration, maximum velocity, distance from source and local site conditions for moderately strong earthquakes

Seed, H. Bolton; Murarka, Ramesh P.; Lysmer, John; Idriss, I. M.

UCB/EERC-75/17, Earthquake Engineering Research Center, University of California, Berkeley, 1975-07, 45 pages (450/S41/1975)

This report presents the results of a study to determine the influence of local geologic conditions on the attenuation of peak accelerations and peak velocities, with increasing distance from the source of energy release for earthquakes with a magnitude of about 6.5 occurring in the western part of the United States. While the results can only be considered to be strictly applicable to these conditions, it is hoped that they can also serve as a guide to possible relationships between peak accelerations and peak velocities which may be expected for earthquakes of higher magnitudes occurring in different locations, and thereby serve a useful purpose in the difficult task of predicting the likely characteristics of earthquake ground motions in different geologic settings. In this respect, however, it should be noted that while near epicentral values for higher magnitude earthquakes may not change significantly, different attenuation rates, both for peak velocity and peak acceleration are to be expected for earthquakes with different magnitudes and in different geologic zones. The good degree of agreement between the results of this study and those of other investigators, however, gives added confidence that the results might be expected to provide a realistic basis for assessing the characteristics of earthquake ground motions for a wide range of soil and geologic conditions.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-75-17.pdf (2 MB)