The Earthquake Engineering Online Archive

The attenuation of strong ground motion displacements

Gregor, Nicholas J.

UCB/EERC-95/02, Earthquake Engineering Research Center, University of California, Berkeley, 1995-06, 227 pages (410/G734/1995)

The attenuation of the maximum shear wave for strong ground displacements for large earthquakes (M subscript W greater than 5.4 and less than 7.2) in California was studied from a seismological viewpoint, and regression curves of attenuation were statistically estimated. The curves were computed for two different geologic classifications of the recording location (rock or soil), and two different fault mechanisms of the seismic source (strike-slip or reverse-fault). The sample consisted of eight strike-slip and four reverse-fault mechanism earthquakes with 238 soil and 100 rock measurements. The peak ground-motion displacements were measured from the S body-wave portion of the seismograms (typical frequencies of 0.2 - 1 Hz) after seismic wave-type discrimination. The peak displacement from the surface wave energy was not considered in this analysis. A defined attenuation distance, H subscript slip, was used as the distance from the recording station to the location on the fault plane of largest slip. A total of eight attenuation relations, based on source mechanism, site geologic condition, and horizontal (SH) versus vertical (SV) ground motion, were statistically estimated.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-95-02.pdf (17 MB)