Report - PEER - University of California, Berkeley

included in Appendix A. Due to the lack of consistent information for all the sites, thesubdivision of Site D into a very deep site sub-category (D 3 ) was omitted. Additionally,sufficient information was not available to categorize sites by a precise depth to bedrockparameter, so that a regression analysis could not be performed using this parameter as acontinuous variable.The references listed in Appendix A were complemented with site visits for someof the sites where information was incomplete. A list of the visited sites is given inAppendix B. Note that an important source of information, particularly for sitesbelonging to the University of Southern California, was the database of Vucetic andDoroudian (1995). The shear wave velocity values presented in this database haverecently been challenged (e.g., Wills 1998, Boore and Brown 1998). In light of theseobservations, the shear wave velocities for these sites were used, whenever possible, onlyas a secondary reference. For those sites where the only data available was those in theVucetic-Doroudian database, these shear wave velocity data were used incorporating thecomments made by Boore and Brown (1998).GROUND MOTION DATAGround motion data from two recent earthquakes, the 1989 Loma PrietaEarthquake and the 1994 Northridge Earthquake, were used in this study. The groundmotion recordings were obtained from a database provided by Dr. Walter Silva fromPacific Engineering and Analysis (personal comm. 1998). The database consists ofcomputed elastic spectral acceleration values at 5% damping.9