Study of Ground Motions at Soil Sites during Two California Earthquakes.
Abstract
Nine strong motion accelerograms recorded at rock and soil stations during two California earthquakes are analyzed using recently developed processing techniques. These techniques study the characteristics of the records in the time domain, including graphs of the buildup of energy of the horizontal acceleration with time, the variation with time of the RMS horizontal acceleration, and the variation with time of the angle between the principal axis of the ground acceleration and the vertical axis. The comparisons of the graphs showed that the wave arrivals are generally consistent between stations during the strong part but that some soil accelerograms have additional significant motions after t sub 2. The consistency of wave arrivals during the strong part was especially good for the 1971 San Fernando records in the Pasadena Area. There, the strongest wave arrival occurred at all four stations considered, approximately 3 seconds after the first S-wave arrival. Several one-dimensional site response simulations were performed at some of the soil stations studied, using the equivalent linear approach. The results showed that the simulated soil accelerations essentially preserve the time domain features of the input rock motion. One consequence of this was that the simulations predicted reasonably well the characteristics of soil motions in the strong part, but did not predict the additional soil motions after T sub 2.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1979
- Accession Number
- ADA077629
Entities
People
- Ricardo Dobry
- Sohan Singh
- William E. Bond
Organizations
- Rensselaer Polytechnic Institute