Final Project Summary — PEER Lifelines Program
Project Title—ID Number

NGA Data Sets—1L02

Start/End Dates

11/1/02 – 12/31/03 Funding Source

Project Leader (boldface) andOther Team Members

Walter Silva (PEA)

Budget/$215,722/ PG&E-CEC

1. Project goals and objectives
The project goal is to update the existing PEER strong motion dataset for use in developing the next generation ofempirical attenuation relations for the PEER-NGA project. This project involves first updating and adding metadata(e.g. earthquake source, wave propagation path and recording and site parameters). Second, new earthquake/site
metadata will be added. In addition, comparison of PEER strong motion dataset time histories and spectra weremade to corresponding USGS and CGS values.
2. Benefits of the results of this project to develop technologies and protocols to mitigate thevulnerability of electric systems and other lifelines to damage directly and indirectly caused byearthquakes. Also, benefits to develop assessment techniques to evaluate damage to electric
systems caused by earthquakes and to assess fiscal impacts due to the loss of electric service tothe community.
Attenuation relationships are the backbone of modern earthquake hazard assessment. These relationships are usedin all earthquake hazard assessment ranging from the U.S. national and California seismic hazards maps, (the latterproduced jointly by the USGS and CGS), to site-specific assessments, both deterministic and probabilistic, used forspecific facilities ranging from bridges to dams to power plants and other electrical systems. Hazard assessment
results are used to establish design strategies and details of the build environment and to predict their performance.
3. Brief description of the accomplishments of the project
The PEER strong motion data set currently consists of over 10700 time histories (acceleration velocity,displacement) (Figure 1) and response spectra (Figure 2) from 175 earthquakes (magnitude M 4.37 to 7.9) at 1580
recording sites. All data were put into a common format for ease of use. A catalog and various spreadsheets
provides the supporting metadata including Vs 30, fault mechanism (strike, dip, rake) and many other parameters.
4. Describe any instances where you are aware that your results have been used in industry
The database is currently being used in the PEER-NGA project to produce the next generation of attenuation
relations for the western U.S.
5. Methodology employed
The methodology employed was to augment the PEER data set with strong motion recordings that were readily
available from data providers (e.g. USGS, CGS, USC) on the www or other electronic media. Also, metadata (e.g.
source, path and site information) were requested and received from leading attenuation modelers, seismologists andengineers. An extensive literature and web search for ground motion data and metadata was also performed.
6. Other related work conducted within and/or outside PEER
Substantial amounts of strong motion data and metadata collected during this project were provided by otherorganizations and individuals (e.g. PE&A, USGS, CGS).
7. Recommendations for the future work: what do you think should be done next?
Continue to expand and update the PEER strong motion data set with additional earthquakes and metadata.
8. Author(s), Title, and Date for the final report for this projectNot completed.

1Figure 1. Acceleration, velocity and displacement time histories from the 1999 Hector
Mine, CA earthquake at the closest station. The time history was processed at PE&A toretain static displacement offsets.

2Figure 2. 5% damped response spectra at Hector. The Comp 000 spectrum isfrom the acceleration time history of Figure 1.

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