Resources · Research Data

Ground motion sets

The complete FEMA P-695 (ATC-63) ground motion sets — far-field, near-field, and an expanded far-field set — with time histories, spectra, and documentation.

Far-field 22 motions · Near-field 28 motions · Expanded far-field 39 pairs

All three sets are described in Appendix A of the FEMA P-695 (ATC-63) report: the standard far-field set (22 motions), the near-field set (28 motions), and the expanded far-field set (39 motion pairs) developed in our research.

FEMA P-695 (ATC-63) far-field set

The 22-motion far-field set is provided as documentation, acceleration time histories in three formats, and acceleration spectra in two formats.

Summary file

Record information and documentation. Excel (.xls)

Time histories — Excel format

Acceleration time histories for all 22 motions. ZIP

Time histories — original PEER-NGA text files

Unscaled acceleration text files as delivered by PEER-NGA. ZIP

Time histories — sorted text files

Unscaled acceleration text files, sorted for batch analysis. ZIP

Spectra — Excel format

Acceleration spectra for all records. Excel (.xls)

Spectra — MATLAB format

Sa spectra files for MATLAB. ZIP

FEMA P-695 (ATC-63) near-field set

The 28-motion near-field set, also described in Appendix A of the FEMA P-695 report.

Summary file

Summary table and normalization scale factors. Excel (.xls)

Ground motion properties

Properties information for each record. Excel (.xls)

Response spectra summary

Response spectra for the full set. Excel (.xls)

Sorted acceleration-history files

Sorted earthquake acceleration-history text files. ZIP

Response spectra — MATLAB format

Response spectra files for MATLAB. ZIP

Expanded far-field set

In our research and related work, we developed a general far-field ground motion set for use in structural analyses and performance assessment: 39 pairs of horizontal ground motions (78 components total). It includes the 22 motion pairs of the FEMA P-695 (ATC-63) far-field set, which was created in parallel with this research and has more extensive documentation available above and from the Applied Technology Council.

We selected this set (called "Basic Far-Field Set" or "Set FFext") to consist of strong motions that may cause structural collapse of modern buildings — typically extremely large levels of ground motion. To ensure the records represent such motions, we imposed minimum limits on event magnitude, peak ground velocity, and peak ground acceleration, balanced against keeping enough records in the set.

Selection criteria for the expanded far-field set

  • Magnitude > 6.5

  • Distance from source to site > 10 km (average of Joyner-Boore and Campbell distances)

  • Peak ground acceleration > 0.2g AND peak ground velocity > 15 cm/sec

  • Soil shear wave velocity, in upper 30 m of soil, greater than 180 m/s (NEHRP soil types A–D; note that all selected records happened to be on C/D sites)

  • Limit of six records from a single seismic event; if more than six records pass the initial criteria, the six records with largest PGV are selected, but in some cases a lower-PGV record is used if the PGA is much larger

  • Lowest usable frequency < 0.25 Hz, to ensure the low-frequency content was not removed by the ground motion filtering process

  • Strike-slip and thrust faults (consistent with California)

  • No consideration of spectral shape (ε)

  • No consideration of station housing, but PEER-NGA records were selected to be "free-field"

Set documentation table

The full table documenting the expanded far-field set. Excel (.xls)

Ground motion files

Acceleration time history files plus time-step and point-count files for each record. ZIP

More research resources

OpenSees structural models, calibration tools, and collapse simulation videos from the same research program.

Research Tools → Structural Model Database