What it calculates
SelectEQ prepares a target spectrum, preselects records from databases and reports fit measures for the selected suite.
- Greedy suite, top records, PGA, single-period and period-band strategies
- Horizontal and optional vertical record comparison
- Target scale factors, fit error and suite summary
Inputs
Set a target spectrum and record-selection criteria, then choose the available databases and filters.
- Manually entered T-Sa or T-Sa-sigma series
- TBDY 2018, Eurocode 8, ASCE 7-22, NBC or CMS target
- CMS inputs T*, Sa(T*), Mw, Rjb, Vs30 and GMPE
- Filters for Mw, Rjb, Vs30, PGA, mechanism and lowest usable frequency
Outputs and reports
Results include selected record IDs, spectra, scale factors and suite-level fit summaries.
- Target and selected-record spectra with record metadata
- Horizontal/vertical scale factors, fit measures and suite summary
- Convergence details and optional candidate list
- CSV tables, reports and project interchange formats
Validation
SelectEQ documentation separates the database RotD50 spectrum comparison from validation of the record-selection algorithm.
- The NGA-West2 RotD50 database check reports about 2.53e-08 mean ln(Sa) RMSE and about 3.29e-08 maximum ln(Sa) RMSE across 21,335 valid rows.
- This check compares stored spectra with the source flatfile; it does not independently validate the complete selection and scaling algorithm.
- CMS/CS generation, AFAD/ESM spectra and external scaling comparisons are listed as pending.
Who it is for
SelectEQ is intended for earthquake and geotechnical engineers selecting a ground-motion suite for a target spectrum.
- Engineers working with Sa, PGA and RotD50
- Teams reviewing record filters and suite results against engineering criteria
Frequently asked questions
What if too few records remain after filtering?
The guide suggests loosening filters, adding a database or reducing the requested number of records.
Are AFAD and ESM databases available on every plan?
The databases available for selection vary by plan. Geoproje does not distribute acceleration time histories; you download the selected records from the source site with your own account.
What can a scale factor of 1.000 mean?
Scaling may be disabled or the selected record may already be close to the target; review the factor with the other plots and measures.
Can I compare one horizontal component directly with NGA-West2 RotD50?
No. The documentation says RotD50 comparisons use both horizontal components.