- See Section 2.39.
- Response parameter is pseudo-velocity for 5% damping.
- Use same data and method as Joyner and Boore (1982a).
- Restrict regressions to T ≤ 4s to avoid problems due to record-processing errors.
- Find that coefficient for quadratic term is not statistically significant at 90% level for most periods but
the values obtained at different periods are sufficiently consistent to warrant inclusion of this term. Note
that maximum difference with and without quadratic term is about 20%.
- Include soil term at short periods even though not significant at 90% level.
- Smooth coefficients by plotting them against log T and drawing smooth curves.