- Ground-motion model used is:
- Response parameter, Y , is pseudo-velocity for 5% damping
- Use data from Sabetta and Pugliese (1987).
- Remove anelastic decay term because it was not significant at α = 0.1 and sometimes it was positive.
Originally geometrical decay coefficient c was allowed to vary but find it is close to -1 so constrain.
- Use three site categories:
S1 = 1,S2 = 0
Shallow: depth H ≤ 20m alluvium 400 ≤ V s ≤ 800m∕s.
S1 = 0,S2 = 1
Deep: depth H > 20m alluvium 400 ≤ V s ≤ 800m∕s.
S1 = 0,S2 = 0
Stiff: V s > 800m∕s.
- Accelerograms digitised at 400 samples/sec. Bandpass frequencies chosen by an analysis of signal and fixed
trace Fourier spectra. fmin between 0.2 and 0.7Hz most about 0.3Hz and fmax between 20 and 35Hz most
about 25Hz. Instrument correction applied.
- Use one-stage method although two-stage method yields similar results.
- Also present smoothed coefficients.