Multi-equation structure per BM23 (Soil Dynamics and Earthquake Engineering 168, 107835, DOI 10.1016/j.soildyn.2023.107835): Eq (10): ordinary motions, PGV <= 115 cm/s Eq (6): D100 max-component, PGV > 115 cm/s Eq (7): D50 median-component, PGV > 115 cm/s with a sub-regime split at PGV = 150 cm/s within Eqs (6) and (7).
Arguments
- ky
Yield acceleration (g).
- Ts
Fundamental period (s).
- Sa
Spectral acceleration at 1.3 * Ts (g).
- PGA
Peak ground acceleration (g).
- PGV
Peak ground velocity (cm/s).
- Mw
Moment magnitude (default 6.5).
- NFC
Near-fault component: "D100" (default; max-component, slope within 45 deg of fault-normal) or "D50" (median-component, other orientations). Used only when PGV > 115 cm/s.