Response Spectrum Generator

Pick the seismic zone, soil profile and near-source factors, and the app builds the NSCP 2015 design response spectrum — the seismic coefficients C_a, C_v, the corner periods T₀ & T_s, the spectral acceleration S_a(T) at any structure period, and a labelled spectrum plot.

⭐ Free to generate · Balance … EP

⚠️ Educational tool — confirm coefficients against NSCP 2015. C_a and C_v come from NSCP 2015 Tables 208-7 & 208-8 (Zone 4 values are multiplied by the near-source factors N_a, N_v). You can override any value. Always verify against the official code and your instructor.

① Seismic site parameters

Seismic zone (Z)

Soil profile type

Near-source N_a (Zone 4)

Near-source N_v (Zone 4)

N_a, N_v apply only in Zone 4 (default 1.0 if > ~10–15 km from a known source). In Zone 2 they are taken as 1.0.

② Optional overrides

C_a override

C_v override

Structure period T (s) opt.

Enter your structure's fundamental period T to read S_a(T) off the spectrum. Leave overrides blank to use the table values.

🌐 Design response spectrum

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NSCP 2015 §208 general design spectrum

Seismic coeff. C_a

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Seismic coeff. C_v

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Peak S_a = 2.5C_a

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Corner T₀

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Corner T_s

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S_a at T

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Spectral ordinates

Period T (s)	S_a (g)	Branch

Response Spectrum Generator

① Seismic site parameters

② Optional overrides

🌐 Design response spectrum

Spectral ordinates

Worked solution