Seismic Response Spectrum

Generate acceleration response spectrum curves from site class, zone factor, and damping ratio. Visualize spectral acceleration vs natural period — free earthquake engineering tool

Site Classification

Type I (Rock)Type II (Medium)Type III (Soft)

Design Parameters

Seismic Zone Factor Z

Damping Ratio h

Typical buildings: h = 0.05

Acceleration Response Spectrum

Key Points

Short Period Plateau

31.4 m/s²

T = 0.1 ~ 0.6s

Corner Period Tc

0.60 s

Start of 1/T decay

Long Period Tl

0.96 s

Start of 1/T² decay

Spectrum Data

Period T (s)	Sa (m/s²)	Sa (gal)
0.00	9.81	981.0
0.02	14.13	1412.6
0.04	18.44	1844.3
0.06	22.76	2275.9
0.08	27.08	2707.6
0.10	31.39	3139.2
0.12	31.39	3139.2
0.15	31.39	3139.2
0.20	31.39	3139.2
0.25	31.39	3139.2
0.30	31.39	3139.2
0.35	31.39	3139.2
0.40	31.39	3139.2
0.45	31.39	3139.2
0.50	31.39	3139.2
0.60	31.39	3139.2
0.70	26.91	2690.7
0.80	23.54	2354.4
0.90	20.93	2092.8
1.00	18.08	1808.2
1.20	12.56	1255.7
1.40	9.23	922.5
1.60	7.06	706.3
1.80	5.58	558.1
2.00	4.52	452.0
2.50	2.89	289.3
3.00	2.01	200.9
3.50	1.48	147.6
4.00	1.13	113.0
4.50	0.89	89.3
5.00	0.72	72.3
5.50	0.60	59.8
6.00	0.50	50.2