India Table 4
Values of Basic Seismic Coefficients and Seismic Zone Factors in Different Zones
(see Fig. 2)

SL
No.

Zone No.

Method

Seismic Coefficient Method

Respones Spectrum Method
(see Appendix F)

Basic horizontal seismic coefficient, αo

Seismic zone factor for average acceleration spectra to be used with Fig. 3, Fo

(1)

(2)

(3)

(4)

i)

V

0.08

0.40

ii)

IV

0.05

0.25

iii)

III

0.04

0.20

iv)

II

0.02

0.10

v)

I

0.01

0.05

Note
For under ground structures and foundations at 30m depth or below, the basic seismic coefficient may be taken as 0.5αo ; for structures placed between ground level and 30m depth, the basic seismic coefficient may be linearly interpolated betweenαo and 0.5αo. The seismic coefficients for some important towns and cities are given.