Table Canada 2 
Seismic Response Factors

T

Za/Zy

S

≤ 0.25

> 1.0
1.0
< 1.0

4.2
3.0
2.1

> 0.25 but < 0.50

> 1.0
1.0
< 1.0

4.2-8.4 (T-0.25)
3.0-3.6(T-0.25)
2.1

≥ 0.50

All values

1.5/t1/2

The foundation factor, F, shall conform to Table 3, except that the product F・S need not exceed
 a) 3.0 where Za does not exceed Zv and
 b) 4.2 where Za is greater than Zv