Table 4. Maximum values of Reduction factor
Structural system 
Structural material 
R 
R_{o} 
Space momentresisting frames 
Structural Steel Reinforced Concrete 
7 7 
11 11 
Shear walls and braced systems 
Structural steel Reinforced Concrete Reinforced Concrete and Confined Masonry  If criterion A is mete  If criterion A is not met
Wood Confined Masonry Reinforced Masonry  Of concrete blocks or units of similar geometry with full grouting and doublewythe masonry.  Of clay bricks with partial or full grouting and concrete blocks or units of similar geometry which have partial grouting. 
7 7
6 4
5.5 4
3

11 11
9 4
7 4
3

Any type of structure or material that cannot be classified in one of the above categories. 
2 
 