Type

Building Characteristics

Nd

Rd

I

Reinforced concrete buildings having ductile frames. They are able to resist 100% of the horizontal force, considering that they work independently of any of the other rigid elements.
Steel frame buildings.

3
2
1

6
4.5
2.5

II

Reinforced concrete buildings having special ductile frames and special shear walls designed according to the following criteria:
— The frames and shear walls should resist the total horizontal force according to their relative stiffness taken into account the interaction between frames and shear walls.
— The frames should have enough capacity to resist not less than 25% the horizontal force, if they act independently.

3
2
1

5
3.75
2

III

Reinforced concrete buildings similar to the previous case, except that their frames        and/or shear walls do not satisfy completely the special ductility requirements.
— Wooden and steel structures which are not included in other cases.

3
2
1

4
3
1.5

IV

Building where only shears walls or similar structures take the horizontal force.

3
2
1

4
4
4

V

Masonry reinforcement buildings.

3
2
1

3.5
3.5
3.5

VI

Confined buildings in masonry cement.

3
2
1

2.5
2.5
2.5

VII

Confined building without reinforcement.
— Adobe buildings and others not included in this classification.

3
2
1

1.5
1.5
1.5