Overturning Force Calculation

The overturning component of the hold-down force is calculated by

F = Vh / L'

where

• V is the total factored shear force on the wall segment,
• h is the height of the shear wall plus the joist depth, as shown in O86 Figure 11.7. Refer also to wall heights at gable ends.
• L' the length of the wall between the hold-down tension force location at one end and the compression force in the end studs at the other end = L - O_t - O_c where L is the segment length, O_t is the hold-down offset at the tension end and O_c is the compression force offset .

This can also be expressed as

F = vh * L / L'

where v is the factored shear force per unit distance.

Seismic Amplification

For buildings in high seismic zones, this force is multiplied by 1.2. See Seismic Overturning Force Amplification.