Sentence 4.1.8.11.(6)

Intent 1:

To limit the probability that the calculation of the equivalent static base shear will not take into account the participation of higher modes in the dynamic response of the structure by the inclusion of the factor M_v, which could lead to:

• the excessive deformation of, or excessive stress in, the structural elements, which could lead to damage to the building, or
• the excessive deformation of, or excessive stress in, the building structure, which could lead to damage to the building, which could impede the intended use and occupancy of the building.

Intent 2:

To modify the calculation for the overturning moment at the base of the structure, on the basis that the higher modes included in the base shear do not contribute significantly to the base overturning moment.