4.1.8.15.(1)

Intent 1:

To limit the probability that the design of a floor or roof acting as a diaphragm will not take into account the maximum expected seismic forces tributary to that storey which will be transferred through the diaphragm into the Seismic Force Resisting System, which could lead to:

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

Intent 2:

To limit the probability that the openings in the diaphragm or the shape of the diaphragm will not be taken into account in its design for earthquake, which could lead to stress concentrations, which could lead to:

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