Category II Loads 1

[SmithJ]

Hi All,

IBC 2000 requires that the importance factors for Seismic, Snow and Wind be increased for Category II Buildings (1.25, 1.1 and 1.15). This is in Table 1604.5 of the code.

My question is the code does not make direct reference to occupancy and live loads for mezzanine design. I have a category II building where I will be increasing the importance factors for the Seismic, snow and wind design. How do I address the mezzanine design of the building? Do I simply use the live loads prescribed in Table 1607.1 without regard to the occupancy category of the building.

Thanks in advance.

 

[JAE]

There are no importance factors for live loads....unless you as the engineer wish to include them.

In most cases, the live loads required by the building codes (such as IBC) and the associated live load factors (if you are using ultimate strength design) are more than adequate for most cases.

There may be some cases, however, where the live loads that are anticipated might be considered highly variable for whatever reason. You as the engineer can be prudent and use a bit higher load factor (which is all that an importance factor generally is).