Seismic Loads for Intermediate Mezzanine
Seismic Loads for Intermediate Mezzanine
(OP)
I have a large building - 3 floors each with about 300,000 sf. Between the second floor and the roof there is a small (8000 sf) mezzanine attached to the columns.
Under IBC 2000, how do you determine the lateral seismic force on this small mezzanine? I can get the story forces for each level based upon the overall building - just not sure if the mezzanine counts as a "level" or if its mass gets added to the main floors and the seismic load is calculated separately (to check the columns) as an Architectural component?
Under IBC 2000, how do you determine the lateral seismic force on this small mezzanine? I can get the story forces for each level based upon the overall building - just not sure if the mezzanine counts as a "level" or if its mass gets added to the main floors and the seismic load is calculated separately (to check the columns) as an Architectural component?






RE: Seismic Loads for Intermediate Mezzanine
RE: Seismic Loads for Intermediate Mezzanine
RE: Seismic Loads for Intermediate Mezzanine
RE: Seismic Loads for Intermediate Mezzanine
RE: Seismic Loads for Intermediate Mezzanine
I am actually a Canadian engineer, however I'm working in New Zealand. Some of the world's most ground breaking seismic work has been done, and continues to be done, here in New Zealand. Tom Paulay, one of the team of Professors at Canterbury University here in Christchurch who created Capacity Design has been quoted as saying that something to the effect of, and I am paraphrasing here, "Forget the last 10% of an earthquake. An earthquake doesn't know about the last 10%; It's much more important that the structure knows how to behave when in an earthquake than the structure has the capacity to resist forces who's calculation is in the end arbitrary." Basically if you make sure that your plastic hinges can dissipate energy, there is no soft storey mechanism and (if in Reinforced Concrete) the detailing allows for the capacity design assumed behaviour to occur, you're good even if you acheive a capacity 10%.
Good luck,
Let us know what you choose to do!
YS
B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...
RE: Seismic Loads for Intermediate Mezzanine
But it is nice to see we're pretty close to agreement on how such a scenario should be handled.
Regards,
YS
B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...
RE: Seismic Loads for Intermediate Mezzanine
So do I use Arch component forces from the IBC or what? How does one take the mezzanine mass and get a demand from it?
The IBC takes the total base shear and distributes it to the various levels. Since the mezzanine isn't a "level" then I can't use that approach.
RE: Seismic Loads for Intermediate Mezzanine
RE: Seismic Loads for Intermediate Mezzanine
RE: Seismic Loads for Intermediate Mezzanine
Though the area of the mezzanine is small relative to the whole building area, 8000 sf isn't that small. It is too large as a "component" and too small to be considered a "level".
RE: Seismic Loads for Intermediate Mezzanine