Two Way Flat Plate system

[dgkhan]

I need to analyse a two way flat plate parking garage. Since the span do not follow Direct design method, I want to model it in STAAD and obtain design moments and shears.
Can I get some tips. Shall I model slab as beam frame. Assign .25 cracked M.O.I? Column joint with slab as Torsional member? what size?

 

[msquared48]

Is this a proposed or an existing garage?

Mike McCann
MMC Engineering

 

[DaveAtkins]

I would use the equivalent frame method (EFM). Each grid line is modeled as an "equivalent frame." STAAD probably will automatically assign reduced stiffness values to the spans and to the columns (something like 0.35Ig and 0.7Ig respectively). Follow ACI regarding torsional stiffness where the slab meets the column.

DaveAtkins

 

[dik]

Equivalent Frame is likely the way to go; you have to be careful of column spacing for both parking stalls as well as location of car doors to maximise utility.

Dik

 

[dgkhan]

msquared48
it is existing garage