Multiple Fire Rated File Cabinets & Floor Loading 1

[jcosse]

I'm a mechanical engineer (facility engineer) and have a question regarding office space floor loading. I have a client who wants to store 10 fire-rated file cabinets in a room 12'x18'. Bldg is concrete construction, with office space floor loading of 100 psf. Column spacing is 30' x 33', and the storage room corners on a concrete building column. File cabinets weigh 900 # empty, but I assume around 1,500 # full. Each cabinet is roughly 18" x 42". I've seen some info regarding placement of one such cabinet not being a problem, but nothing on storing multiple cabinets side by side. Can anyone help regarding floor loading for a group of such cabinets?

 

[JAE]

A couple of thoughts on this:

1. 100 psf is not used in the building codes as "office" loading so you might want to verify what it actually was designed for.

2. The placement of multiple concentrated loads on a concrete suspended structural floor cannot simply be looked at by comparing your 100 psf capacity against the psf generated by the cabinets (1500lbs / (18"x42&quot/144) = 285 psf. The actual type of concrete system, along with its reinforcing would have to be studied against the applied loads of the cabinets and some uniform live load AROUND the cabinets (say 50 psf office LL).

With this loading, individual slabs, joists, and/or beams would have to be analyzed and the designs checked against the applied moments and shears.

More complicated than the psf comparison and it takes someone in the know...i.e. a structural engineer to properly do the task. Do you have an SE to turn to for this? That would be my recommendation.

 

[dbuzz]

Australian practice (AS1170.1:2002) specifies the following.

Free rolling office compactus, for general filing, up to 2m high
Uniform: 3.0kPa (63 psf) for each metre of storage height
Concentrated: To be calculated

File rooms, office storage space, vaults and strongrooms
Uniform: 5.0kPa (104 psf)
Concentrated: 4.5kN (1 kip)

Mobile stacking, mechanically operated heavy shelving (wheels on rails, e.g. compactus)
Uniform: 4.0kPa (84 psf) for each metre of storage height but not less than 10.0kPa (209 psf)
Concentrated: To be calculated

 

[jcosse]

Thanks much for the replies. The structure is a 9 story office building of concrete construction. Built around 1995. The floor was designed for 100 psf. The client wants to place his fire rated cabinets in the same small room on the 4th floor. I was wondering if there was a rule of thumb or guideline for such concentrated storage, but it sounds like I better refer this to my local SE's for a more detailed evaluation. Thanks again.