Elevator Machine Room Loads 2

[Galambos]

Im designing an elevator machine room for a 14 story building and i have information from the elevator supplier that shows 35,000lbs reactions for equipment for each of my three elevators. I would ask if this seems reasonable to those of you have dealt with elevators before.

i have three of these loads on a 28ft span with a 12 thick slab, in addition to 125 psf LL. Ive come up with a W36, which seemed to be a red flag for me. thoughts?

 

[WillisV]

Those are elevator buffer loads and yes they seem reasonable. You might want to check if they include impact, if not, they should be increased by 100% per IBC 2006 1607.8.1 with reference to ASME A17.1. In addition to the impact loads, you need to design the machine room floro itself for 125psf. Note that there are also extremely tight deflection limits to keep the elevator cabs from bouncing up and down as they reach each floor (ASME A17.1 recommends L/1666 under the static load prior to doubling for impact). A 12" concrete floor supported on W36s is not unreasonable.

 

[jike]

I agree that they seem reasonable. As WillisV said make sure that you design your beams for L/1666 deflection limit.

 

[lkjh345]

WillisV:

Very good summary of design criteria for elevator machine rooms.

I also agree that the stated load does not seem unreasonable.