Steel Framed Elevator Shaft

[bjb]

Most of the buildings that I have designed had CMU elevator shafts. For the project that I am currently working on the architect wants to have the elevator shaft constructed of metal studs. My thought is to design a steel frame constructed from HSS sections that would be built in the plane of the metal studs. The elevator shaft will not be participating in resisting building wind or seismic loads-it only has to resist lateral loading from the elevator cars. The floor-to floor height is 26 feet, and there are only 2 floors. This is a steel framed building.

The architect is showing 6" metal studs, so I could in theory have up to a 6" HSS.

Does anyone have any experience with something like this?

 

[wannabeSE]

Please verify the 26' floor to floor ( approx. 42' tall shaft). 13' floor to floor is commonly done with CH (shaftwall) studs.

The problem with 6"HSS is installing gyp on the inside of the shaft without scaffolding. If scaffolding is an option, then you might try some heavy 6" studs rather than add HSS. Without scaffolding, try to justify double E studs or CH studs spaced closer than the typical 24" OC (but, the jambs may be challenging)

I am anxious to see if any Eng Tips contributors have done something similar. It sounds like a fun task.

 

[KootK]

I've done the HSS thing twice although I believe it to be a relatively common practice. Lessons learned:

1) The numbers are favorable. One both occasions, cost consultants indicated significant savings versus block/concrete.

2) Watch the deflection criteria. Things that are givens on solid shaft walls require a little more attention in steel.

3) I wouldn't put an HSS bigger than 5" in a 6" CFM wall. Tolerances, tolerances, tolerances.

4) Coordination of the location of my HSS elements killed me. In future, I will specify field welded connections located by somebody else.

5) I got no flack on the scaffolding business. I'll consider that in the future though. If nothing else, I'll look constructability smart.

Lateral loads on the elevator rails result in torsion in HSS posts. How is that handled in CFM studs? Or do you intentionally land the rails on blocking between studs? Certainly, if CFM can work, that seems like the way to go. Both from a cost standpoint and a coordination perspective. Could one just not sheath the inside of the shaft? Maybe use lots of blocking / bridging and two layers gyp on the outside if needed for fire?



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