any issue with C8 channel stair stringer connecting to angle L2.5 beam?

[delagina]

this is for a very small access platform. size is 4'x4' x 6' high.
we don't show detail and let detailer/fabrication figure out the connection and we've done this a lot of times with no issues.
but I wonder what is the proper connection for this.

 

[JedClampett]

Don't know how you can get enough bolts or weld to support a stair, short or not.
It might work, but it wouldn't look good and I wouldn't do it.

 

[delagina]

i'll change it to L6x4.

 

[KootK]

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[Ron]

Not sure what your application is, whether industrial or commercial, but a C8 is rather shallow for a stair stringer. Usually either MC10 or 12. Take a look at deflection and designing for "pedestrian comfort". Stair will likely be "bouncy". This will place additional stress on your connection.

 

[thaidavid40]

I'm just wondering how he is getting a standard-width stair tread to fit on a C8 member?
Dave

Thaidavid

 

[SteelPE]

In KootK's detail it will not take much weld to get the system to work. In most stairs as single bolt or a few inches of weld are all that's needed. I usually have the fabricator provide much more than what is needed just for comfort, but the forces are never that large. I doubt yours will be either (at 6' high).

Actually I have a colleague who uses a L2.5 x 2.5 "carrier angle" to attach his stringers to his landings (similar detail to KootK's but the L2.5 is welded directly to the stinger). Not something I like, but he has done it that way for years and has submitted many calculations proving that it works.

As others have mentioned, getting a tread to work in a C8 would be difficult. That's why most stairs are C10's and C12's, but if the detailing works, and the sections size works I don't see any problems with using a C8 (I always feel odd sizing a MC12x14.3 on a stair that is 3' long).

 

[delagina]

Thanks. This is for industrial purpose. There's only 2 civil in my new company so we don't really have good standard. I sometimes use go-by drawings from previous projects. You were right about C8 stringer. My previous company uses C10. Don't know how C8 was working for my new company because they have always used that for miscellaneous platform as well as the L2.5 beam