Steel packout at point load

[Buleeek]

Hello everyone,
I have a packed out steel girder that is going to support an lvl beam with 10 kips point load. It will be a flush connection. What do you recommend checking in such situation ? I figured I would install 3-4 bolts on each side and calculate for shear between steel web and wood pack out.

Thanks,

 

[XR250]

How are you going to deal with the eccentricity on the packout and torsion on the beam?

 

[BAretired]

Good question, XR250. The lvl beam must be connected to resist the eccentric moment.

 

[phamENG]

At 10kips, I'd probably not use wood to pack it out. I'd want a steel web stiffener in there that will also support the top flange and use a welded top flange hanger for the LVL. Torsion on the girder needs to be checked as XR and BA said. I disagree that the LVL connection needs to resist it, at least as long as the steel beam is sufficiently stiff in torsion to resist twisting.

 

[XR250]

I usually have them fab a saddle and then use a long plate bolted to the side of the LVL to react the torsion. I have not had much luck with a torsion calc panning out - especially considering the bearings are probably sans attachment to the structure.

 

[Buleeek]

Sorry for late response. Usually I do blocking (if possible) on the other side to engage other members in resisting torsion.

I have a question regarding bolt spacing and amount in wood - wood connection. See attached. Simpson only provides information regarding two screws, and I want more. The NDS is vague about it too. I calculate the C-factors but I still want to make sure there are no other limitation regarding the bolts carrying the load P.
Thanks,

 

[gte447f]

Buleeek, what's the point of the "pack out" if you are using a top flange hanger?

 

[phamENG]

For this you need to look at the LVL supplier's literature. They all have details on multi-ply fastening at point loads.

 

[Chessanyone]

I typically plate the WF on one side to create a closed section to address the torsion in such a case.

Is there one connection coming from one side only?

I’m skeptical of having the LVL connection take the torsion. The reality is the rotational stiffness of the moment connection at the end of the LVL is not likely to be stiff enough to prevent rotation. So even if it has the capacity, it’s going to allow rotation of the girder. I suppose you can consider that compatibility torsion and not equilibrium torsion. I would try to modify the section to address the torsion.

 

[Flotsam7018]

You may be able to create a direct bearing condition on the bottom flange depending on the geometry, NDS allows a 2/5 max depth compression notch at the ends but I'd also check with the manufacturer and verify the reduced shear capacity.

If you've got a nailer on the top flange and other framing members along the length of the beam I'd say it's restrained against torsion - else you could provide blocking at a sufficient spacing to adjacent framing members. This may be what you were indicating in your previous post. Else you're probably stuck with the AISC DG9 checks or if the top flange hanger works and the eccentricity is similar to a typical shear web connection, the torsion could likely be ignored.