Hollow section expansion bolt 1

[Ramezsayed EIT]

Hey

I am designing a connection of cantilever beam with end plate connected to HSS Beam. The customer doesn't want to weld the end plate to the beam so I proposed the HSS expansion bolts

it seems that these bolts are very expensive so they came back to me asking for different type of connection. Is there any other option that I don't know ?

Ultimate tensile load / bolt = 4400 lbs
Ultimate Shear / bolt = 390 lbs

 

[Tmoose]

How far is the cantilever beam from the end of the HSS "beam" ( column ?).
I'm thinking maybe a "nut plate" could be fed down into HSS "beam" ( column ).
Could a nice thick plate be welded to the outside of the HSS "beam" ( column ?) and holes drilled and tapped for standard fasteners?

 

[dauwerda]

I have seen through-bolts used with sleeves installed on the HSS, although I imagine that would cost just as much if not more than the Hollo-Bolts. You could have a beam stub welded directly to the HSS, moving the bolted end plate connection away from the face of the HSS. Flow drilling is another option with HSS - I'm not sure how the cost of that compares to a Hollo-Bolt.

 

[JLNJ]

Small cantilever? Shop weld.

Tell us the geometry and we can provide better suggestions.

 

[Ramezsayed EIT]

The cantilever is 60" projected (cantilevered canopy outriggers)
spacing = 48"
cantilever HSS 3" x 1/2" x 1/4"
End plate fillet welded at the end of HSS 8" x 6" x 3/4"
Main HSS Beam is 12" x 6" x 3/8”


Main beam is existing and the outriggers will be fabricated in the warehouse.

 

[GC_Hopi]

Shop weld a beam stub or plate to the HSS that will give you something to bolt to.

 

[Agent666]

One thing to keep in mind as well regarding the lindapter type hollo bolts if you go down that route is that the actual external diameter/size is quite a bit larger than the nominal diameter/size due to the sleeved design.

It can take out quite a bit of your column section if you get into the larger sizes which potentially needs some assessment.

The other thing is that they require a hole tolerance much tighter than the typical 2mm oversized hole for a typical structural bolt. Something like 1/2 a millimeter from memory (go look at the suppliers documentation though to confirm).

Propose no canopy, that's the cheapest option for those types of clients who take offense at pretty much everything logical.

 

[Eric C.]

Why is your customer objecting to welding the plate to the beam? It would seem that most other options are either more costly or more time consuming (way more costly).

 

[MIStructE_IRE]

Weld will look waay better here! And will likely be a better job anyway.

 

[Retrograde]

I have seen through-bolts used with sleeves installed on the HSS, although I imagine that would cost just as much if not more than the Hollo-Bolts.

In my experience the through bolts with sleeves are significantly cheaper than hollo-bolts. That's the option I would choose.

 

[Tomfh]

In my experience the through bolts with sleeves are significantly cheaper than hollo-bolts

Good strong detail too.

 

[dhengr]

Ramezsayed EIT:
I’m so damn sick and tired of clients asking for stupid, impossible things/details and then insisting that they be cheap, simple and invisible too. But, not your first way, or your second and third ways, etc. etc. Tell them you don’t need those damn canti’s. for your part of the structure, so just note “see Arch.” on your plans, and be done with it. Let them figure it out. They could save a whole bunch of their money by eliminating all the canti’s. Shop weld a very thick pl. to the side of the main beam. Tap this side pl. for the canti. moment end bolts which you need for the end pls. on the canti’s. The side pl. has to be thick enough and of strong enough yield strength so that the tapped depth is enough so the bolt won’t bottom out, and still has sufficient engagement for the bolt loads needed. Don’t forget to check the main beam for the torsion that these canti’s. introduce. If it is only a 60” canti., the main beam can be shop fabed. with the canti’s. welded to the side of the beam. This is a truck deliverable sub-assembly in 30 or 40’ lengths.

 

[Ramezsayed EIT]

dhengr

They are super exhausting!

Designed a welded connection and the came back telling me that they don't have welders on site and they are not willing to hire one
Designed a bolted connection and they told me its expensive option

I actually suggested using stud bolts(nelson stud welding) or bolt with sleeve. Main beam will be designed by others but I provided all of the reactions on it so they can check the design as you mentioned.

Thanks all for your cooperation.

 

[Settingsun]

Is the sleeve loose or welded to the hollow section?

 

[Ron]

I agree with dhengr...sometimes clients are just a pain in the a$$ and have to be told how it needs to be. They want our advice but tend to convince themselves that they know more than we know. Then there's the impossible ones that want everything for nothing....remember, you have three options to give them...fast, cheap and good....they can only have two out of the three.

 

[Agent666]

With most contractors it's one out of three?....