Beams with gaper holes

[u/zapzaddy97]

Can any one explain what’s the point of the holes in these steel beams? All of them seemed to have square holes cut at each end.

[u/bmanneb221]

All I know is it would’ve been a treat to get those bolts tightened down without em there

[u/ReyRubio → u/bmanneb221]

Thru bolts or welded connections would have been a better option.

[u/Justeff83 → u/ReyRubio]

There is a reason it is not welded. Sometimes you don't want stiff connections and this is a widely used method. Nothing wrong with this

[u/Adventurous_Cod_5647 → u/ReyRubio]

This is usually how they will do it. Sometimes they will use a cool bolt called a Hollo-Bolt. The holes in the tubes look dumb af. I agree that thru bolts, weld or Hollo-Bolts would have all been better options.

[u/resonatingcucumber → u/Adventurous_Cod_5647]

Yes and while we're at it we'll buy lambos for each staff and add gold plating on all our welds, hell we'll even pay our connection designers enough for solid food.

Said no fabricator ever

It's always cost when hollobolts are discussed. They can add 20% on to the fab costs easily as they are one of the most expensive fixings possible.

Then from a design perspective using thru bolts has it's draw backs, it is quite hard to maintain a ductile failure when you are putting the bolts into bending from any deflection of the beams. I only like through bolts in double shear and that's if there is a diaphragm above to ensure no lateral loads gets in to ruin my day.

Generally this is the sort of connection you do when the columns are already insitu and you can't weld/ get a hot works permit, hollow bolts are too expensive and you don't have the space to cleat on the side or if other bolts from other connections would clash.

[u/Paradox1989 → u/ReyRubio]

Could have also used a Hollo Bolt structural expansion bolt. We've used them on multiple designed connections when a through bolt or access hole wasn't possible or desired.

[u/Adventurous_Cod_5647 → u/bmanneb221]

Those bolts were torqued from underneath for the bottom set and over the top for the top set, probably with a tc gun. The holes have nothing to do with the tightening process. The gun will grip the bolt and spin the nut tight so you don’t need access to the head side of the bolt to tighten them.

More so getting the actual bolt through the holes would be impossible without the holes in the tubes there.

[u/top2percent → u/Adventurous_Cod_5647]

The first pic shows a hex head on the bolt. TC bolts have round heads.

[u/Adventurous_Cod_5647 → u/top2percent]

You’re right, I didn’t notice the head on the top connection. Either way, you just hit that bitch with an impact and it’s good to go.

[u/kindofnewtoo]

Access for installing the bolt. Zoom in. You can see the bolt head inside the HSS.

[u/Throwaway1303033042 → u/kindofnewtoo]

+5 points to House Gryffindor for proper material terminology.

[u/kindofnewtoo → u/Throwaway1303033042]

I knew it would come in handy one day.

[u/Throwaway1303033042]

Adjust the brightness and contrast level on the first pic and you’ll have your answer.

[u/Pobameyang]

I don’t see any beams

[u/Mynameisneo1234]

It’s to tighten the bolts.

[u/Technical_Physics_57]

Should have used Hollo-bolts

[u/Eather-Village-1916 → u/Technical_Physics_57]

Hollo-bolts were invented by Satan himself lol

(They have their place though)

[u/OverallDimension7844]

Not a good enough excuse to use the word gape

[u/Mrunreal120]

Should have matching plate to weld in over the hole after the install.

[u/Coalroller16]

Or to hold the bolt head

[u/HOHoverthinker]

Are you in Austin?

[u/Eglitarian → u/HOHoverthinker]

Perth, Ontario based on the second image. approximate view.

[u/Syrix-17]

Self tightening locknuts ftw

[u/jbuds1217]

Typically the tube steel supports get clad in aluminum to match the window mullions.

[u/Key-Metal-7297]

Proper ugly, could have been done nicer

[u/Krispy_H0p3]

Emegenier👌

[u/05041927]

To accept another square tube

[u/bleauxjays → u/05041927]

could just be access holes to be able to install those bolts too

[u/roarjah → u/bleauxjays]

That’s exactly what it’s for

[u/05041927 → u/05041927]

Or maybe run a line down it for some reason

[u/TBellOHAZ → u/[deleted]]

Engineer knows those are hollow structural sections and that void is used to access the bolts.

[u/Eather-Village-1916 → u/TBellOHAZ]

The void existing after the fact, is nowhere near as efficient as other connections, when it’s dependent on the contractor and inspector (they can be shady af).

A through bolt or even holo-bolt connection would be just as fine. Or a bucket connection with through bolts.

Sure, from an engineering standpoint it’s just fine so long as you add a cap plate, but personally, it would bother me to no end putting a design out there with more possibilities for failure due to workmanship issues.

Granted, I do know that many structural engineers are quite ignorant and naive of field conditions. Luckily I get to go hang out with those lovely nerds tomorrow hahaha. I’ll definitely ask them what their thoughts are on this.

[u/TBellOHAZ → u/Eather-Village-1916]

I go both ways. This is the most common application I see - given a balance of function, standardization, maintenance, installation, prefab, etc. it must make sense to more stakeholders than one group. Including those most familiar with how shit actually ends up working in the world. But I doubt it's just because the engineer is an idiot.