"bolt boxes" can't find any data.

[tistas2]

Dear Engineers,

How called this connection type? I saw it in the Arup magazine, they call it "bolt boxes" but there are no other references on the internet. There should be some other term, I suppose.

Thus I can’t find any references about the principle of its design.

 

[bridgebuster]

A gusset-less splice. I suppose in theory it works the same or similar to a pipe flange splice.

 

[KootK]

I think that the dominant feature of the connection is the ability to pre-stress the bolts. So maybe pre-stressed splice? No matter what you call it, it's a pretty unconventional connection and suspect that you'll have a hard time finding published design guidance. Hopefully I'm wrong about that.

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.

 

[Ingenuity]

As KootK suggested, these are prestressed bolt/bar splices.

In the following link/article ARUP used 76mm dia pretensioned bars to achieve the splice.

Link

 

[TLHS]

I get it, and I've used it for base connections where I want to ensure bolt yield for seismics, but it scares me for gravity load shear transfer in those beams (Ingenuity's first picture). In a normal slip critical connection you can fall back on bearing if something happens. In this, if you have a tensioning issue you appear to lose your shear load path and your bolts end up in bending. They'd probably end up deflecting into something approximating the shear friction model we use for concrete, but it worries me.

If I needed to use this, I'd have someone standing there staring at every second of that installation.

The tension and truss members are a different story.

 

[KootK]

Do the bolts not pass through normal bolt holes at the mated plates? I'd assumed that, if you lost the prestressing, it would essentially morph into something akin to a conventional extended end plate connection.

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.