Glass bearing

[amwc]

Hi I am looking at a glass roof frameless construction and I was just wondering about the bearing as 1 roof section meets the joining roof section and the supporting glass beam below. The glass beam is 30 mm wide so each roof section will have around 12 mm bearing, all connected using silicone. Does this situation sound correct ?

Thanks in advance

Andy

 

[phamENG]

A glass beam and silicone connections? No. Nothing about that sounds correct at all. Can you provide a little more information? Is this a proprietary system?

 

[amwc]

Hi
It’s a frameless glass box structure with glass walls, fins, beams and roof 1200 mm span onto the beam. Laminated glass - 3 sheets of 10 mm toughened glass
Andy

 

[dhengr]

Amwc:
That doesn’t sound like a beam to me. That sounds like a butt splice reinforcing plate, spanning in the same long direction as the main sheets of glass. And, you have to hold that joint together, unmoving, during the curing time. I would want some sort of spacers, maybe small glass beads or small clear silicone spacer blocks, btwn. the pieces at regular intervals, so I got a continuous 1/8” or 3/16” thick bond joint thickness. You want that joint to act (and be) fairly uniformly over its width and length, so the shear, tensile stress and compressibility, and the like, is fairly uniform over the whole joint.

As PhamENG suggests, we can’t see it from here. Show use some meaningful engineering sketches so we have an idea what you are trying to do. Don’t forget dimensions, thicknesses, span lengths, loadings, support systems, etc.

 

[amwc]

The attached image is what I am trying to achieve

We definitely call it a beam here

It’s 3000 mm long, as said roof glass is 1200 mm c/c 30 mm wide beam 300 mm deep

Andy

 

[dik]

Looks like a beam... to design it, it would be a matter of researching some structural glass design... I've seen this type of construction used for 30' high windows reinforced using glass 'counterforts'. I've never looked into the design, though...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[phamENG]

That's pretty nifty - and completely new to me. Hopefully somebody has some insight - I wouldn't mind learning a little about it, too.

 

[dik]

There is/was a building in downtown Toronto about 25 years back... that had a glazing wall about 30' tall with vertical glazing members providing the lateral restraint... I don't recall what the building was, but it looked great... and glazing adhesive appeared to be clear silicone. I should have paid more attention to it.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[klaus.]

We do thinks like that...currently also in Toronto at The Well project
But you need special knowledge in engineering and manufacturing and erection for such structures....

 

[KootK]

1) The term "bearing" may be causing some confusion here. With glass, you generally want to avoid contact with hard / rough surfaces that would create stress concentrations. So, while this will be a connection upon which the supported glass panels "bear", I would certainly expect no direct, glass to glass bearing.

2) You mentioned silicone so this is probably an SSG connection where the supported glass is really bearing upon the silicone which then bears upon the beam. As you probably know, glass is wickedly strong other than the terrifying brittle fracture stuff. So anything resembling bearing stress is unlikely to be a problem so long as you've got the silicone in play to smooth out the rough spots.

3) If there's something to worry about at this bearing connection, if may simply be the available bearing length. Glass panels are often designed to flex a fair bit and, therefore, draw in at the ends. You may want to convince yourself that the supported glass panels may not loose purchase at the ends with 12 mm of bearing under ultimate load conditions. Locally applicable glass standards may have something to say about this as well. Proper design of your SSG joint may well make this a moot point, it's difficult to say.

 

[klaus.]

In Germany we have a glass design code which deals with glass Structures ...
Maybe you can find an English copy of this codes somewhere.....