Steel Deck cross bracing help

[Spacket]

Hi everyone,

 

I'm trying to put together a set, and I require a steel deck structure which allows me to move a smaller one into it during the show. So basically, is it safe to cross brace on 3 sides? it is likely to have up to 4 people on it during the show. If so, do I have the most logical config?

 

Any thoughts would be much appreciated! Id rather not have a collapsing stage!

 

http://imgur.com/hPvxoEJ

 

 

Thanks!

[J Pearce]

Seeing as you can do 4' with no bracing, I'd personally have little issue using that config, though I'd probably use steel legs for extra stiffness, and look into stopping the front legs moving at the bottom by sitting them in a keeclamp base screwed into the stage (this also stops the whole structure going wandering, which can be an issue when you single bits of deck on their own.

 

I am just another voice on the internet though (and not a structural engineer), so if you do it and it collapses it's your own problem!

[Spacket]

Thanks a lot, ill look into it!

I as going off the same thinking, its just that strange over 4' mark where SteelDeck put the fear of god in your heart about cross bracing!

Seeing as you can do 4' with no bracing, I'd personally have little issue using that config, though I'd probably use steel legs for extra stiffness, and look into stopping the front legs moving at the bottom by sitting them in a keeclamp base screwed into the stage (this also stops the whole structure going wandering, which can be an issue when you single bits of deck on their own.

 

I am just another voice on the internet though (and not a structural engineer), so if you do it and it collapses it's your own problem!

 

 

 

[J Pearce]

It's not strange really, once the height exceeds the width of the deck at the short end the horizontal component of the force presented to the legs in the same axis as the short end becomes far more significant. A little bit of resolving forces, or even scale models with paper straws will show this to be true.

[kerry davies]

If you have never seen a stage "walk" then perhaps

involved? Tie the feet together and it goes nowhere. There is also the small factor that once a tube, even in steel, gets above four feet in length it becomes fairly easy to bend, try it!

 

Your weak point is the open front so it depends on both loads and dynamics whether the front legs would splay or not.

[ontoprigger]

Are you getting the deck supplied? if so then it will be down to the supplier to do the maths and tell you if its possible, if you own the deck then its down to you to do the maths, but you must follow the manufacturers guidance in its design.

 

Having said that I have done many decks and scaffolds with one side open, as long as the feet are fixed to the stage and there is suitable bracing on the other sides there should be no problem, you may need a horizontal tie on the non open sides 150-200mm from the floor, also if you have access stairs these can add bracing to the structure if in the correct plane. You do need to seek the advice and guidance of someone who understands designing and building these structures and has the suitable liability.

 

Also you are going to find that the fit up of this will more than likely come under the CDM regulations so if your not the principal designer then it may be worth discussing the requirements with whoever is.