Add a balcony supported by braces to an existing metal structure

[teryos]

Hello,
Hello, I wish to add a balcony supported by braces to an existing metal structure. I would like to know how to proceed to justify that the beam and posts of the existing structure, which support the loads of the balcony, safely withstand the loads in both cases, whether we have the calculation note of the existing structure or not. Thank you all in advance.

 

[hokie66]

A structural engineer is what you need. No one here can even attempt to answer you with such limited information.

 

[teryos]

Thank you for your reply. It's not about carrying it out myself, but rather about learning how seasoned engineers proceed (the experts' thinking) to conduct this type of study.

 

[canwesteng]

Determine the loads, determine the internal forces in the members, then check those against their strength.

 

[JStephen]

I am reminded of the Dilbert comic where the boss tells Dilbert "You should analyze the problem and then solve it."
Anyway, add to the above:
Determine properties, details, and design criteria of existing structure. If there are no existing plans or calcs, that may be involved in itself.
Determine applicable codes and regulations for the modification. That might include access/safety, etc.

 

[XR250]

I mean, isn't this what they teach y'all in school. If not, maybe you should not be taking on this project.

 

[LittleInch]

The people in the floor below aren't going to like a beam across their window....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[teryos]

Thank you for your answers. I would just like to get an idea is it necessary to redo the calculation of the entire existing structure including the balcony or is there a method to justify that the beam and the 2 columns of the existing structure resist.

 

[Tomfh]

It is impossible to say with so little information. You may as well be asking your dentist how much work you need done, before he's even looked inside your mouth.

 

[JStephen]

This article has some discussion on the issues:

https://www.structuremag.org/?p=17307

 

[SWComposites]

teroys,
It HIGHLY depends on,
- the size of the balcony and the loads on it, and
- the robustness of the existing structure
So, thinking is required, along with a lot more info, before an analysis plan can be devised. There is no simple one method fits all answer.

 

[lexpatrie]

The majority of the existing structure is not affected, so typically those are allowed to be left in place and the engineer only looks at the existing loads, the affected existing structure, and designing the necessary components that are being added and the loads required. It would be unusual to perform a full structural analysis of the existing due to adding a balcony (I suppose there are wind/seismic loads potentially, but they are fairly likely to be not of that much consequence) and somewhere on the load path, the average engineer would probably stop checking elements, so the foundation might not be explicitly checked, for example.

 

[LittleInch]

Just the two columns and the cross beam being analysed is quite conservative but if it works then you would be fine.

As soon as you need to include other elements to avoid excessive bending or forces then it gets more complex.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[teryos]

Thank you for your reply.