Unable to obtain existing foundation drawings

[Forgot2Yield]

Hi there,
I would like to know peoples opinion in this scenario, and what course of action would be taken:
A client wants you to design a re-build of some old chain decks that are in bad shape. They want to re-use existing columns and foundations, but replace everything else. No existing foundation drawings are available. I have a sense that even though this equipment has been running for however long and is not being rebuilt to be used in any other way other than it's original purpose, it is still not proper to stamp a re-design without knowing what the foundations look like. Is one able to add notes into their drawing excluding them from any responsibility of ensuring that existing foundations are designed properly? Something like "this design ... excludes foundations ... it is recommended to have existing foundations verified before implementing" and put the responsibility on the client if they don't want to pay for a massive job of trying to determine existing foundations?

 

[ANE91]

1. Dig a small test pit.
2. Submit a Freedom of Information Act Request to the AHJ for drawings. Idk what a chain deck is, but if this is anything more substantial than a residence, then there likely exists drawings on file with the AHJ, assuming the building isn’t 100 years old.

Don’t think you can delimit your scope to exclude foundation. Others have different opinions…

 

[Forgot2Yield]

This is for an industrial wood processing facility. I should actually refer to the piece of equipment as a log deck. Logs are transported into the facility via chain runs on these decks. These facilities are typically built outside city limits and so usually no building permits are obtained and therefore no existing drawings.

 

[RPGs]

Is there an option to GPR scan the existing footings?

 

[jerseyshore]

I'm sure we all write "existing foundations to be VIF prior to construction" or something along those lines weekly. Do they ever actually VIF. Rarely.

Each project is different so sometimes the note is all that is needed. Sometimes you put a minimum size on there. Sometimes you may need them to dig 1 test pit. Or 2. Or 3. Maybe a soil test and geotech report.

If something goes wrong the note might get you off Scott free. Or maybe you get sued to oblivion. That's the engineering judgement and how much the risk vs reward is.

 

[milkshakelake]

I don't believe it's proper to put things on foundations without knowing anything about them. It's also not right to put a VIF note, because it will never get done. Has anyone ever followed through with a VIF? I'm not too concerned about the legal aspect (which is a concern others have noted) just because I'm that way personally, but it's still an ethical thing.

 

[azcats]

I have different thoughts on this depending on the use of the foundations. If they're primarily/only vertically loaded and the expected use is the same, I'd be more lenient than if they're part of some lateral system for a load they likely have not yet seen in their lifetime.

 

[canwesteng]

I'm with azcats, equipment foundations with no signs of distress where the load is unchanged aren't a concern. Especially if you are doing replace in kind for the structure, it's not clear how this is different than any structural repair, where we don't usually analyse more than the area being repaired.

 

[Forgot2Yield]

Thanks for all the opinions. RPGs I haven’t had any kind of experience with ground penetrating radar. The area under the deck is all slab on grade, with foundations who knows how far down beneath the slab, so I’m not quite sure of the capabilities. I feel like there isn’t that much risk involved in this particular scenario, but just the idea of stamping something without knowing the complete structure is what doesn’t feel right to me so I would probably opt for adding in the note to be transparent.

 

[dik]

Submit a Freedom of Information Act Request to the AHJ for drawings.

Is that required? In these environs if you have authorisation from the owner, the city will provide you with all the drawing information it has on file... sometimes great and sometimes not so great.

 

[canwesteng]

Thanks for all the opinions. RPGs I haven’t had any kind of experience with ground penetrating radar. The area under the deck is all slab on grade, with foundations who knows how far down beneath the slab, so I’m not quite sure of the capabilities. I feel like there isn’t that much risk involved in this particular scenario, but just the idea of stamping something without knowing the complete structure is what doesn’t feel right to me so I would probably opt for adding in the note to be transparent.

GPR may struggle. It should easily catch any rebar in the footing, provided you can roughly provide the depth, but if you have no bar getting good info through an existing slab is a challenge IME.