retaining structure to Bury a metal building

[boatmon]

schematic design phase for cost budgeting of structural systems.

I am designing a 30x60x18 metal building to be underground (about 1 foot of soil cover)
Trying to estimate soil pressures that may be exerted on sidewall of building along with potential wall structures short of a typical 20' high cast in place reinforced concrete retaining wall around the perimeter.

considering stacking some sand filled containers or am open to suggestions.
I am reasonable sure that I can "beef up' rigid frames or even double them by using a 10' bay and decrease purlin spacing to withhold soil pressures, but have no idea how to roughly figure imposed loads.

Soils reports were good clay/sand sand/clay down to 25 or 30 feet and being on top of a hill, I and pretty sure no underground springs.

Mel

 

[boatmon]

 

[SlideRuleEra]

1) ...design phase for cost budgeting...
Trying to estimate soil pressures that may be exerted on sidewall of building...

2) I am reasonable sure that I can "beef up' rigid frames or even double them by using a 10' bay and decrease purlin spacing to withhold soil pressures, but have no idea how to roughly figure imposed loads.

1) 5500 lb. per linear foot of 18' high wall.
In other words, one 60' long sidewall will have total force on it of 330,000 lb. (60' x 5500 lb/ft).

2) Average load per square foot of wall = 306 lb/ft[sup]2.[/sup].. forget it. Contact a qualified engineer, what will be needed is essentially a cofferdam or braced excavation, not a buried building.

 

[MTSOE]

This is a bad idea. Please contact a structural engineer with experience in underground structures. I do not want to be disrespectful, but I also don't want you to attempt this project as you've described it.

 

[boatmon]

My apologies for throwing up rough sketches without enough info.
My concept is to
excavate,
pour post tension foundation,
place fill soil cement filled tote containers sideways and stack with cement mortar bed like stack bond bricks(with pallet side to retaining wall),
probably pour flowable fill at Botton 5'of fill area against totes,
then backfill remainder with re-compacted soils from excavation.

I don't have any idea of how to estimate lateral loads on whaler wall to estimate sheathing load /spans,
and whaler beams,
with tension cable/ threaded rods,
and helical coils.

I see the structure much like waterfront bulkheads that I have seen much of.

 

[SlideRuleEra]

I see the structure much like waterfront bulkheads that I have seen much of.

Hiring an engineer who is qualified to design waterfront bulkheads is a good place to start.

 

[boatmon]

That is what full intended to do, but I was trying to see if this system would be worth pursuing,
It will make the project go or no-go budget wise.
We have subs capable of doing this without 500 to 750k of sheet pile put into the mix.
Not a govmint job.
Thank you for the input.

 

[MTSOE]

Another option to consider is some type of buried arch structure. I'm not sure where you are located but if you're in the US or Canada, reach out to underground product suppliers like DSI, Jennmar, or Reinforced Earth. Their products are typically not used on habitable structures (unless paired with some other permanent lining) but they might be able to point you in the right direction, or recommend an engineer in your area. They have in-house engineers but would likely shy away from designing an atypical project like this.

 

[boatmon]

We have a metal building supplier that can give us a structure capable of handling the 30' span and 20' bay, and even have the option of reducing rigid frame span to 15', with 5" slab and 1.5 to 2' of soil. (roughly 450dl and approx 30k column load)

Thus the reason that I was trying to design a cost effective retaining wall around the structure.

Thank you all for your consideration. I am trying to learn from your suggestions
I am just thinking in generalities (typical architect) ha ha