Need some help with concrete calculations

[Bryanbdp]

Anyone out there have a little time to talk about concrete engineering?
Mostly need to calculate proper rebar amount for loading.
If this is your area of expertise and you're willing to share it would be most appreciated...
Thanks,
Bryan

 

[Old tool guy]

Need a few more details. Slab, foundation footing, column pier. Size.

 

[ConCretin]

The engineering you are looking for would only be necessary for structural elements. Rebar in most residential slabs and foundations is more about crack restraint rather than loading. Whataya building?

 

[Old tool guy]

Bryan, you sent me a lengthy Pm with pictures. That needs to be posted here.

 

[Bryanbdp]

These drawings give some idea of what I'm working on. Existing house on left, new addition on right.
Includes "root cellar" as shown.
Pretty good with walls at 10in thick.
Ceiling should be ok at 12 in thick with the right rebar reinforcement.
Thinking about casting a beam as shown for additional support, since I have room in the packed earth area.
Would like to design ceiling to withstand dead load plus 1 atmosphere of shock loading.
New area is 16 ft x 22 ft OD.

 

[Bryanbdp]

Here is a design example from Swiss guidelines.

 

[wssix99]

This is what architects and engineers are for. For a project like this, you need to find local ones and pay them. You will save MANY times what you pay them in problems you'll avoid down the road.

For one, putting earth between a concrete cellar ceiling and a structure - this will eventually destroy everything around it. You'd have to find really exotic dirt that won't chemically react with steel/concrete when moisture inevitably gets in. If the aim is to have a bomb shelter, then maybe there is a case for dirt. If the aim is to insulate for temperature, then serviceable conventional insulation is the way to go.

 

[Bryanbdp]

The Swiss guidelines have formulas for most of what I need. I just have to figure out how to apply them.
I may well end up having to hire an engineer.

 

[bluedog225]

Cool project. Absolutely need an engineer. Too many things you can miss.

 

[Bryanbdp]

Here is the entire Swiss guideline. It is a design manual for approved shelter construction.
In other words, shelters have to be built to meet these guidelines.
The Swiss are considered the experts in this field, and they went to a whole lot of trouble to write these guidelines.
There are many other aspects to this project, but the structural ones are what I'm working on now.
Chapter three deals with the engineering requirements for resistance to fire, normal loading, and impact conditions.
Not surprisingly, impact/blast conditions control from a structural point of view.
1 atmosphere of overpressure design is good enough for me. If you're more than a couple miles from center of blast, you're probably OK. They state for a 1 MT event, you're OK at 1.6 miles or further. (page 5)

The engineering largely boils down to how much steel is needed for a given set of conditions and how to place it.

 

[Youngandfree]

Are there any Swiss engineers looking to freelance for you?

 

[zimman]

The Swiss guidelines have formulas for most of what I need. I just have to figure out how to apply them.
I may well end up having to hire an engineer.

I would imagine in the NE you couldn't park a contractors truck on the property without a full set of Engineered Stamped plans, permits and the Pope's blessing. Seriously. You should be talking to a structural engineer.
Zim

 

[JWILLIE1977]

This is what architects and engineers are for. For a project like this, you need to find local ones and pay them. You will save MANY times what you pay them in problems you'll avoid down the road.

This. 1000%

Local engineer familiar with structural codes.
With any luck, he/she will be of Swiss descent.

 

[C-S-H]

Great project. With a ceiling load of about 3000psf and wall transverse load of 2000psf in various combinations plus earth forces, this is a 3D design. I would design this room as 6 slabs using plastic design like they are using in the Swiss guidebook. Some of the walls will have large openings requiring a different design.

The Swiss guidebook is quite good, but I do not how someone other than a structural engineer could interpret it correctly. For instance your calculation does not include the shock force, you are not doing plastic design, and your section property calculation is incorrect. Also, your corrugated pans eliminate the wall to ceiling moment connection, and tiny footings eliminate wall to floor slab moment connection. What are the soil and slope conditions?, etc... You should hire an engineer with a CT PE license. It is not a difficult or time consuming design.

 

[Bryanbdp]

Yah, thanks for the input. I was trying to work out the basics but I keep getting lost in the calcs.
Those prints aren't meant to be final but to explain the concept.
Culvert is shown for elevation, it will actually be on an end wall, with a sealed blast door.