Walkout basement foundation design
Walkout basement foundation design
(OP)
I was asked the other day about a foundation for a walkout basement. I have never designed one before and I don't have to at this point but I would like to be able to design one if I am asked to in the future. Below is an example that I am working through. I have attached a picture to help you understand my text below.
The north, west and east walls will be conc. walls and the south wall will be wood. The floor joists will run north-south and will bear on the north and south walls (there will also be a 2x4 stud wall in the basement that the joists will bear on).
Should the north wall be designed with a cantilevered footing?
Should the east, west and south walls just be typical 8" concrete walls?
I am sure I will have more questions but I will start with this. Thanks.
The north, west and east walls will be conc. walls and the south wall will be wood. The floor joists will run north-south and will bear on the north and south walls (there will also be a 2x4 stud wall in the basement that the joists will bear on).
Should the north wall be designed with a cantilevered footing?
Should the east, west and south walls just be typical 8" concrete walls?
I am sure I will have more questions but I will start with this. Thanks.






RE: Walkout basement foundation design
RE: Walkout basement foundation design
Should solve your problem. And then you don't need a North retaining wall
RE: Walkout basement foundation design
Sometimes, say in a bi-level, the floor is not a continuous diaphragm so you either make the north wall a retaining wall or generate some other lateral resisting elements (interior shear walls running north-south).
Also, if applicable to your location, the south wall foundation has to be carried below the frost line.
BA
RE: Walkout basement foundation design
Mike/BAretired, what are some ways to transmit the shear to the E-W walls?
RE: Walkout basement foundation design
RE: Walkout basement foundation design
RE: Walkout basement foundation design
http://www.bayarearetrofit.com/PDFs/APA%20Research%20Report%20138%20.pdf
RE: Walkout basement foundation design
For your walk-out basement, the diaphragm would be subjected to sustained loading from earth. A lot depends on the layout of the structural walls and openings in the floor.
RE: Walkout basement foundation design
The diaphragm requires chord members on the north and south edge designed to carry wL2/8 where w is the load per unit length from the earth pressure and L is the span.
The diaphragm must be connected to the east and west walls to resist the full shear resulting from the lateral load, namely wL/2 each end.
You really ought to read up on the design of wood diaphragms before embarking on this design.
BA
RE: Walkout basement foundation design
So what I need to do next is to calculate Vcp and Vnp and the deflection as per the pdf SteelPE reference above right?
RE: Walkout basement foundation design
RE: Walkout basement foundation design
Why not extend the concrete up another 12" and hang your joists off of a ledger connected to the concrete?
RE: Walkout basement foundation design