Freestanding wall with footing on one side only
Freestanding wall with footing on one side only
(OP)
Hi, All!
I have to design a brick masonry freestanding wall, with footing on one side only.
The wall will be 15 ft high, above ground level. RC columns shall be provided tentatively at 10 ft on centers, within the wall.
Wind load is to be as per ASCE 7-05 category C, for 100 mph wind. design is to follow US codes.
I want to have some guidance on how to go about it? and, to know about preferable options. Link to some relevant example or sharing of experience by those who already have done something similar, would be appreciated.
Thanks.
I have to design a brick masonry freestanding wall, with footing on one side only.
The wall will be 15 ft high, above ground level. RC columns shall be provided tentatively at 10 ft on centers, within the wall.
Wind load is to be as per ASCE 7-05 category C, for 100 mph wind. design is to follow US codes.
I want to have some guidance on how to go about it? and, to know about preferable options. Link to some relevant example or sharing of experience by those who already have done something similar, would be appreciated.
Thanks.






RE: Freestanding wall with footing on one side only
1) So does the brick span horizontally to the concrete columns?
2) Watch P-delta effects under deflection. Just the self weight of the wall can cause problems. I've had this come up when looking at free-standing CMU fire walls.
3) Pay lots of attention to your concrete detailing at the opening/closing joint between your concrete columns and the footing. Bad things can happen at those free edges.
4) When you get settlement, it's probably not going to be uniform. It will cause the wall to tilt some . It's probably not a big deal but should be considered.
5) Will you locate the footing deep for frost protection? If not, and the wall is long, consider breaking it up into discrete lengths. Frost lenses can develop somewhat locally and cause differential heave along the length of long things.
6) Would a brick faced concrete or CMU wall be more economical? I assume that there's some reason, other than elegance and fearlessness, that's leading you to go all brick.
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Freestanding wall with footing on one side only
Wind blowing toward the footing side is easily handled. Wind blowing away from the footing side requires enough dead weight to balance the wind moment with an appropriate safety factor. This means a rather inefficient foundation design. Alternatively, you could use drilled piles to resist the moment.
BA
RE: Freestanding wall with footing on one side only
Mike McCann, PE, SE (WA)
RE: Freestanding wall with footing on one side only
KootK!
Yes, the brickwork span horizontally to the concrete columns.
Burnt clay brick masonry is cheaper in my current project area. RC columns are for strengthening the brick wall.
BA!
Yes, the wall is on a property line. And, the main reason to go for one-sided footing.
BTW... How do you people design freestanding walls? Using spreadsheets, or some other software?
RE: Freestanding wall with footing on one side only
RE: Freestanding wall with footing on one side only
Somewhat of an "outside-the-box" look at the problem since it results in a "saw-tooth" plan view of the footing... but it will work, should prevent differential settlement, is reasonably constructible.
See the attached sketch.
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RE: Freestanding wall with footing on one side only
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Freestanding wall with footing on one side only
BA
RE: Freestanding wall with footing on one side only
KootK - I suppose you had better remove my original claims from the vault... or at least put an asterisk by it that it can help, but not answer the eccentricity problem.
In the meantime, I'll see if my wife has cooked a "humble pie" for the holidays, so I can have a slice.
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www.VacuumTubeEra.net
RE: Freestanding wall with footing on one side only
BA
RE: Freestanding wall with footing on one side only
RE: Freestanding wall with footing on one side only
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: Freestanding wall with footing on one side only
spats!
Do you have some other idea, in case wall is moved by 6"? I am interested to know that.
RE: Freestanding wall with footing on one side only
@OP: the extra six inches that Spats mentioned will accomplish at least two useful things:
1) It'll improve the peak soil stresses at the edge.
2) It will facilitate better rebar detailing at that all important opening and closing joint (my point #3 above).
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Freestanding wall with footing on one side only
BA
RE: Freestanding wall with footing on one side only
@BA: if the numbers supported it, would you be comfortable with a single line of piles and grade beams beneath the wall? Or would you still want to see outrigger/roll beams? If the outrigger beams were themselves tied down with piles or ground anchors, they could be fairly short.
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Freestanding wall with footing on one side only
I would be comfortable with a single row of piles, but I am guessing that the pile diameter would be greater than the wall thickness, so it would be offset from the centroid of the wall columns; nevertheless, if the pile is big enough, it should be okay.
BA
RE: Freestanding wall with footing on one side only
1. They are "dressed up" to cosmetically look like columns.
2. They are the wall's foundation.
3. They resist the wind load force.
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: Freestanding wall with footing on one side only
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.