PEMB continuous footing to resist sliding

[cec17]

See below. In a traditional PEMB with perimeter column footings, do you ever consider the continuous footings to aid in sliding resistance? It's not something I have done, usually I design the column footing isolated to resist overturning and sliding, or hairpin to the slab for sliding resistance. I see no mention in Newman of using some portion of an adjacent continuous wall footing to resist sliding, not sure how that would be quantified (using the whole trib width?). Just wondering if this is something that others have considered as I can't see any reference to it.

 

[DaveAtkins]

I think it could be an acceptable load path, so long as you check lateral bending, shear, development, etc.

DaveAtkins

 

[canwesteng]

Does shear even need to transfer for sliding resistance? If you use friction with the soil, you just need to transfer vertical loads.

 

[dflva]

I have designed foundations for a handful of PEMB projects. I have not considered the continuous footings adjacent to the spread footing in resisting sliding, but I agree there is some legitimate amount of contribution. Determining a reasonable limit on the effective length of footing is a tough problem. I can say halfway to the next column is too much. I do like the stem wall tying everything together. Also remember that some amount of the wind load on wall (bottom half?, consider girt spacing) is resisted directly by the continuous footing and could be in the same direction as the D+L+W thrust.

 

[johnwow]

I do PEMB foundations regularly. I have a design to handle most building sizes where we use continuous footings to transfer all loads rather than isolated spread footings. The size of these isolated footings are wild considering the first thing that's going fly off on these tin cans is the metal roof. We do still add in hairpins for thrust.