Wind Force on a Braced Frame Footing
Wind Force on a Braced Frame Footing
(OP)
I'm designing a footing for a 1 story building with interior braced frames and 4 shear walls at the exterior. With wind calculated from MWFRS, I have determined the wind force, at the roof level, for the braced frame (taking half of the total wind, because half is transferred to the ground). My question is: when designing the footings for the braced frame, would you only design for the lateral force from the braced frame model (i.e. only half of the total height wind force on the building), or does a slab on grade transfer the other half of the wind to the braced frame somehow? Or would you design the interior footings for half of the height wind load and then design the wall footings, which actually take the wind pressure, for that other half? Thanks.






RE: Wind Force on a Braced Frame Footing
Often you're dumping the load into the foundations at the bottom of the wall that you're looking at and running parallel to the wall that you're looking at. From there, it might be passive soil resistance against a frost wall or friction between the soil and the SOG. Frankly, in many instances, I think that this aspect of load path gets ignored altogether. And a lot of times that's fine. It's good that you're at least contemplating the load path though.
If your building is collecting these loads through girts and then delivering them locally as column base shears, then the path may warrant greater consideration with hairpins etc.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.