Pressure Treated Wood Sill Plate Point Load Dist. 1

[dursunlutfu]

Hi,

I have a wood column inside of a wall carrying a beam supporting a shear wall. Due to the overturning, I have almost around 10kips coming to the sill plate. I was wondering how I should analyze the distribution of the point load over the continuous sill plate which is also taking minimal point loads from the wall studs. Also, can I assume the footing as a rectangular footing and distribute the load for example for 16" width x 48" length. Do you guys think that approach is logical ?

Thank you for your time,

 

[smb_PE]

What is your foundation under this wall? What seismic design category is your project?

Assuming the wall is supported on its own continuous footing or thickened slab, I treat the stud wall like a uniform line load. Depending on the magnitude of the post load, you can either justify that the continuous footing has enough capacity, or specify a spread footing under the post.

 

[WARose]

I'm not sure what you are checking.....but as far as the sill plate is concerned, it's just localized there.

But for anything under that....for a single post.... I'd just spread it out at a 30-45 degree angle.

 

[dursunlutfu]

I was planning to have a short stem wall for the crawl space, and a continuous footing underneath the wall and the post which will be inside of the stud wall. The seismic design category is D.
I am just not sure how to justify that the point load will be distributed along the pressure treated sill plate and how far.

 

[smb_PE]

I guess I didn't understand your original question. Why do you need to justify the sill plate is distributing the post load?

What if you assume the sill does not distribute the load and the load from the post is over an area equivalent to the post size? I'm sure there is an adequate area for concrete bearing if the post size is sufficient for sill plate crushing.

 

[msquared48]

Compared to the concrete stem wall, the plate has little effect on spreading out the load.

Take a 30 to 45 degree line from the base of the column edges to the bottom of the strip footing to determine the unreinforced spread distance. The bottom steel of the strip footing will increase this distance.

Mike McCann, PE, SE (WA)

 

[dursunlutfu]

Thank you so much all! It is all clear now!