Wall bracing for failing CMU 2

[SteveMinVT]

This is a residential building, wood framed on a CMU foundation that is below grade. It has already been determined that cracking in areas of the CMU is due to the foundation wall being inadequate to hold lateral soil pressure from the outside. We plan to solve it use bracing of the type as shown in the attached picture.

What I am looking for is general rule of thumb for sizing the posts (tube dimension, metal thickness) and their spacing relative to one another.

-SteveMinVT

 

[MiketheEngineer]

No rule of thumb---

1. Get rid of any water - drains, pumps, etc.
2. Get rid of any plastic clays
3. Determine soil load.
4. Proceed with design

This is ONLY one of a few ways to solve this problem and probably one of the ugliest...but works quite well - usually.

 

[ztengguy]

wouldnt it just fall under steel design for a beam, since there is no axial load. Spacing determined on how far the cmu could span unreinforced? Generally I have never seen these do anything but bend with the wall.

 

[SteveMinVT]

thanks Mike and Zteng...

But I am not an engineer, just a stone mason. So the loads I am happy to calculate if I knew the algorithms to use.

Soil is basically 7ft high on the exterior side.

I plan to excavate along the perimeter (2 ft wide) down to the footing. Install drain tile, and drainage stone for the entire cutout and encapsulate the whole thing in a spun geo-fabric. And there an addition going on adjacent that will tremendously with drainage.

The help I need is with the interior "design" of the posts, in other words spacing of the posts and size and type of posts.

thanks, Steve

 

[MiketheEngineer]

Sorry - call a local structural engineer who can analyze exactly what is going on.

Remote engineering is not only dangerous - but may be illegal in most states...

These forums are just for "bouncing" ideas off of others. Actual defined answers are seldom offered.. and for good reason.

 

[SteveMinVT]

Ah, thanks Mike. I never picked up the subtlety of general ideas, versus specifics - and wasn't dialed into the liability issue at all. Nonetheless, still a good forum. -Steve