Residential Retaining Wall Repair

[pbc825]

I've been contracted to provide repair recommendations for a retaining wall between two residential properties. The retaining wall is constructed from CMU's that are filled with cement or grout. I didn't see any reinforcing steel poking out of the top under the caps. There are no drawings of the wall or the foundation systems for the two neighboring buildings. The highest differential soil height is about 60 inches. The worst angle from plumb is about 10 degrees which coincides with the maximum differential soil height. I'm contracted by the west property owner, and the east property owner is quite upset.

Wall is about 10 years old and recently a contractor compacted soils on the east side for a paving stone walkway.

The east neighbor is unwilling to do or agree to anything useful, so tying the top of the wall, pinning and excavating for a new properly designed cantilever wall, etc. is out of the question. As is doing anything to disturb the east property. The distance between the two building walls is about 8 ft and the eave overhang is about 2 ft. The plan as I've conceived it so far is to twist in screw piles (haven't decided on the spacing or pile details yet) and hammer down segments of steel plate. Complications include:

1. Headroom to the bottom of the eave is about 10 ft, so extensions will be required. Extension connections may interfere with wall plates.
2. I've never recommended this sort of repair before, so I have little experience with the execution of such a project.
3. Not sure if we'll have trouble driving the plates in with such little headroom.

I'm seeking advice on a few things.

A. Does anyone have experience with this sort of challenge with similar constraints? If so, what repair recommendations did you suggest?
B. Has anyone made a screw pile and driven plate wall? If so, what were the execution challenges?

Thank you in advance for any advice or wisdom.

PBC

 

[GeoPaveTraffic]

As stated, no easy answers here and made even worse by the east property owner.

I like the suggestion made early in talking with the insurance companies. I've seen good adjustors work a lot of things out.

Mike Lambert

 

[PEinc]

hokie66, I did look at the photo. It shows the heat pump sitting up in the air on supports. Some fill could be placed under the unit. Also, while we do not know the depth of the basement, it may still be possible to add more fill against the foundation wall, especially if the fill slopes downward to the foundation wall. This would need to be investigated. If necessary, window wells could be used around the basement windows in order to keep the fill off the glass. Not much else is shown in the photo. I have suggested this fill idea so that the OP can, at least, consider a much cheaper option than those presented above. There may be a few "problems" to consider with this fill option, but possibly they can be addressed cheaply.

http://www.PeirceEngineering.com

 

[hokie66]

Basement? How did you decide there is a basement?

 

[jayrod12]

Almost everyone has a basement in Canada,

Before I get ripped for that comment, it might not be everyone but seriously most single family homes have basements. It's a reasonable assumption. and since there are windows showing in the picture then one can only assume there is a basement, otherwise why windows?

 

[PEinc]

I also assumed that there is a basement because of the visible window. If there is not a basement, or if there is only a crawl space, there should be even less concern about filling against the foundation wall.

http://www.PeirceEngineering.com

 

[hokie66]

If that is a window, fine. I thought it might be an underfloor vent. If there is a basement, I would want the wall and the waterproofing investigated, as I think you suggested.

Maybe I should just stay out of Canadian discussions.

 

[dcarr82775]

Is that a structural A/C unit? Strange that the wall seems to curve around it. Whomever built it is responsible for whatever happens.