Hole knocked in basement retaining wall

[akamike]

Several years ago, contractors installed a new pipe through an existing 8" basement retaining wall (height = 7.5' above floor slab). They excavated behind the wall, knocked out a 24" diameter hole near the base of the wall (above slab), placed the 12" diameter pipe through the hole, placed some plywood chunks around the pipe on the soil side, then backfilled.

Obviously not a high-quality job, but seems to have caused no problems other than some water intrusion during heavy rain. Should this be fixed? Owner may argue that it has performed fine for several years. (The structure is 57 years old and no drawings are available, so unsure about rebar.)

 

[TPNY]

Is it a bearing wall for floor joists, or do they run in the other direction? Look above the hole and see if a joist sets directly above or nearby. Also, the base of the wall is where you see the largest soil lateral loads, but assuming no rebar was cut during the creation of the hole, you may still have adequate lateral and longitudinal rebar (if any was installed in the first place) to support the loads.
Granted, nothing has happened to date, I would be concerned about the water infiltration for livibility and health reasons.

 

[akamike]

Zo40, thanks for your reply.

The floor joists run parallel to this wall so, no, it's not a bearing wall. I suppose that's good on one hand because not too much gravity load needs to be redistributed, but not good on the other hand because there's very little lateral restraint at the top.

I didn't see evidence of cut rebar, so it might be spaced far apart or not there (or it was there but I just didn't see it).

I'm not a big fan of the water infiltration, either, but it appears the wall has held up under "proof loading" and therefore I don't have much of a structural argument for repair. (?)

 

[SperlingPE]

If the assumed plain concrete can transfer the shear load to either side of the hole and there are no signs of distress around the hole I would be inclined to not fix it. However, I think you have a responsibility to alert the owner to this situation and any possible problems if it is not fixed.