Segmental retaining wall remediation 1

[ChipB]

I have an upcoming project where the face of the CMU in a segmental retaining wall has degraded. In one section, you can see the interlocking pin for the CMU and the gravel is slightly coming through.

I suspect the freeze\thaw cycles as the main culprit in the degradation of the materials. The geogrid fabric appears to be intact in the location where the degradation has occurred. The wall appears to be approximately nine feet in height at its max.

My first thought is to pull the caps, and grout the cells with a highly flowable grout. The gravel inside of the cells would act as the aggregate, so basically, they would have a concrete wall, stabilized by the geogrid fabric.

Do you guys think this is feasible?

Have any of you come across this before, and if so, how did you address it?

Thanks in advance.

ChipB

 

[BAretired]

What height of fill is it retaining?

 

[ChipB]

Approximately 9 feet at the highest.
Supporting a parking lot.

 

[JedClampett]

It's not time to panic, but you might put it on your schedule.
I see some of the backfill washing out of the hole in the wall. That means a void could be forming behind the wall, with loss of support for the backfill. If you're not an expert on these, you might want to call in one.
We have a Geotechnical Company local office that gives lessons learned lunch and learns on occasion. It's a free lunch and PDH, I try to attend. It seems that for every three Geotechnical Failures, one is a segmental wall. They're (the failures) usually not designed correctly, but sometimes other issues (bad installations; unskilled labor) cause the problem. The failures aren't usually life threatening, but they are ugly. I'd tread lightly.

 

[ChipB]

BAretired and JedClampett,
Thanks! You guys are always great!

 

[Jrit]

I don't have much experience with flowable grout, but 9 feet of drainage aggregate, grid and block seems like a lot to flow through. And, you don't know how much soil has washed into the crushed stone. Depending on the extent of the damage, maybe some formwork and grout from the bottom, possibly in multiple lifts (not the entire wall face). Probably not a solution to the underlying problem, though.

 

[WARose]

Chip, how goes it? You still with the same company you were with back in 2014? (You and I worked together at that point.) Still coming into the Greenville office?

 

[ChipB]

Still with the same company. Just changed names/owners.
In Greenville 3 days/wk.
Remote the other 2 days.