# Concrete retaining wall crack and bowing - How to anchor?



## Canarywood1 (May 5, 2012)

homeowner_101 said:


> I have a concrete retaining wall that was poured at the same time as my foundation. This is for a walk out basement. The wall is around 8 feet tall at the high end (at the house - and it's actually part of the poured foundation of the house...all poured together) and maybe 4.5 feet or so at the lower end away from the house. It's about 15 feet long. It has developed a crack in the center and goes diagonal from top to bottom. If I look closely it seems like the wall is slightly bowed too (very, very slightly). I assume the wet soil over time has put a lot of pressure on the wall and I'm worried that if I don't do something about it, it'll keep getting worse until at some point it would be too bowed to fix it as is and maybe a new wall would have to be put in place. I'd like to stop it well before it gets to that point. The wall is the same thickness and grade of concrete that my home's foundation has. It has a poured concrete footing as well, below frost line per the building standards in 1996.
> 
> Anyway, what is the usual fix for something like this? I was thinking about how they use anchors on old brick buildings to keep the brick walls from bowing out. Could something like that be used (same concept) to secure this wall into the soil so it won't move anymore and stop the crack where it is and no more bowing? For example, it seems like if you were drill holes (maybe anchor it in 3 places) to screw in anchors which have a large auger on one end and a threaded bolt type head on the other end, several feet into the soil (horizontally), that would secure it very well. I don't know how they normally fix things like this, but I'm just thinking out loud. Does such an anchoring system exist for walls like this? I assume a foundation repair company would be the one to do this type of anchoring? I guess I don't need a 'repair' right now. I'd just like to have that wall anchored in so it won't move. I have no idea if this is something that can be done.
> 
> Thoughts?


 

Your probably right about hydrostatic pressure causing the problem in your retaining wall, do you know if drain tile was used behind the wall when it was built, and if any batters or deadman anchors were used.


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## homeowner_101 (Apr 11, 2011)

There's a perforated 4" drain pipe along the wall covered in gravel. It's a continuation of the foundation wall drain. I was looking at the drain today and it's flowing like a stream today due to the saturated soil from rain and snowmelt. 

There are no anchors behind the wall I know of. I was around when the house was built but by the day it was backfilled. I'm sure it's not anchored in any way though. I think it's simply backfilled and that's it. 

I think it's just too high with so much pressure on it and over time, without something holding it back, it has no choice but to give way a little to all that pressure. Sure, it's poured with and part of the foundation of the house, but that's the only part up high that's holding it back...the part that connects to the house foundation. Like I said, it's a single pour and part of the foundation.


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## Canarywood1 (May 5, 2012)

Well it's good that you have the drain system, and that it's working, they do have a tendency to plug up with soil, and yes the wall can be repaired probably better sooner than later, i'd get more than one estimate though,one way that I know of is to use helical piers, though there are more ways to do it, totally up to you.

I'll post a link to a helical pier repair, it's pretty much what you describe in your original post, good luck.

http://www.bobvila.com/articles/retaining-wall-repair/#.VP50yek5CXR


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## homeowner_101 (Apr 11, 2011)

Canarywood1 said:


> Well it's good that you have the drain system, and that it's working, they do have a tendency to plug up with soil, and yes the wall can be repaired probably better sooner than later, i'd get more than one estimate though,one way that I know of is to use helical piers, though there are more ways to do it, totally up to you.
> 
> I'll post a link to a helical pier repair, it's pretty much what you describe in your original post, good luck.
> 
> http://www.bobvila.com/articles/retaining-wall-repair/#.VP50yek5CXR


Thank you


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## homeowner_101 (Apr 11, 2011)

Canarywood1 said:


> Well it's good that you have the drain system, and that it's working, they do have a tendency to plug up with soil, and yes the wall can be repaired probably better sooner than later, i'd get more than one estimate though,one way that I know of is to use helical piers, though there are more ways to do it, totally up to you.
> 
> I'll post a link to a helical pier repair, it's pretty much what you describe in your original post, good luck.
> 
> http://www.bobvila.com/articles/retaining-wall-repair/#.VP50yek5CXR


I did some more searching after you gave the the term helical pier. I think that's exactly what I'd like to do. Similar to this in the video (at this starting point). But again, this is for outside on the retaining wall, not inside on my foundation....but same idea. Seems like a very good solution. 

http://youtu.be/4JX29hklrgE?t=1m21s


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## stadry (Jun 20, 2009)

helix/helical would also be my choice depending on avail budget however some excavation should also be included to place the wall in its original position ( in a perfect world ) :thumbsup:

ps - woody - full sun, wave height 1', 79f in islamorada


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## Daniel Holzman (Mar 10, 2009)

Leaning retaining walls are pretty common. There is an entire industry out there to fix those sorts of problems. You have found the helical pile solution, and there are other similar fixes involved other types of fixed anchors.

The solutions divide into two main categories. There are the options which require you to excavate the soil from behind the wall, install the fix, then replace the soil. Those alternatives includes deadmen (could be as simple as a large concrete block with an attached threaded rod) or reinforcing fabric attached to the wall, steel tiebacks, and similar options.T

Then there are the options that can be installed through the wall, without removing the soil. Those would included long threaded rods grouted in place, wedge type expansion anchors, and similar devices. The contractor drills a series of holes through the wall, installs the rods or anchors, then attaches a plate onto the face of the wall to hold the wall.

None of these options are low cost. The through the wall anchors require special equipment, not DIY. You may want to consider the option of getting some instruments installed on your wall. Some are very low cost, like a crackmeter (epoxies onto the wall, measures movement of the crack). There are also accurate bubble gages that measure how far out of vertical the wall is. You can install some of these gages yourself. You measure the movement of the wall over time, if it is stable or moving very slowly, you may choose not to do anything. Check out this web site for a selection of crack gages and other measuring devices http://www.humboldtmfg.com/concrete_crack_monitor_crack_gauge.html.


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## Canarywood1 (May 5, 2012)

stadry said:


> helix/helical would also be my choice depending on avail budget however some excavation should also be included to place the wall in its original position ( in a perfect world ) :thumbsup:
> 
> ps - woody - full sun, wave height 1', 79f in islamorada


 


Doesn't get much better than that, ENJOY.


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## concrete_joe (Oct 6, 2014)

a retaining wall like that perhaps should have been poured as triangle, fatter at bottom than top, and plumb on the exposed side.

the drain pipe, you can see it? is it just at the surface? there has to be drain down near foot of wall. 

does the soil slope away from this wall, is it flat, or slope into the wall?


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## homeowner_101 (Apr 11, 2011)

concrete_joe said:


> a retaining wall like that perhaps should have been poured as triangle, fatter at bottom than top, and plumb on the exposed side.
> 
> the drain pipe, you can see it? is it just at the surface? there has to be drain down near foot of wall.
> 
> does the soil slope away from this wall, is it flat, or slope into the wall?


I'll reply with more info and a photo when I get back home. I'm away from home for a few days.


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## stadry (Jun 20, 2009)

finding lots of wouldda's, shoulda's, & coulda's is also common :laughing:


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## jogr (Jul 24, 2007)

Does anyone have any personal experience with one of these fixes and how it held up long term? Say 15-20 years? To me they all look like expensive band-aids that don't look like they would hold up more than a few years. Would love to hear your long term experiences with these fixes.


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## stadry (Jun 20, 2009)

we just finished soil-nailing a wall according to eng specs w/75 25' rods @ 14degrees grouted in place,,, maybe it will work :whistling2: the eng had the hoa's ear & we duly noted our concerns,,, deadmen tell no tales so they work well however avail $$ is always an issue,,, helix would be the least expensive imo however excavation, in this instance, is strongly suggested :thumbsup:

btw, none of this work is diy imo :no: the drill alone's $80K then theres the mini-ex & 375cfm a/c, etc


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## homeowner_101 (Apr 11, 2011)

Here's what the wall looks like. It's the long one on the left I was asking about. It's not really bowed much at all. Just a tiny, tiny bit, but I was thinking if it was reasonable for the cost, anchoring it now would be a good idea so it can't move anymore and crack further. 

There is a perforated drain pipe buried with pea gravel along the poured footer, just like the foundation of the house.



















This is a closeup showing that it's poured as one piece with the foundation. It also has rebar rods inside just like the foundation.


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## Canarywood1 (May 5, 2012)

How thick are those walls and how old?


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## concretemasonry (Oct 10, 2006)

Your foundation walls are performing well because they usually have support it the top and are not cantilever walls. The walls you are concerned with are just cantilevered walls with no top support and probably the typical strip footing. They do not need as much reinforcement as a cantilever retaining wall.

The footings could be rotation and the wall could be under reinforced since a cantilever wall needs more reinforcement and a better footing. - The thickness of the wall is not a major factor if it is the same thickness (8" apparently) and thickening it is not feasible or effective.

Your best choice is to anchor the retaining walls back, using the soil as an anchor. Getting rid of the bowing id not really realistic unless you want to excavate the soil and build a new wall.

Dick


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## homeowner_101 (Apr 11, 2011)

Thanks everyone. The walls are same as the foundation, 8" thick and same type of concrete as foundation. Poured in 1996.


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## Canarywood1 (May 5, 2012)

homeowner_101 said:


> Thanks everyone. The walls are same as the foundation, 8" thick and same type of concrete as foundation. Poured in 1996
> 
> I'd see if there was a helical anchor contractor in your area and have him take a look, might have trouble getting equipment in there.


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## concrete_joe (Oct 6, 2014)

where does that gutter water go? i see it entering black irrigation pipe, but then where does it go?


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## homeowner_101 (Apr 11, 2011)

concrete_joe said:


> where does that gutter water go? i see it entering black irrigation pipe, but then where does it go?


That pipe is not perforated and it runs along that shorter wall for convenience and is buried in the yard until it's about 50 feet from the house so all the roof drain-off goes downhill to the ditch in the front yard. All my gutter drains are like that....buried and routed away from the house so it drains down the front hill.


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## stadry (Jun 20, 2009)

no one can put that wall back into vertical or take out the bow w/o full-depth excavation,,, because any anchors will probably be placed in 'fill', the holding capacity is suspect to me,,, how much $ do you want to throw at this problem ? 

i'd worry more about the crack & have that sealed to prevent wtr leaking/epoxy welding it back together


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## Daniel Holzman (Mar 10, 2009)

I do not see an obvious problem from the photos. All cantilever type retaining walls move a little when they are first loaded. If you want to end up with a perfectly plumb wall with no bow, you have to build the wall with a slight reverse camber and a slight off plumb tilt. The engineer carefully calculates the expected rotation of the wall, and a surveyor is needed to install the wall with such a tilt.

This is rarely done because most of the time the small rotation and bowing is not objectionable, and it is expensive and difficult to install a wall with reverse camber and tilt. In your case, you are assuming you have a problem because visually you believe you see the wall bowing. If the wall is stable but bowed, that is not evidence of a structural problem. If the wall continues to move well after construction, that could be a problem, and would best be evaluated by a licensed structural engineer.

If the wall develops cracks after construction that expand or change size, that could be a problem best evaluated by a professional. My suggestion is to do one of two things. Either hire a structural engineer to examine the wall and make repair suggestions. Or install some instrumentation (see my previous post) and monitor the wall over the next few years to see if it is stable. And you can always inject epoxy into a crack to seal it against moisture penetration if the crack is subject to freeze/thaw action.


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## giterrdone (Nov 30, 2015)

My cousin has run into this problem with his basement. Its kind of a niche topic that I don't completely understand, but I came across this post that has some good pointer. It breaks it down in laymen terms ahah! I guess we all can't be structural engineers!


http://www.foundationrepairservices.com/4-tips-prevent-retaining-wall-failure-2/


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## ront02769 (Nov 28, 2008)

Likely this issue has been dealt with nice the whole string ended like 9 months ago?


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