Failing Retaining Wall Inspection
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- čas přidán 26. 08. 2024
- Failing Retaining Wall Inspection - Shocking ! This is a commercial site that recently had a CMU style retaining wall installed and it's already showing signs of failure. The contractor didn't do any inspections so there's a lot of unknowns. We dug test holes to inspect the footer they installed and we were surprised with what we found.
Any chance you ran a metal detector across the footing and wall to see if they "forgot" some of the reinforcing steel?
If they cut corners to increase contractor profits, the contractor should tear it down and do it right at his own expense for not doing it honestly and correctly, and be charged for the fraud they are.
Yup, nothing better then adding to the dump, we have plenty of room on this rock
Okay, so I put my glasses on and reviewed the print again, and it is showing #4 rebar at 16 inch centers , but it looks like only 1 bar , and 1 #5 horizontal bar every 32 inches. I think some calculations were off. That"s not enough. And the proof of that is shown by WHERE the wall is breaking , which is in the top half of the wall, so the footer may or may not be correct, but it is not the only cause of the failure. Also the wall is not listing (leaning) which if it were , that would say that the footer is rolling over. The wall is breaking and moving horizontally which says there is not enough reinforcement in the wall. Maybe the math would show that every cell should have rebar and larger rebar as well.
As is true with nearly all catastrophic failures, it is rarely one huge mistake that is the problem, but rather a series of mistakes that add up to create the problem.
I'm still sure that there are more blueprint details that are not shown so nobody can judge just yet...
I agree. I'm not an engineer, but I have seen plenty of engineered plans for CMU and poured walls. I would expect to see #6 rebar every 16" vertically and a few layers of bond beams. 12" block fully grouted with 12" stone backfill to alleviate hydrostatic pressure. The cantilever for the footing should be at the rear, but the footing is not the problem here.
Rebar sizes seems adequate considering no apparent surcharge on retained soil. The 32" o.c. alternate spacing is still refering to vertical steel. What the specification is actually calling for is #4 rebar 16" o.c. in footing and above footing for the first 24" (three blocks high) then #5 32" o.c. (hence "alternate spacing") which needs to tie in to every other #4 16" o.c. and essentially be resting on top of footing (which would achieve the minimum 24" overlap requirement) and go all the way to top course of blocks. Based on how blocks are separating perpendicular to the plane/direction of wall It wouldn't surprise me if all cells weren't filled as it is likely required(didn't see that specification showed in vid) and or wrong horizontal reinforcement used. Another concerning fact is specification is for a 6' wall, as built it appears to be taller towards the back. With that many red flags I'd also question if drainage specification behind the wall was followed. I'd inspect cells for fill while I was at it. This wall may ultimately be nearly as expensive to fix than to demo and start over.
why would the footing be in front of the wall? surely the footing goes behind, to act as a cantilever, with the weight of the soil sitting on it keeping it held down? if you stick it out the front, then it can lift more easily and the bottom of the wall moves out
I mean, I don't have much knowledge on retaining walls but I can clearly see why it has to be this way... so the weight pushing up against the wall doesn't push the wall down like it is doing in this video
@@CbrF4i600cc i have a bit of experience, and a knowledge of the nz building code.
Dammmm.. What I do respect is you didn't shit on the other contractor even tho it looks likes he really screwed up....
A few comments already mentioned this. One type of failure mode for retaining walls is overturning. The lateral pressure from the soil can rotate the wall, counterclockwise in this case. Although not sure if that's the specific reason for the local bulging, there could be multiple issues. Seems a heel should have been included.
I don’t think the foundation had nothing to do with the bulging. I would first drill into wall to make sure grout inside core holes are filled through. Then check drainage. I would expect there be more weeks holes for drainage to relieve hydrostatic pressure against the wall.
This how we do it in milwaukee every 32 inches we install rebar when you done with the wall grout every rebar all the way to the top. Cause is a long wall you intall control joins every 10 feet that keeps it from cracking
The ground is sloped toward the street for drainage, so if you potholed at the far end of the wall (by the street) you would probably find the footer much closer to the surface. But since one of the immutable laws of the universe says that all footers must be level, then naturally at the upper end of the wall, it has to be deeper. Also the note on the print detail clearly shows the depth of the bottom of the footer is required to be a MINIMUM of 3 feet below grade.....there is no maximum depth shown. There is however, a maximum height of the wall shown at 6 feet above GRADE, (not from the top of the footer). That height of the wall was clearly exceeded at the upper end of the wall. I count 11 courses of block at 8 inches each, that used to mean 88 inches. I don't know what it is with this new math today, could be 2 feet, could be a porcupine!??!
Anyway , there should have either been a lot of dirt removal to reduce the load on the wall, or the wall should have been extra-extra robust to compensate for the increased load. Being very familiar with the real world of construction, I'm guessing that this was all discussed at some point, and a verbal decision/agreement was made to just go with it, which nobody will honor now that it's starting to hit the fan. Still, no blame can really be attached to the property owner, unless in fact they were the ones who declined to cover the added costs of doing it correctly. This is going to get messy in court I'd say. You did exactly what you were hired to do, and that is honorable. Sadly, you will probably get dragged into somebody else's battle, which is not a fun place to be.
I have said many many times...."You can pay to do it right, or you can pay more to do it over!!"
The fact that you think a professional, let alone an inexperienced (puting it mildly) contractor, would continue footing level into a slope for that length of wall makes me question if you've ever built these types of walls before. There's clear evidence the retaining wall is failing, which prompted the footing needing inspecting to begin with. It is not a huge leap to surmise that the contractor who built the wall didn't know what they were doing. Therefore the reasonable conclusion is that the footing is deficient based on the evidence found once they dug underground and not that perhaps the footing is actually deeper still. Nevermind that it is clearly not wide enough as measured.
The standard is and always has been, to install footings level. If you don't make the footer level it will compound problems the farther you go on the project. The block wall on top of this footer for example would not stack properly, throwing everything out of sinc. Typically if a footer needs to be stepped up, it will be done in a minimum of 2 foot increments. Not necessarily because of any requirement, but simply because concrete forms are typically 2 feet by 4 feet, and a single 2 foot step is simply easier and involves less labor than two - one foot steps. And it is mathematically the same volume.
There is now a sequel to this video , and it confirms most of my suspicions. In the process of repairing the wall they knocked a hole in the wall, exposing the flaws. The wall was not poured full and there was not enough rebar. You can only see a small portion of the wall, so you can only assume some things. But since the hole they made was at the bottom of the wall, and they were later able to fill it from the top, is proof that there were no horizontal bond beams. At least in that area.They removed the cap blocks in that spot and poured the wall full, but they should have done the entire length of the wall. They poured some massive deadman footers and columns to reinforce the wall, but in between the columns the wall will continue to move because it has already been compromised and isn't poured full of concrete. It may last for a while, probably until a severe weather system dumps heavy rain for several days and then it will collapse.
Everyone can see that none of this project was done to the letter of the engineers specs, however you can also see that the footer was not the cause of the failure. The evidence is in the asphalt on the lower level. Zero cracking or heaving or separation can be seen. The footer was never in motion. Yes it was not done correctly. No argument there. Although I am willing to bet that it is actually 3 feet wide, and the correct thickness. There is about 12 inches showing, the block is 12 inches and I bet there is 12 inches on the other side that you can't see. When they poured the footer I bet the grunts in the trench stabbed their verts in the center of the footer just out of habit, and didnt notice it until they came back to lay the block. Which honestly might not have even been the same contractor. How many masons do you know that pour concrete? They are out there, but not very many.
Very expensive failure, and very expensive repair. And now the property owner has some massive columns to dodge every time they drive to the back of the building. And a wall that will eventually collapse anyway.
The ole squinty eyes and t shirt mask
😅
I have that dust mask you guys were using patent pending
Look the engineers drawing is also incorrect. The best retaining walls are cantilever under the area being retained. The problem is it an extremely expensive alternative. And require huge amounts of stone. And rebar.
the wall is the main problem even if the footing was not followed to specs.
The lack of adequate weep holes seems to be the reason for the bulging of walls.
Good point
Great video and yes we all love tacos especially on Tuesdays
But why did not the engineer himself go on site to see what the contractor was doing????????????
2'20" - check the shadows ... cement saws always run best at 7 am ... full throttle ... pro tip there ...
Love it!
No expansion joints either. should be built in every 6metres
Maybe the block layers centered the wall on the foundation rather than placing it toward one side.
The footing should go behind the wall not in front for stability
the main problem i see here is that they didnt hire you guys in the first place 😉
The footing should be on the inside of the retaining wall, not the outside. Engineer is to blame as well for this
I'm sure you meant nothing by the tacos comment but in today's sue happy world you really have to be careful how you say things...as for the wall, I see some problems on both sides of the equation...(engineering AND construction). I hope there are more details on the wall blueprint. I'm guessing there are , but if not then it is woefully inadequate. Some quick calculations would show the massive amount of weight pushing on that wall. There should have been vertical and horizontal bond beams a minimum of every 24 inches with at least 2 number 4 rebar each, and at least a 24 x 24 inch column integrated into the wall about every 10 linear feet. Yes the footer and wall are not as shown on the detail and that is going to bite somebody in the butt. However we all know that the deeper the footer is the more stable it is going to be. I would almost bet that they centered the wall over the footer rather than on the edge but in the overall big picture it's the wall that is moving and buckling , not the footer.
The property owner has no responsibility to know anything about the methods or materials used. Their only responsibility is to do the due diligence of hiring reputable contractors and engineers. Outside of that, 100 % of the legal liability is owned by the engineers and contractors.
Understand that I'm not defending either one of them....there isn't enough information in this short video for anyone to make an accurate judgement. Too many variables that you can't see in this video, ie: what is the soil type on the other side of the wall?, did the print call for a drain at the bottom of the wall? ( I see drain pipes sticking out but how far do they go) did the print call for drain rock on the inside?, if so, how much? what about mesh mats in the drain rock? Just too many unknowns at this point....
The real problem here is their is not enough 3/4 gravel out behind the wall
block like that is also just a shitty retaining wall material
No backing thats the problem. Have a look how the ozzies do limestone walls
Not sure why all the shitty comments, but I thought it was a great video.
Yes sir kid is right!
Ooooooooo no •••°•••°~~~~~
Now what are you going to do ??
this kind a coruption are similiar from other country..
we are not diffrent after all..
Tacos? Hummm
It is better not to hire an engineer and force a contractor to build according to the plan.
Contractors should build the retaining wall according to their knowledge, not according to the method of the "experts". When the contractor needs professional advice, he will buy it as needed.
the customer should have been familiar with his plans and should have been watching the build.
I agree, the customer was in a jam because there was a major storm and the old wall collapsed. Thanks for watching
Doesn't the engineer also have fault...,not only the contractor?????
@@mandodebbiechavarria6201 as I watched the video, it looked like the engineer designed it correctly. After that, the engineer is out of it.
Customer has no responsibility to oversee contractors, no reasons to know how the job should be done and how to read engineer's plans. Customer is supposed to pay, and contractor is supposed to to the job according to specifications. Blaming customer for contractor's poor execution is just mindboggling.
@@yohatch my question is how much was the job quoted at initially. If there were at least one or two other quotes and the customer decided to go with cheapest, particularly if significantly cheaper than other quotes then that's a very expensive lesson. If customer went with licensed contractor and middle or even high bid then that's entirely on contractor.
@5:03 really ???….racism is learned folks, feel bad for the kiddo
It's truly a shame that we live in a time where a kid mentioning Tacos is some how racist. My son listened to the song "It's raining tacos" over and over. So he thought saying eating Tacos would be a funny thing to add to the video. But there's always someone that gets offended and the race card is the first thing to come out. I showed him your comment so he can learn the real lesson here. Which is some people will find issues regardless of the context or true meaning. None the less the previous wall was built by white guys (which I knew prior to posting this video) and my wife is 25% Hispanic.
Do no
Don't know. Surcharge failure. Test block. Footing is holding. Grouted? Every cell?
Drainage. First row take out spec mix between header
Maybe double wall and extend footer. Footer Not the problem
Go get some Tacos? You don’t know who the fuck built that wall but buddy, I hope your high and mighty ends up digging the whole thing out by hand.
I'm not sure what to make of your comment but it seems angry?? The tacos was a joke. My 6 year old son said "tacos are the best" which I think is a line from a kids show. My apologies if this triggered you.
@@srmcontracting No apologies needed. This is the world that we are now living in. Too many people are so sensitive and ready to pounce over nothing. Tacos are good!
@@srmcontracting Mexican = Tacos, triggered him. I image most Mexicans would proudly give the ok to that equation. BTW Did the owner end up in court with the contractor?
@@lightning9279 I guess that was it! He sure did, I had to testify as an "expert witness". They found him guilty and he has to pay back the cost for a replacement wall.
@@srmcontracting Sweet!
what kind of inspector are you? Core drill and Xray, this is ridiculous and unnecessary
Im not an inspector, Im a contractor that buildings retaining walls among many other things. I was hired by the property owner to dig these holes so the engineer and local inspector could do an inspection. Thanks for watching