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Hack
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Is that a mortarless retaining wall (ie: Alan Block)?
That's a massive fix...if they decide to fix it.
One would have to remove all of the fill material and block courses down to where it is stable, and then rebuild.
But that's a simplistic way of looking at it. A catastrophic failure like that will have to be rebuilt from the ground up.
I'd like to see more on this....have any more pics or news reports?

EDIT: Looking at the pic...hard to tell, but I don't see any geo-grid installed. It's probably in there, as I can't imagine any wall that size going up without an engineered design.
 

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Discussion Starter · #5 ·
asevereid said:
Is that a mortarless retaining wall (ie: Alan Block)? That's a massive fix...if they decide to fix it. One would have to remove all of the fill material and block courses down to where it is stable, and then rebuild. But that's a simplistic way of looking at it. A catastrophic failure like that will have to be rebuilt from the ground up. I'd like to see more on this....have any more pics or news reports?
Yep it's them kind of blocks. A good friend is the general for the company who built it. I'm sure I will get more info.
 

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Repair & Renovation
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It's crazy how tall they build those walls
 

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Box Builder
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Obvously there doesn't seem to be proper drainage. But, what is the face of that wall made out of? Fixing it has to be a real nightmare.
 

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Hack
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Its hard to tell, how big do you think each block is?
If they are Allan Block products they would be a standard 8"x12"x18" with a certain amount of setback.
For a wall that size I think a 12 degree (or more if it's available) setback on the block would be used.
Drainage may have been an issue as it tends to get more important and integral to the walls construction as it grows in height.
These walls can hold back an immense amount of pressure, but as with anything the building process becomes crucial as the scope increases.

The largest build I was ever involved in was a 16'-18' tall wall that required a pad on top for RV parking and a set of stairs built in to it.
We had an engineer come by to check on the work after every 5 courses of block. PITA.
 

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Drywall Slave
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Low end/ High production subdivisions ! Looks about right to me!:whistling
 

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On a very minor scale, maybe 25 feet high, I just saw a residential sub-division in Mesquite NV built with this or somesthing similar.

I asked the site manager about "tie-backs", which he did not undersatnd, and he said something about "wire mesh" every 3 courses.... or something like that.

Does anyone know what he might be talking about.?

Does that Allan assembly have any type tyback, or any type "fill consolidation" system.

Would a drainage system just be something like a lattice of french type drains.??

TIA

Best

Peter
 

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It looks like the tiebacks went with the wall when it failed, they lost 8-10 feet inside the wall.

I have seen a plastic tie back material that was only 7 or 8 feet wide used every few courses but that would not have helped here.

They is a wall twice as high as that in Northern NJ that I could see the same thing happening. Condos are built 25' from the wall.
 

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Hack
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What they use for tieback into the soil is a geotextile grid...looks like heavy duty snowfence. The grid size mat size, and placement is spec'd by the engineer. It is placed in between courses of block and the backfill material is compacted over it...'tying' the lifts of backfill together.
There is typically clean crush placed directly behind the block as well as drain cloth (landscape fabric, or similar material) that ultimately feeds to a perforated drain pipe.

Other than that I've understood that common tieback procedures can be used with the Allan Block system, but they tend to offer their geogrid system as a part of the package, or the engineer specs it.

 

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Repair & Renovation
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It looks like the tiebacks went with the wall when it failed, they lost 8-10 feet inside the wall.

I have seen a plastic tie back material that was only 7 or 8 feet wide used every few courses but that would not have helped here.

They is a wall twice as high as that in Northern NJ that I could see the same thing happening. Condos are built 25' from the wall.
I know what your talking about.. is it on 46 by the great notch bar ? That wall has to be 100'+ easy
 
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