Who knows about stacked-block retaining walls?

[Sodo]

The helical anchors will arrive today Sunday.
Crazy what Amazon has done to projects, with one-day delivery.
I cannot IMAGINE they will hold as well as 6ft (or even 8ft) T-Posts.
Maybe I'll just toss them in the toybox and go get 12 T-posts.

I'll know how easily (or difficult) a 5 foot post drives in, fairly soon.
Driving 12 T-posts could be a chore, but I have 2 days....

Here's a pic of a sharpened T-post and my two drive methods.
I bought the gas-powered driver for another project.
Intended to sell it after that project, but didn't.
All you tool-guys understand how that goes.

 

[LouNY]

Good luck with your retaining wall, I see a lot of them around here. Many go from sloped back to getting ready to fall down in a few years. I expect much of that is from frost heaves.

 

[Streetcar]

Place your geotextile on vertical face of soil and have it turn horizontally to extend in between the blocks. Weak point of tie backs will be attachment to blocks

 

[Flogger]

We installed appx 180 feet of wall that ranged from 2 to 8 blocks high backfilled with crushed stone. The base was level contoured with at least 1 block below ground level. We installed 2 drains in the lowest spot and topped with 8” of topsoil graded and lapped over the top of the blocks. No tiebacks of any kind. Looked absolutely fantastic. We would listen to the boaters ooh an aah all summer long. Right or wrong 20 years later when we sold the place the wall hadn’t moved a bit.

Also we stacked them 8 to 10 blocks high on the back side of the garage and made a parking pad that sloped to the open end. We had 3 boat trailers stacked and parked on the pad. It had no drains and no tiebacks and stood solid for the same 20 years.
With a solid base these blocks are amazing.

 

[Sodo]

Thx Flogger that's good to hear.
Three significant details that influence success / failure !
------> (conditions, conditions, & conditions).
It's "the unknown", "changes", and "the future" (seismic?) that should be the impetus for overkill, not internet glory.

From my (very simple and limited, engineer but NOT geotech,....) understanding,
the geotextile layup is a 6-foot thick retaining wall,
and the block wall leaning against it is mostly a decorative facing.
But this block wall supports the topsoil bank above it--- that will hide the geotex layup and I want it to remain visibly straight.
The topsoil bank sitting up higher than the block (the row count ! )..... wants to settle in behind the wall and push it out.
per Curly Dave's explanation. But there's only a little drained fill that wants to get to its angle of repose.
It's not mud trying to go 'level'.

----- streetcar mentioned a way to use the weight above to secure some "added geotextile".

How much that big (16 foot) sand layup is gonna settle though, -----> is an unknown for me to discover in time

I'll tie this wall back to 'stack the deck' because it is 4 blocks higher than the mfr recommendation.
And because this retired guy has two days to fiddle while the wall-builders are away on another job.

===========================

The helical anchors available quickly on Amazon.....were un-impressive (no suprise).
I'll put them in my toybox for some other project.

Driving 6 foot fenceposts in with a gas-powered fencepost driver.

Well they didn't just fly in.
But I think tight enough,
and splayed apart they will resist pullout.
I think this arrangement is much stronger than plastic geotex deadmans could ever be.
If I'm bored tomorrow I'll screw some of those little helical anchors in too, I'm curious.

I'll weld this #5 Rebar frame all together.
That one up at the right was my "test-pole" to see how hard they drove in.
I'll attach to it simply because "I can".

Here's 3 drilled blocks for row 6
and 3 drilled blocks for row 10.
Rebars poked thru a hole with a welded dogleg to retain it in the block.
I'll weld tie-bars from the blocks to the frame as the wall goes up.

 

[airbiscuit]

Mice job. Get back to us in about 40 years, and tell us how it looks!

 

[Sodo]

I welded the eight 6ft T-Posts and rebar rectangle together.
It's really solid.
No way in h*ll is a plastic deadman as strong as this method.

From the other buried steel I find here, I'm sure this will last 40 years and more.
I doubt this little house will still be here in 40 years though.

I lengthened a couple 2.8" helical anchors with rebar and screwed them in.
Mostly was just curious “how they go in”.
They got tangled in geotextile, but eventually got them in, and welded.
Every little bit helps (helps the overkill !)

 

[goeduck]

Same state, and maybe county, as you. No tree protection laws would stop you from taking out a few trees. I do it on a regular basis. If any of those trees are western red cedar, they do not like their surface roots covered, they typically die. I can't tell on my phone what type of trees those are.

 

[Sodo]

They're Redwoods, planted in 1985.
I would like them better if not so close to the house.
The 40" is 11 feet from the house.
Someday they have to be taken out.
It's a 1 bdrm, decent condition, but low-value house (rental).

Here's row 6, welded to the tieback structure

Here's row 9 welded to the tieback structure.
This wall ain't gonna tip over.

Just about done, and ready to backfill the dirt bank.
I'll put some of that black woven fabric over the gravel before covering it with soil.

Pavers tomorrow.

 

[RayIN]

I do know one thing about constructing a block retaining wall.
Never construct in winter months. I hired a landscape company to construct 2 retaining walls. Both have sank about 1" in one area, with that 1" void clearly visible.
Called them back to inspect the void. A new man showed up and immediately asked if there was drainage tile behind the walls. No there is not I replied. He said there's the cause, no way to install it now but remove everything and start over, and the owner said he will not do that since it's been 4 years.
Now I've complained every year, but nothing in writing, my bad.