Construct retaining wall / slope stabilization cost-effectively

In the retaining wall discussions, I always feel as if these are meetings of people who have never seen a slope slide after heavy rain and have only covered a bit of optics and electricity in physics class.

One side is (supposedly) solid mass (plus potential energy) and the other side only air: of course, that presses – even if the internal strength of the mass "resists" (only then not dramatically). If it gets too wet (or experiences similar effects), then being rock solid but about to tip over is comparatively the bravest thing the wall can do.

Theodor in the soccer goal still holds, the hairstyle with Three-Weather-Hold hairspray too, but unfortunately, the wall only holds in father’s previous experience.

Three things help here, ideally in this triad combination: anchoring (L-shaped stones do nothing else), inclination against the direction of pressure, and "reinforcement" (of the pressing mass itself!) with root systems or the like.

Reinforcement in the wall does not make it strong, only stiff. That is also good and useful as a fourth measure but does not replace the first three. The stiffness of the wall only makes the difference between crumbling and tipping over. Because crumbling requires less force, and to make the forces visible, laypeople mistakenly consider the stiffness to be sufficient except for century events.

Forces often only become evident when one side becomes more than equivalent – denying their existence until then can nevertheless be a grievous sin.

I dare to claim to quite reliably tell whether retaining wall builders are physics teachers or business economists or computer scientists

Yes, provided you have a mountain of earth behind you. That should not be generalized. We were, so to speak, the 2-meter mountain that was piled up for the house; behind us is the last house at the same level. After 5 years I can say the house stands, the wall stands, and we’ve felt like we had 5 storms per year. The OP is only bringing their property up to the same house level. There is nothing with statics there.

make a foundation (dig 1m deep, 20 cm gravel layer and 80 cm concrete with rebar) and place concrete formwork blocks on it, equip with reinforcing steel and pour concrete. You should use 26 or 29 cm blocks, but he probably won’t provide a static calculation or say anything about it.

Hello Webmaster-uk

Last year I processed just over 1,000 concrete formwork blocks for an underground climate cellar. All done by myself. Mixed and applied concrete with 3 men. You have to know what you’re getting into. Then it works.
First of all, you should use 30 cm formwork blocks. The earth pressure is not to be underestimated. The blocks, the concrete gravel and the cement can be easily transported from the street with a wheelbarrow. It is hard work and not done over a weekend.
I consider digging 1 meter deep for the foundation a bit exaggerated, but it certainly doesn’t hurt.
So: first dig out the foundation. Because of the earth pressure, I would also set the foundation into the property. Ideally every 5 meters, 2 meters deep. To explain it better: foundation along the entire length where the wall will be built and from there at a 90° angle 2 meters into the property lay foundation. No wall will be set on that, but it stabilizes.
Then RCL into the foundation and compact it well. Then pour concrete. Insert 12 mm reinforcing steel rods into the concrete. One every 50 cm. At least 20 cm deep and then looking one meter upwards.
You have to make sure the reinforcing steel lies in the gaps of the formwork blocks.
Afterwards, build the formwork blocks in a staggered pattern. Arm each layer with at least 2 rods of 8 mm steel. So, horizontally 2 rods per layer and continue the 12 mm vertical rods. Pour concrete and at some point the wall stands.
When installing the blocks, you have to work with wedges. The formwork blocks all differ by a few millimeters in height.
Finally: use formwork blocks 30 x 25 x 50. You have to search a bit. Most only offer 20 cm high blocks.

Steven

Maybe the tip has already been given, but better once too often than ... It is best to pour concrete already after setting 2-3 rows of formwork blocks. Otherwise, the formwork blocks may break in the lower rows due to their own weight.

It’s best to pour concrete already after setting 2-3 rows of formwork blocks. Otherwise, the blocks in the lower rows may break due to their own weight.

Hello

completely correct. But they are more likely to be pushed out when filling. I don’t think they break. That is also the reason why ready-mix concrete is not ideal. If the driver lets it run, the chance that the blocks are pushed out of alignment is high.

Steven

Steven

Maybe the tip has already been given,

Then I must have overlooked it, otherwise I would have added my two cents: the phenomenon you fear would be unproblematic since the formwork blocks are only lost formwork, and even a localized water ingress through cracks does not dangerously weaken the "wall."

What can be more dangerous to their stability is the layer-by-layer setting of the poured concrete analogous to the setting of the formwork block rows. The overly clever DIYer fills the concrete, say, up to the top edge of the web of the third row, then takes a lunch break, and afterwards sets the next five rows.

The upper part then "hangs" like on a proverbial silk thread on one groove and the reinforcing steel bars set across layers. Flip back one page, there I have already warned against the naive physics of the milkmaid.

Due to vacation-related absence, I am getting back here in my created thread with a delay.
First of all, many thanks for all your answers and tips, which unfortunately only make me even more uncertain about how to proceed best/ideally now.

I don’t know if maybe the issue with the statics and the slope/filling is being rated too strongly because of my first statement, so I quickly created a sketch with Paint to show what is supposed to be supported.

The thick beam is supposed to be the wall at 2 meters height, which is currently still there. Instead of the wall, there is currently a chain-link fence stretched there. The black line represents the current property. The green line shows how the height level is to be adjusted, namely to the uppermost black line, because from there the property continues relatively straight for another 30 meters.
Between the lowest spot and the medium-low spot, there are 25 fir trees in three rows across the width of the property that still need to be felled.

I want to use as much of the property as possible, but it should also be in relation to the effort. I don’t have to/want to "waste" my money at this point at all costs but still use as much of the property as possible.

Therefore also my question whether I should make the wall 2 meters high to be able to fill completely straight up to the property boundary or maybe not make the wall that high and then have a slope that I can stabilize and cover with shrubs as a privacy screen to the property below.

But due to the location of the property, it is not possible to do the whole thing with ready-mix concrete. The material would also have to be transported 40 meters from in front of the house to behind the house.

Physically I am fit and 2 years ago I completely renovated a house myself. So there is craft experience and the will