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This seems like game changing technology. There are a heap of such walls around here, some built long ago by Dalmation immigrants (and some allegedly by German
by beachy 3y ago
This seems like game changing technology. There are a heap of such walls around here, some built long ago by Dalmation immigrants (and some allegedly by German POWs). It's quite labour intensive and highly skilled to create them.
We have some on our property, used to retain the hillside after land slips. They were built with an excavator by a gnarly old guy who was unbelievably skilled.
One thing I wonder is whether these are safe. These things terrify the shit out of me, as one toppling rock of that size could instantly kill a child.
Walls built by human operators of sufficient skill are safe (I know, I went around and tried to wobble every single rock to make sure). But are these built to the same level?
- toomuchtodo 3y agoYou could potentially shotcrete (spray it with concrete to reinforce) the wall after the robotic excavator is done if you’re concerned about stability. I can’t speak to whether you can highly automate this as well, but it seems possible with current state robotics with human operators. https://en.wikipedia.org/wiki/Shotcrete https://en.wikipedia.org/wiki/Shotcrete https://www.geostabilization.com/technology/shotcrete-robot/ https://www.geostabilization.com/technology/shotcrete-robot/ https://dawinvehicles.en.made-in-china.com/product/jBMnaOKdLgrL/China-Robotic-Shotcrete-Arm-Concrete-Spraying-Machine-30m3-Per-Hour-Output.html https://dawinvehicles.en.made-in-china.com/product/jBMnaOKdL...
- myegorov 3y agoThe ability of a dry stack retaining wall to shift and breathe is a feature, not a bug. For stone walls that require added reinforcement against lateral loads, look into tiebacks or geogrid reinforcement.
- toomuchtodo 3y agoAppreciate this. Where can we read more on this engineering? All citations are welcome, I am fascinated by this engineering domain.
- gerdesj 3y agoThere are Civil Engineers here (I only studied it at Uni - I ended up in IT!) When you deploy a structure like a retaining wall you want to try and ensure that the materials you use will retain their properties as long as possible and if part of it fails, it should not case the whole structure to fail. Add additional design requirements as you like eg colour and texture but always think about function first or you will regret it later! In a garden setting, you will want to consider: gabions, drystone walling and "sleepers" (large lumps of wood - like railway sleepers). Some quick material thoughts: Wood is prone to rotting, so ensure it is treated and well drained. Drystone walling can be prone to collapse unless it is allowed to drain properly and plants/weeds should be removed. It should be slanted at around 5 degrees from vertical to resist collapse. Gabions made of galvanized steel wire are extremely strong and resistant to pretty much anything. Devon Popples are an ideal filling for gabions and make a phenomenal structure. I built a deck part way down in my garden. It is about 5m wide and sticks out about 1.8m. Behind it is a sleeper retaining wall which is about 1.8m high. I angled it back by about 2 degrees from vertical. I laid it on a concrete strip to spread the load and gravel base and back filled with quite a lot of scrap brick and rubbish for drainage. I used some 2m x 10mm stainless steel threaded rods embedded into the conc base to ensure horizontal stability (horizontal shear). I used 180mm, No. 10 passivated screws to keep the wall together whilst I built it and back filled. "Where can we read more on this engineering" It's everywhere but you will have to deal with local conditions. I am not convinced you are what you claim.
- gausshaus 3y agoI'm not finding info on "Devon Popples" for use in gabions. Was that a typo? If so, curious what the ideal filling is.
- saalweachter 3y agoAnother quick tip: resist the urge to stack your stones long-ways parallel to the course of wall. Instead, put the longest dimension perpendicular to the wall. This makes it much harder for the wall to fall outward as it shifts.
- Probiotic6081 3y agoOr make the walls squiggly ~~~ for extra structural integrity
- abduhl 3y agoShotcrete is regularly applied via robot in mining. The problem with shotcrete in open cell designs such as this is overspray and plugging of the large voids. Gabion baskets are likely a better idea if you have stability problems and want to do a similar kind of automation.
- seabrookmx 3y agoThis defeats the purpose a little bit though because the environmental benefit is to _not_ use concrete, as producing it has very high CO2 output. They use shotcrete a lot here in BC where cliffs are close to the road, but usually when it's soil or more loose material. Any rock structures (natural or man made) are typically left bare.
- dventimi 3y agoPerhaps concrete in construction and demolition waste could be used. https://www.bigrentz.com/blog/construction-waste-statistics https://www.bigrentz.com/blog/construction-waste-statistics
- gerdesj 3y ago"You could potentially shotcrete" You could stop water draining through the retaining wall and turn it into a dam, which will not end well. My back garden/yard has a 40m drop to a lawn. The levels are managed by dry stone walls. Soil here is heavy clay with really heavy clay sub soil, so efficient drainage is imperative. As well as drystone walls, consider gabions which can form phenomenally tough retaining walls. You can plant on them too rather than having to weed drystone walls. Gabions are much more resistant to plants forcing joints apart than drystone walls.
- toomuchtodo 3y agoYou would still need humans to erect the gabions though, no? Trying to understand the best optimization use case for this product and best fit final results. Please excuse my knowledge gaps! I’m am trying to fill those gaps.
- gerdesj 3y agoWhat problem are you trying to fix?
- toomuchtodo 3y agoReduction in human labor for building these types of structures. The world is getting old fast, but infrastructure is still required, both new and maintenance of what exists today. Also, job assistance that reduces the toll on humans in this industry. This prevents treating the human as a consumable when the automation can be human driven, increasing quality of life and potential career longevity (if desired). Not replacing humans, to be clear, but helping them build better with less effort. Thank you for indulging me. I hope to eventually leave tech to build things that are needed that are built to last (I too am getting old fast).
- jacquesm 3y agoYou can fill gabions that have been pre-made by using a mini excavator. Or you can do it by hand but that's pretty labor intensive, unless you like wheelbarrows and buckets I would advise against it. Personal experience and all that ;) The important thing with gabion is to realize that they still need careful planning, anchoring, leveling and possibly a foundation to ensure that they aren't going to shift over time.
- coryrc 3y agoIf the wall is going to move a little shotcrete ain't going to stop it.
- abduhl 3y agoI’d disagree with this. The general rule in mining is “six inches of shotcrete will hold up the world.”
- coryrc 3y agoUnder compression. If you tried to stop a dry-stack wall from moving, it'd be under tension.
- defrost 3y agoNot to mention the shotcrete | granite rock binding will shred itself after a year or two of daily heat|cool cycling in the sun - the expansion rates of the two materials don't match.
- landemva 3y agoThe shotcrete I have been around was sprayed onto hogwire (already on the rock) and then bolted. It was not just coated onto existing rock as if it was a cake icing.
- hutzlibu 3y agoOne of the ideas of this project is, to NOT use concrete, to not have CO2 emmisions. And depending on the "skill" of the robot and its algorithms, it could be very stable. I know that quite some ancient buildings in south america are put together just with stones put together(with precision and shaping of stones). They survived earthquakes and are still standing. So if enough stones of various shapes are avaiable - you won't need concrete. The weight and friction will hold them together.
- mauvehaus 3y agoVisiting Scotland, I was told that the apparent lack of stability is what keeps the sheep from pushing against the dry stone walls there. Apocryphal or true? No idea. It's intriguing to think that sheep have a sense for stable construction, and that people have learned to deceive it.
- daxfohl 3y agoThey had no problem escaping through them in Clarkson's Farm.
- kbenson 3y agoI really enjoyed that show, but I have no confidence that production assistants weren't gallavanting about at night acting as gremlins. Clarkson is first and foremost an entertainer, and I'm sure he'd agree with that assessment.
- chaboud 3y agoClarkson is the sort of guy who would have both friend and foe knocking over his walls just to mess with him. Nonetheless, sheep farming can be incredibly difficult, and sheep love to assert just enough independence to be annoying.
- 123pie123 3y agothe adjoining farm next to our backgarden had sheep that was obsessed with getting into my backgarden - no idea why. they would jump over the 5ft wall with barb on the top. When we complained he move the sheep to another field, they escaped that field and entered our back garden through a totaly different way - through our front garden. eating loads of our plants - I can understand the pain Clarkson went through (made up or not)
- lapsed_pacifist 3y agoNot true. A well built fieldstone wall is massive, we estimate around .5T per linear yard when we build one to 4ft. with cope stones. Sheep will not knock it over, but cattle can. For that reason, through-stones are allowed to protrude a few inches on normal pasture wall for sheep, but you should make them flush on walls for cattle because the cows will try to use the protrusions to scratch themselves and could knock the wall over. A well built wall doesn't appear unstable. One of the tests is whether or not you can see any daylight through the wall, and the wall should easily support the weight of several people leaning against it.