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Autonomous excavator constructs a six-metre-high dry-stone wall

ethz.ch

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Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#161

Post by Matumio »

Daub wrote: post #55

Having made a few dry stone walls I can attest to the merit of this achievement. Judging where rocks are to be placed, and in what orientation is a zen art. Anecdotally... I once tried to get wild flowers to grow on a stone wall. Every year we would seed the wall, only for the seeds to fall out or be eaten by birds. On inspiration, my boss filled a few shotgun cartridges up with seeds and fired them at the wall. Perf…

This is the way you use a gun. What a flowery blossoming place this world would be. Reminds me of https://en.wikipedia.org/wiki/Swords_to_ploughshares

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#162

Post by berkes »

SiempreViernes wrote: post #141
diroussel wrote: post #138

Earlier quoted context omitted.

So are you saying we couldn’t estimate the structural properties of autonomous built dry walls from local stone? Or that the error bars would be unacceptably large? Or just that this approach would only work with certain stone in certain locations?

I think the problem is more that you cannot at all guarantee a specific performance of the structure ahead of time, because you can't know what the properties of the local rocks will be before you are on site and have measured them all.

Doesn't that apply to wood too? Yet we use wood to build houses almost everywhere.

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#163

Post by _a_a_a_ »

HPsquared wrote: post #143
fullspectrumdev wrote: post #134

Earlier quoted context omitted.

Very common in rural Ireland, and having such a wall repaired or made is either going to cost you nothing or a LOT of money.

As with many of the best things in life, they are either free or very expensive.

Sex? :)

(edit: no, that was not an offer, sorry)

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#165

Post by worik »

samtho wrote: post #86
schiffern wrote: post #74

Earlier quoted context omitted.

Not only is this a technical marvel, but it has potential construction physics implications. In simple terms, currently we expend energy to fragment rock, and then we expend additional energy (as concrete) to glue it back together. We do all this to re-arrange rocks into a shape (and strength) we want, and most importantly to do it cheap . Suddenly, an alternative just got a lot cheaper. Clearly this isn't fully bake…

The problem with dry stone construction is that you cannot determine the performance characteristics required for, say, a building foundation. Not all boulders are created equal, but a professional concrete pour, mixed and installed to the manufacturer’s specification is going to have a guaranteed maximum strength- something random boulders will not have. What we can do is create our own concrete mix using Portland c…

With concrete you have outsourced, not solved, that problem

There's a lot of drystone walls here, in Aotearoa, but not of buildings.

There is a related technique for buildings, building from rubble, using lime morter.

I live in a building partly built that way

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#166

Post by jlevers »

jvidalv wrote: post #110

Just wanted to share that in my country (Spain) and more concretely in my area (rural part of Catalonia) we have a building technique called “Pedra Seca” literal translation is “Dry Stone”. It basically involves building stuff with just rocks, nothing more. It’s still in use mostly in agricultural fields. Here are a few examples: https://dd9de8c7b7.cbaul-cdnwnd.com/b5fbcf0e77b7b72ef95acd62... https://static1.ara.cat/…

I rode through a huge area filled with these sorts of walls somewhere wayyy down a dirt road in rural central Mexico, sorta near Zacatecas. It looked like it was once a vineyard, or something like that...I'd never seen walls that looked this way before. Really beautiful. I had no idea that it was originally a European thing.

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#167

Post by m463 »

Daub wrote: post #55

Having made a few dry stone walls I can attest to the merit of this achievement. Judging where rocks are to be placed, and in what orientation is a zen art. Anecdotally... I once tried to get wild flowers to grow on a stone wall. Every year we would seed the wall, only for the seeds to fall out or be eaten by birds. On inspiration, my boss filled a few shotgun cartridges up with seeds and fired them at the wall. Perf…

> my boss filled a few shotgun cartridges up with seeds and fired them at the wall.

A friend of mind had a hill in his yard, and hired a guy that knew the local seed mix to hydroseed it. It went well.

https://en.wikipedia.org/wiki/Hydroseeding

Can't figure a good word would be for what your boss did. It's not quite pyroseeding...

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#168

Post by _tom_ »

SiempreViernes wrote: post #141
diroussel wrote: post #138

Earlier quoted context omitted.

So are you saying we couldn’t estimate the structural properties of autonomous built dry walls from local stone? Or that the error bars would be unacceptably large? Or just that this approach would only work with certain stone in certain locations?

I think the problem is more that you cannot at all guarantee a specific performance of the structure ahead of time, because you can't know what the properties of the local rocks will be before you are on site and have measured them all.

The interesting thing here is you can feasibly measure them all.

Not ahead of time, but as you build.

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#170

Post by legulere »

samtho wrote: post #86
schiffern wrote: post #74

Earlier quoted context omitted.

Not only is this a technical marvel, but it has potential construction physics implications. In simple terms, currently we expend energy to fragment rock, and then we expend additional energy (as concrete) to glue it back together. We do all this to re-arrange rocks into a shape (and strength) we want, and most importantly to do it cheap . Suddenly, an alternative just got a lot cheaper. Clearly this isn't fully bake…

The problem with dry stone construction is that you cannot determine the performance characteristics required for, say, a building foundation. Not all boulders are created equal, but a professional concrete pour, mixed and installed to the manufacturer’s specification is going to have a guaranteed maximum strength- something random boulders will not have. What we can do is create our own concrete mix using Portland c…

It’s more difficult but still possible. Mountain passes in Switzerland are often built on dry walls
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