Farmers in New England would have loved this. Miles and miles of stone walls just hidden in forests/woods.
Autonomous excavator constructs a six-metre-high dry-stone wall
121–130 of 190 posts
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#122Just 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/…
Dry stone walling is also very common in the UK. It's a complex and now expensive skill, but a properly-built (this bit is key) wall will stay put for well over a hundred years because the rocks can shift a little rather then cracking the structure as temperatures change and water drains right out of them.
It's also very locally distinctive because the shape of the stones and therefore the wall layout and texture depends on the stones you naturally have nearby.
https://en.wikipedia.org/wiki/Dry_stone#/media/File%3ADry_st...
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#123Having 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…
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…
Tensile strength will be a problem. Compression will be solved eventually, the tetris part also. But if there are to be tensile or twisting loads - there will be trouble.
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#124Having 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…
For future walls, try a Cornish hedge. Despite the name, these are actually dry stone walls with an earth core. Mature ones are normally covered in wildflowers. Here's how they're made. http://www.cornishhedges.co.uk/PDF/building.pdf
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#125Earlier quoted context omitted.
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…
Why not do a stones-wall like in the article, but add cement as glue between the rocks?
The wall will then dam up water or crack instead of shifting slightly, I read in another comment.
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#126Earlier quoted context omitted.
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…
Why not do a stones-wall like in the article, but add cement as glue between the rocks?
I did this for a landscaping project because I was not confident enough that it will stay ..lasted ten plus years and then it started cracking. I am now left with unsightly gray blotches and worried the rest might tumble..
It was/is gorgeous..I did three sections ..mostly for three very large kidney shaped raised beds..moss has grown over the stone and I also tried sticking thyme and mint in some of the suitable gaps..
I guess it’s diff if it’s enclosed and filled with soil. I wish i had the confidence and skill to attempt an actual wall.
I used to drive past a house here where the guy took like three years to complete a 80 ft long dry wall and he planted all kinds of beautiful flowering plants ..it was stunning and when it was done, the flowers and fruit trees popped up with their colours too ..it took forever but he didn’t care..you could tell that it was a labour of love and he was really enjoying it.
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#127Earlier quoted context omitted.
> You could stop water draining through the retaining wall and turn it into a dam, which will not end well. Which is why gravel backfill with a perforated pipe at the base (that drains to day light) is specified by many/most building codes.
So what you're saying is we made a problem for ourselves, and then we hacked on additional cost (and plastic) to fix it? I'm starting to see the advantages of this dry stone wall technique.
A 'sealed' retaining wall where the stones are interlocked or even glued/mortared together would probably have a higher load capacity than one made dry/unadhered. Or someone could simply like the aesthetic of a more 'filled in' wall, regardless of practical considerations.
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#128[dead]
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#129Show it still standing in a year and I'll be more impressed.
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#130Earlier 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…
> 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.
Random boulders surely have some guaranteed maximum strength. Now minimum strength is the real problem.