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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

#71

Post by schiffern »

throw0101b wrote: post #54
gerdesj wrote: post #24

Earlier quoted context omitted.

"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. Yo…

> 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.

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

#73

Post by 93po »

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…

Now this is gardening I can get behind

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

#74

Post by schiffern »

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…

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 baked yet (and it's hardly a drop-in replacement for reinforced/pretensioned/cantilevered/etc) but for things like heavy infrastructure and civil engineering this might offer a way to achieve fundamental thermodynamic improvements.

Excited to see where this technology goes.

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

#75

Post by TulliusCicero »

dublinben wrote: post #30
ExMachina73 wrote: post #20

Perhaps in hundreds of years they'll be able to deploy AI robots to poorer regions of the world to build basic utilities, mine resources, and even whole cities from nothing. Or have them depoloyed to current cities constantly repairing and optimizing infrastructure.

If there's one thing that lower income countries have an excess of, it's people to perform labor. There's a reason why you don't see countries (e.g. China) introducing more automation until they rise to a certain income level.

Generally you're right, but also

a) You may not have skilled labor easily available for a niche like constructing a dry stone wall out of giant rocks, and

b) sometimes employing that labor via local firms can result in corruption issues.

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

#77

Post by scythe »

gerdesj wrote: post #24
toomuchtodo wrote: post #9

Earlier quoted context omitted.

You 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://www.geostabilization.com/technology/shotcrete-robot/ https://dawinvehicles.en.made-in…

"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. Yo…

I don't understand. You don't need to fully coat the wall with shotcrete in order to stabilize the rocks. There could still be holes.

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

#78

Post by bluGill »

maxglute wrote: post #59
beachy wrote: post #46

Earlier quoted context omitted.

I think this is great tech, but maybe not for those reasons. On any safe site, people are already very cautious and working well back from the excavator. Some teams have a protocol where you have to make eye contact with the digger driver before you can go anywhere within the sweep of its arm.

But without the excavator operator, can you not cram more autonomous excavators to get more work done? Seems like sufficiently good sensors would allow them to work in each others safety zones for parallel work.

Probably not as the soil they ig needs to go someplace. That means dump trucks will still be the majority of the site.
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