Yet Another Cycling Forum
General Category => The Knowledge => OT Knowledge => Topic started by: mrcharly-YHT on 11 May, 2024, 11:58:35 am
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My step daughter had some building work done by builders who went bankrupt before completing it.
She and her partner are concerned about a gabion basket wall, which doesn't seem vertical.
https://photos.app.goo.gl/byQKVJwjjfxPfpmn7 (https://photos.app.goo.gl/byQKVJwjjfxPfpmn7)
(https://lh3.googleusercontent.com/pw/AP1GczM3yvE3dBvLhz-QUMAbM8XKYk_13E68-NsfT6o5fs3LU3zyhvWh9wGAZQNLk3BNZarrgubSNHdfStceXBKOKnkddaK1C5WB5SL03A9eTsLpRhRtmVWHHBMdM79F1S4vkR67nZBx8r5o6mtsLQnwox1t=w659-h879-s-no-gm?authuser=0)
Is this a cause for concern?
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In my opinion - yes . . the stones tend to "settle" a bit over time and look likely to fall away from the wall. BUT what is the gabion doing, it seems an odd place to have something that high?
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The wall you can see ends just before the gabion.
The bankrupt 'builder' excavated back from there along the side of the house. they put a DPM down the side of the house (which has full height cellar), then backfilled. At the downside they used gabion baskets as a retaining wall. You can get an idea of the slope involved from the wall and window visible; that is the cellar exit into the garden.
I don't know if they've tied the gabions back to anything, or even put hardcore under them. This house is 600miles away from me, so difficult to go and check.
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So the gabion wall is retaining soil to a fair height (>1.5m)? Usually gabion retaining walls step back as they get higher. Gabions are very rarely tied back to anything, relying instead on self-weight for stability.
The CoG of the gabion wall is still very close to the middle of the section so a little lean outwards might not be a big deal but the amount of soil pressure it is resisting is the question.
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Closer to 3m :(
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Soil pressure is still probably fairly low. If so, unlikely to be an issue but I am not speaking on the basis of knowledge and this does not constitute engineering advice.
https://www.gabionbaskets.co.uk/gabion/gabion-wall-standard-design gives some general guidance.
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Bellegarde Airport near Limoges has a magnificent tall gabion wall:
(https://wikiwandv2-19431.kxcdn.com/_next/image?url=https:%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fthumb%2F5%2F59%2FA%25C3%25A9roport_Limoges-Bellegarde2.JPG%2F1500px-A%25C3%25A9roport_Limoges-Bellegarde2.JPG&w=1920&q=50)
As can be seen the stones have been quite carefully arranged to give the structure inherent stability, not just tipped into the basketwork. This obviously takes time, and as we know, time costs money.
The wall seems to be a very good way of protecting the interior of the building from heat.
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Having recently spent several weeks installing gabions as part of our coastal sea defences, I can attest that the time-consuming part was filling the cages in such a way as to minimise settling and slumping, particularly relevant as they are bashed by north-sea waves daily.
Unlike some of our neighbours (which have sagged and bulged) I filled by hand, placing flat-edged stoned to the sides and angled irregular ones to the centre, infilling with smaller stones to fill gaps. I also installed back-to-front bracing/tensioning cables at regular intervals - roughly every 50cm.
After lacing up the cages (they arrived flat-packed), filling them & lacing closed my hands were wrecked!
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Definitely a job that requires gloves.
Thanks for the feedback.
I'm very concerned that these baskets might have been installed directly on soil. The garden slopes away steeply from that point.
Will suggest to daughter that they set up a 'creep stick' or similar so they can tell if the baskets are moving.
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Definitely a job that requires gloves.
I got through several pairs ;) When lacing you're limited in glove thickness by still being able to push & pull the wire where it needs to go.
Agree that having a solid base is probably important. I spent a couple of days compacting and levelling and pretty much got down to bedrock.
As I say our neighbours' baskets were filled by chute with very little manual re-arrangement - and it shows!
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Just been told that they think the baskets were put on the concrete footing of the previous walls. That a bit reassuring.