| Archive for Downsizer For an ethical approach to consumption |
| Jonnyboy |
Landscaping - anyone seen thisDrove past this on saturday and took a quick snap or two. I've never seen it before but it looks like a good method of bank retention.It looks like one part is hammered into the bank, or a frame constructed and it's back filled. Anyone seen this before and have an idea on it's construction? 
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| tahir |
Looks nice | ||||
| Jonnyboy |
Indeed, I'm hoping it will be a lesser cost option than some other methods as well. | ||||
| Behemoth |
I think it's a frame and then back filled but not sure. Looks better than those bales of rocks. | ||||
| Cathryn |
The one that has been used recentlu by the railway to support banks around each end of a bridge, has had plants rooted into it so it is only a thin layer of rocks behind the wooden retaining fence. | ||||
| Green Man |
What happens when it rots? | ||||
| Jonnyboy |
Dunno, that's why I'm after some advice. | ||||
| tahir |
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| Jonnyboy |
Now we're getting somewhere
http://www.phigroup.co.uk/products/rw/permacrib.htm |
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| Jonnyboy |
You have good contacts, thanks |
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| tahir |
Glad you like em, thought it was about time I got rid of my NHS specs |
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| tahir |
It's actually www.keller-ge.co.uk | ||||
| Behemoth |
or here... http://www.phigroup.co.uk/products/rw/permacrib.htm | ||||
| Jonnyboy |
I've emailed them. I've also found a system which used rammed earth tyres which might be interesting. | ||||
| cab |
Reminsicent of a raised hedgerow in the South West. You'd hope that plants and eventually trees would root into it, holding the structure together as the timber rots away. May even be worth planting a hedge right on top (and in amongst it) to pin the whole thing together. | ||||
| dougal |
I note that Keller call Phi "our sister company", and that they (both) offer a number of other solutions to stabilising steep slopes, including the 'geogrids' for "soil reinforcement" that I've mentioned previously. | ||||
| mochyn |
Gabions. |
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| tahir |
Had anotther couple of responses:
From Germany: Was extensively used but no longer used as trees usually fail due to lack of moisture From NZ: Widely and successfully used, no moisture problems due to higher rainfall. |
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| sean |
Should be OK for jonnyboy then. | ||||
| tahir |
Should be, some concerns were raised at the fact that they use imported radiata pine rather than local sitka | ||||
| Jonnyboy |
I've downloaded some of their plans, it's a bit naughty but I'm thinking of talking to a local sawmill about making it up.
My FIL is a skilled woodworker so he could make templates or samples. |
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| cab |
Look in to the dry stone hedges (usually filled with earth and then ultimately they become great big green mounds) in the South West. I think that aiming to end up with one of those with the structure you're looking at there as a starting point is the way to go. | ||||
| Jonnyboy |
They aren't designed for lateral loads though are they? |
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| Behemoth |
Bocage. Stopped a tank. | ||||
| cab |
You might think not, but look over those hedges at the field on the other side. Might take years, but you end up with a field much higher than the road on the other side, so the load they're taking must be tremendous. I've seen some that are a good six feet and more higher on one side than the other. Ultimately I think the structure you're looking at could end up like that, the difference being that you're starting out with timber supports because the structure has to bear that load from the outset - you could envisage that in, say 10 years it'll be a , hedged over bank with the stones visible and wooden struts sticking out whereas in 30 years time a lot of the wood will be rotted away, and you'll have a grassy, stony bank with hedge growing out of the top. |
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| Behemoth |
or is it the lane that sinks? | ||||
| sean |
The bank gets trodden down by animals, so if it's between fields they stay level. You have to earth them back up every so often. (There's probably a special word for this, but being an immigrant I don't know it). | ||||
| tahir |
Tahir, if you intend to dip your toe into the world of bank stabilisation a
key source book is "Use of Vegetation in Civil Engineering" Coppin and Richards 1991. pub CIRIA/Butterworths ISBN 0-408-03849-7 Dozens of variants on the picture you post, mostly underpinned with exotic looking mathematical equations, and all, at bottom, thoroughly practice based. |
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| Jonnyboy |
Got a quote back, 2.5k for delivery only of the wood, thats' to make a 20m x 1m retaining wall.
What a waste of time, I can do it with railway sleepers for around a third of the cost. |
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| Welsh Girls Allotment |
We have lots of these in the valleys, as everything slopes up the valley sides, mostly they seem to be used for car parking areas at newly developed supermarkets, we also have a huge plataux (sorry minds gone blank I just can't remember how to spell it correctly !)created from this system and it has been there approx 7 years | ||||
| cab |
Both. The level of the field rises if it is manured, farmlands do tend to rise... But either way those dry stone hedges end up supporting a hell of a load. |
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| dougal |
Soil mechanics.
Surely the lateral thrust is going to greatly depend on the soil characteristics? My expectation is that the lateral force is going to be high for things like clay that would tend to flow of their own accord, and that the force would be lower for self stable piles of rock... (hence gabions, etc) Of course it all gets more intense when one considers added loads on the raised ground, and the actions of water... |