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Civ Eng graduate that ended up in IT here. For home projects, please consider gabions as well as the usual suspects when you are building retaining walls. A g

Civ Eng graduate that ended up in IT here. For home projects, please consider gabions as well as the usual suspects when you are building retaining walls. A gabion is a galvanised steel wire cage say: 4' x 4' x 2' (HWD). They have a hinged lid and you fill them with stones and then wire the lid shut. Sounds stupidly simple, and it is but they have some rather useful properties. Each unit is an easy one man lift, place and fill. Once filled, each one nominally becomes a large single block with great drainage properties. You can wire these things together into long rows. They work very well with water courses because they are easy to fix in place and once filled, won't move. Pouring conc. into formwork is a right old pain in a fast flowing river and it is all too easy to lose the finer particulates before the stuff has gone off (set and cured). You can finish the exposed surfaces in various ways. You can pour soil on top and grass them, pour a bit of low grade conc and gravel for a solid "path". The cages are not particularly pretty but neither are they particularly ugly. If a single cell fails then it generally won't cause much surrounding failure and is easy to replace or repair. You can embed fancy anchors inside them if you have a lateral thrust to resist that can't be dealt with by sheer mass. Sleepers and the like are quite convenient but you must consider drainage otherwise they will rot within a few decades. Block backed brickwork needs a decent brickie to lay them and if they fail it is usually rather bad. I'm no brickie but I've just repaired a broken 3' retaining wall at home and it looks a bit shit. I will be hiring a professional to sort it all out in spring. Here a gabion wall is overkill! I did say home projects above but these things are used everywhere and that includes some pretty huge retaining structures. If you are not a Civil Engineer and need to build a decent sized retaining structure then I highly recommend that you consider gabions first because you are far more likely to get it right first time.

FooHentai 5y ago
They seem to have become vogue for decorative purposes in the last few years, for stuff like bbq pit walls, windbreaks, and those faux gateway entrances that have no fenceline around them. Personally I think they look very ugly, and the trend is a bit of a mystery.
- gerdesj 5y ago
  Ugly - probably but they are rather clever in my opinion. They are modular and can be deployed by one bod nearly anywhere. I have no idea what windbreaks and faux wotsits are let alone "decorative" means. I'm a bodger/Engineer. If you need to stop a vast amount of stuff moving from A to B then gabions are a very decent solution with the added bonus that you don't need to be an Engineer. Civilians will generally get it right first time just by looking at the problem.
- jmacd 5y ago
  This is not the case where I am in Canada, but your comment caused me to check Google Images. https://www.google.com/search?q=gabion+wall https://www.google.com/search?q=gabion+wall What is going on here? This is a totally bizarre architectural element.
- iancmceachern 5y ago
  I've started to see this everywhere also
- pgreenwood 5y ago
  Fair enough, many are ugly, but I generally quite like the way they look. Lots of scope for different shapes and colours and textures. They can be blended in with the local geology via the choice of rocks. You can put benches or pathways on them, or soil on them and grow plants, or even grow mosses and lichens.
iampivot 5y ago
They can be made a bit prettier by using flat sided rocks and line the front of the wall with rocks that seems to interlock a bit. Any round rocks that will not make a flat wall go in the back.
Retric 5y ago
That sounds like a retaining wall failure waiting to happen. Thin galvanized cages are providing short term structure, but they have relatively short lifespan underground. Fine for knee high walls, but if your covering it with soil it’s not obvious these these things are going to become unstable.
- ethbr0 5y ago
  Apparently the answer is "it depends on the soil chemistry." DURABILITY OF REINFORCED EARTH STRUCTURES: THE RESULTS OF A LONG-TERM STUDY CONDUCTED ON GALVANIZED STEEL. M DARBIN, JM JAILLOUX, J MONTUELLE, and ROMANOFF Proceedings of the Institution of Civil Engineers 1988 84:5, 1029-1057 https://www.icevirtuallibrary.com/doi/abs/10.1680/iicep.1988.508 https://www.icevirtuallibrary.com/doi/abs/10.1680/iicep.1988... (pay article) Others here https://scholar.google.com/scholar?q=galvanized+soil https://scholar.google.com/scholar?q=galvanized+soil The following appear to be true: (1) HDG (or equivalent) has an order of magnitude greater resistance to corrosion in soil than uncoated steel, (2) corrosion rates are highly influenced by presence (or lack) of chlorides, sulfate, and citric acid in the soil, as well as temperature. Given the above, the suitability of galvanized steel in soil, at standard steel diameters and coating thicknesses, is either suitable (for low aggressivity soils) or non-suitable (for high aggressivity soils) over an example span of 20 years. Tl;dr: test and characterize the soil it's going to be in.
  - Retric 5y ago
    20 years is an extremely short benchmark, but just long enough for people to forget about it thus the danger.
    - ethbr0 5y ago
      By that metric, 40 years would be even worse.
- gerdesj 5y ago
  I'm 51 years old. I built one to stop bank erosion in a stream at a change in level and direction at my parent's house about 30 years ago. All units are fine. They sit at least 1/3 height in water all the time and have soil/subsoil behind. They have a thin pour of mortar with gravel on top to make a path and have integrated into the bank and grass. Galvanized steel is surprisingly rust resistant and that's the key. These gabions do get quite a bashing when it rains hard. The stream in question is in Devon, Woodbury (Salterton), near Exeter (UK), which is popple land. Popples are rounded stones found in the streams thereabouts. They make ideal gabion fill. They also destroy things downstream if the flow is fast enough to rouse them! That's one case study that I've chosen deliberately to show that they work for DIY.
njarboe 5y ago
How long to they last if they are not underwater but moist all the time? I would think that if you are retaining soil, it will be always moist in many/most climates or where one is watering landscape above.
- gerdesj 5y ago
  See my comment above. I built one 30 odd years ago at my parent's house. It is still fine and looks as good as when I built it. The key thing is: galvanized.
  - njarboe 5y ago
    They probably make them in stainless steel too, if you don't mind the shiny aesthetic.
dredmorbius 5y ago
Gabions are shown at 2:32 in the video (and a few other points).
robomartin 5y ago
> For home projects, please consider gabions Not sure these are permitted in LA Country. Having tangled with the permit office before, I know just how ugly it can get (brutally ugly!) to try to do something they don't have a checkbox for. I can see them for decorative purposes (a firepit or bbq island). Even then, one of the problems we have out here is that you are guaranteed to have all kinds of insects make a home out of a pile of rocks. We have nice ones, like black widows, that you really don't want anywhere you are going to be walking around in flip-flops. Interesting look though. https://dpw.lacounty.gov/bsd/lib/fp/Building/Residential%20Code%20Manuals/2011/RCM%20R404.4%20A1%20-%20Design%20of%20Retaining%20Walls%2010-25-12.pdf https://dpw.lacounty.gov/bsd/lib/fp/Building/Residential%20C...
jaclaz 5y ago
I would add that gabions being "loose" have an additional usefulness as they are very flexible and allowing differential land movements (which are often the cause of cracks and instabilities in more rigid structures) and are thus a good anti-sismic structure. About duration, at least here (Italy) they are usually considered in the 100 years duration range, not unlike many other kinds of structures. The inherent draining is the clearest advantage when compared to other solutions (make sure to use some geotextile behind them to "filter" small particles) , though - to be fair - they do need more space than other kind of walls and they rapidly become unusable when you go over 3-4-5 meters height.

FooHentai 5y ago

They seem to have become vogue for decorative purposes in the last few years, for stuff like bbq pit walls, windbreaks, and those faux gateway entrances that have no fenceline around them. Personally I think they look very ugly, and the trend is a bit of a mystery.

gerdesj 5y ago
Ugly - probably but they are rather clever in my opinion. They are modular and can be deployed by one bod nearly anywhere. I have no idea what windbreaks and faux wotsits are let alone "decorative" means. I'm a bodger/Engineer. If you need to stop a vast amount of stuff moving from A to B then gabions are a very decent solution with the added bonus that you don't need to be an Engineer. Civilians will generally get it right first time just by looking at the problem.
jmacd 5y ago
This is not the case where I am in Canada, but your comment caused me to check Google Images. https://www.google.com/search?q=gabion+wall https://www.google.com/search?q=gabion+wall What is going on here? This is a totally bizarre architectural element.
iancmceachern 5y ago
I've started to see this everywhere also
pgreenwood 5y ago
Fair enough, many are ugly, but I generally quite like the way they look. Lots of scope for different shapes and colours and textures. They can be blended in with the local geology via the choice of rocks. You can put benches or pathways on them, or soil on them and grow plants, or even grow mosses and lichens.

iampivot 5y ago

They can be made a bit prettier by using flat sided rocks and line the front of the wall with rocks that seems to interlock a bit. Any round rocks that will not make a flat wall go in the back.

Retric 5y ago

That sounds like a retaining wall failure waiting to happen. Thin galvanized cages are providing short term structure, but they have relatively short lifespan underground. Fine for knee high walls, but if your covering it with soil it’s not obvious these these things are going to become unstable.

ethbr0 5y ago
Apparently the answer is "it depends on the soil chemistry." DURABILITY OF REINFORCED EARTH STRUCTURES: THE RESULTS OF A LONG-TERM STUDY CONDUCTED ON GALVANIZED STEEL. M DARBIN, JM JAILLOUX, J MONTUELLE, and ROMANOFF Proceedings of the Institution of Civil Engineers 1988 84:5, 1029-1057 https://www.icevirtuallibrary.com/doi/abs/10.1680/iicep.1988.508 https://www.icevirtuallibrary.com/doi/abs/10.1680/iicep.1988... (pay article) Others here https://scholar.google.com/scholar?q=galvanized+soil https://scholar.google.com/scholar?q=galvanized+soil The following appear to be true: (1) HDG (or equivalent) has an order of magnitude greater resistance to corrosion in soil than uncoated steel, (2) corrosion rates are highly influenced by presence (or lack) of chlorides, sulfate, and citric acid in the soil, as well as temperature. Given the above, the suitability of galvanized steel in soil, at standard steel diameters and coating thicknesses, is either suitable (for low aggressivity soils) or non-suitable (for high aggressivity soils) over an example span of 20 years. Tl;dr: test and characterize the soil it's going to be in.
- Retric 5y ago
  20 years is an extremely short benchmark, but just long enough for people to forget about it thus the danger.
  - ethbr0 5y ago
    By that metric, 40 years would be even worse.
gerdesj 5y ago
I'm 51 years old. I built one to stop bank erosion in a stream at a change in level and direction at my parent's house about 30 years ago. All units are fine. They sit at least 1/3 height in water all the time and have soil/subsoil behind. They have a thin pour of mortar with gravel on top to make a path and have integrated into the bank and grass. Galvanized steel is surprisingly rust resistant and that's the key. These gabions do get quite a bashing when it rains hard. The stream in question is in Devon, Woodbury (Salterton), near Exeter (UK), which is popple land. Popples are rounded stones found in the streams thereabouts. They make ideal gabion fill. They also destroy things downstream if the flow is fast enough to rouse them! That's one case study that I've chosen deliberately to show that they work for DIY.

njarboe 5y ago

How long to they last if they are not underwater but moist all the time? I would think that if you are retaining soil, it will be always moist in many/most climates or where one is watering landscape above.

gerdesj 5y ago
See my comment above. I built one 30 odd years ago at my parent's house. It is still fine and looks as good as when I built it. The key thing is: galvanized.
- njarboe 5y ago
  They probably make them in stainless steel too, if you don't mind the shiny aesthetic.

dredmorbius 5y ago

Gabions are shown at 2:32 in the video (and a few other points).

robomartin 5y ago

> For home projects, please consider gabions Not sure these are permitted in LA Country. Having tangled with the permit office before, I know just how ugly it can get (brutally ugly!) to try to do something they don't have a checkbox for. I can see them for decorative purposes (a firepit or bbq island). Even then, one of the problems we have out here is that you are guaranteed to have all kinds of insects make a home out of a pile of rocks. We have nice ones, like black widows, that you really don't want anywhere you are going to be walking around in flip-flops. Interesting look though. https://dpw.lacounty.gov/bsd/lib/fp/Building/Residential%20Code%20Manuals/2011/RCM%20R404.4%20A1%20-%20Design%20of%20Retaining%20Walls%2010-25-12.pdf https://dpw.lacounty.gov/bsd/lib/fp/Building/Residential%20C...

jaclaz 5y ago

I would add that gabions being "loose" have an additional usefulness as they are very flexible and allowing differential land movements (which are often the cause of cracks and instabilities in more rigid structures) and are thus a good anti-sismic structure. About duration, at least here (Italy) they are usually considered in the 100 years duration range, not unlike many other kinds of structures. The inherent draining is the clearest advantage when compared to other solutions (make sure to use some geotextile behind them to "filter" small particles) , though - to be fair - they do need more space than other kind of walls and they rapidly become unusable when you go over 3-4-5 meters height.