Retaining wall advice

[Monkeybusiness]

don't think they'd be up to a retaining role .... more stress free walling, but if there ain't a lot behind 'em they'd make a lovely walls

They use them as walls for silage clamps and grain stores - there is a curve to them so they have a ‘strong’ side (for pushing against). No reason that couldn’t be reversed to retain soil etc but I guess you would need to be careful then pushing against the ‘weak’ side (which shouldn’t be an issue if the strong side is actually retaining something).

 

[Stroppymonkey]

do you have a good source for the concrete sleepers - make excellent roads/hard standings too, if you prep right

Dad is very fond of them. All the gate posts/receivers/strainers everywhere are being replaced with them. Personally I think C Section Crash barrier would be better and easier. But to be fair the concrete posts will last damn near forever. Not sure where he got the last lot from.

 

[DaveDCB]

Actual concrete panels aren’t expensive for what they are - you could have them 20 feet long and use fewer (but bigger) steels.

But at 20ft you’d need 6” panels..

 

[Stroppymonkey]

But at 20ft you’d need 6” panels..

Too heavy/big for me . Spoils the fun if I have to outsource the haulage and lifting !

 

[V8Druid]

They use them as walls for silage clamps and grain stores - there is a curve to them so they have a ‘strong’ side (for pushing against). No reason that couldn’t be reversed to retain soil etc but I guess you would need to be careful then pushing against the ‘weak’ side (which shouldn’t be an issue if the strong side is actually retaining something).

so they must be pre-stressed, specifically for the job, much like floor beams ... all the wall panels I've seen round here are gun barrel straight / flat

 

[Smiffy]

so they must be pre-stressed, specifically for the job, much like floor beams ... all the wall panels I've seen round here are gun barrel straight / flat

Even the flat ones are pre stressed. I've done a few kingpost retaining walls and we always use ones that are symmetrical.
They use cable in them and tension it with hydraulics. Then cast the concrete around the cables and release the tension.
They are plenty strong enough for retaining walls. The kingposts will give out before the panels. We did one that was at 2m centres and 4m in the ground for a 2m high wall in running sand.

 

[Stroppymonkey]

Even the flat ones are pre stressed. I've done a few kingpost retaining walls and we always use ones that are symmetrical.
They use cable in them and tension it with hydraulics. Then cast the concrete around the cables and release the tension.
They are plenty strong enough for retaining walls. The kingposts will give out before the panels. We did one that was at 2m centres and 4m in the ground for a 2m high wall in running sand.

I was thinking 1m in the ground (soft rock) and 2.4 high above ground . Backfill with 40mm recycled concrete

 

[DaveDCB]

Horrible things to work with, it’s not a nice day messing around with them! Heard of a few fellas being killed when lifting conc panels - they demand upmost respect!

 

[Smiffy]

I was thinking 1m in the ground (soft rock) and 2.4 high above ground . Backfill with 40mm recycled concrete

I would think you will need it a bit deeper than 1m. All the ones I've done have been at least as deep as they are tall. 2.4m has the potential to be some serious hydraulic pressure.

Horrible things to work with, it’s not a nice day messing around with them! Heard of a few fellas being killed when lifting conc panels - they demand upmost respect!

Definitely need the correct lifting eyes for the panel. Local lad as far as I understand, lifted one up with chains choked round it, somehow it ended up on top of both his legs.

 

[Lancs Lad]

Horrible things to work with, it’s not a nice day messing around with them! Heard of a few fellas being killed when lifting conc panels - they demand upmost respect!

Not ratchet straps then ? 🫣🫣

 

[Stroppymonkey]

I would think you will need it a bit deeper than 1m. All the ones I've done have been at least as deep as they are tall. 2.4m has the potential to be some serious hydraulic pressure.



Definitely need the correct lifting eyes for the panel. Local lad as far as I understand, lifted one up with chains choked round it, somehow it ended up on top of both his legs.

Will dig a test hole. Its more to give a flat edge than retaining as its mostly virgin rock. Wont be any hydraulic pressure with sleepers (gaps every 300mm) + granular backfill and drainage I shouldn't have thought?

Local concrete panel company had a driver fatally injured and a worker instantly killed a couple years back. Not nice.
Not seen the HSE report yet... assume its still in progress unless I am looking in the wrong place.

One dead and three injured in incident at concrete firm

One person has died and three people have been injured in an incident at a concrete company in Devon that has prompted a Health and Safety Executive (HSE)

www.constructionnews.co.uk

 

[DaveDCB]

Silage pit I took out at home was about 1 meter in ground 2 meters out, each steel had about 2 cube around it.. didn’t move!

 

[Smiffy]

Silage pit I took out at home was about 1 meter in ground 2 meters out, each steel had about 2 cube around it.. didn’t move!

We have only ever done augered holes just big enough to fit the rsj. I can't find the photos of it but one we did the holes where done with a piling rig. 6m deep in chalk in godalming. The 13t couldn't lift the steels in from the ground so it was parked up the top on retained ground.

 

[V8Druid]

I was thinking 1m in the ground (soft rock) and 2.4 high above ground . Backfill with 40mm recycled concrete

and put a perf. drain at the bottom

 

[V8Druid]

Even the flat ones are pre stressed. I've done a few kingpost retaining walls and we always use ones that are symmetrical.
They use cable in them and tension it with hydraulics. Then cast the concrete around the cables and release the tension.
They are plenty strong enough for retaining walls. The kingposts will give out before the panels. We did one that was at 2m centres and 4m in the ground for a 2m high wall in running sand.

yeh I should have said pre-cambered and prestressed - there're a few vids on you tube of them being made and how they stretch the rebars

 

[6feetdown]

and put a perf. drain at the bottom

Solid plastic slotted is better stops fines blocking it up

 

[V8Druid]

Solid plastic slotted is better stops fines blocking it up

yeh - like this stuff - 10" bore IIRC

got pretty adept at laying them 9" hollows after 1200 of 'em ... would never be able to earn a living doing it - too slow - but it won't fall down
impatient 'boss' wanted it flat and green, faster than I could get the bloody wall up

 

[Giles]

Engineer designed will have drawing somewhere we had 1.4m or more into ground about 1m3 per steel in rocky shale

 

[Giles]

Engineer designed will have drawing somewhere we had 1.4m or more into ground about 1m3 per steel in rocky shale

Steels were chunky

 

[V8Druid]

Steels were chunky

203 x 203 x 46 I'd guess at -- I remember you doing that job