Retaining wall questions - sleeper design

[jason61c]

Hi all.

I've 22M of retaining wall do build, 1.2m above ground level.

I looked at blockwork, then rendered but wasn't keen on the look.

So i'm going to go for untreated hardwood railway sleepers, 2.6m x240x150. Supported with I beams. I was going to do them vertical, however would a 5deg towards the garden be a better idea?

How much beam should go into concrete? 600mm? Has anyone got any other ideas or thoughts?

Thanks in advance.

 

[mikeey84]

1.2m above ground level.

I'm no expert, but I am fairly sure that a retaining wall that high should be designed by a structural engineer due to the potential crush

 

[jason61c]

I'm no expert, but I am fairly sure that a retaining wall that high should be designed by a structural engineer due to the potential crush

I don't think they do at this height? Its retaining soil, no heavy traffic, just garden. I could just shape bank and it wouldn't move, in theory

 

[Sunshine12]

I have something similar 800mm high. The sleepers I have are 200mm when lay on side, otherwise 100mm when lay flat. Think 2.4m long. 100x200x2400

Could you get a similar size then lay them horizontally, so that would 6 sleepers stacked (staggered joints) 6 @ 200mm = 1.2m, bolted through with HD coach bolts & 4 inch posts season spaced say every metre.

Then fill the retainer with hardcore & slab.

Use the sleepers for steps too?

 

[Halitosis]

I built a 1.2m retaining wall using those mortar-free blocks (Tobermore) - not cheap but at least easy enough for an amateur like me. I investigated the legalities regarding structural engineer, and this was the height limit (assuming not near a building or road as you say). Your sleeper idea sounds great - how about laying them horizontal but at a 5 degree angle to the face (Sunshine's excellent coach bolt suggestion could still be applied).
Whatever you choose, drainage is critical - lay a field drain behind in pea-gravel with an outlet.

 

[jason61c]

The plan was for i beams(£40 each) to hold 5 beams on their side, I think that'd be stronger than bolting them? effectively every 2.6m i'd have an I beam.... Could I do without the beams and just bolt and stack?

 

[jason61c]

I built a 1.2m retaining wall using those mortar-free blocks (Tobermore) - not cheap but at least easy enough for an amateur like me. I investigated the legalities regarding structural engineer, and this was the height limit (assuming not near a building or road as you say). Your sleeper idea sounds great - how about laying them horizontal but at a 5 degree angle to the face (Sunshine's excellent coach bolt suggestion could still be applied).
Whatever you choose, drainage is critical - lay a field drain behind in pea-gravel with an outlet.

How did the tobermore's go? where did you get them from and what price? Seems like a decent solution?

 

[Halitosis]

How did the tobermore's go? where did you get them from and what price? Seems like a decent solution?

Fantastic Jason. My wall is 15m long in total x 1.2m high (though I raised the patio so a little less visible). Building it was simple, even for a complete novice like me, as long as you get the base and first course of blocks level, its like lego from then on. 3 years later and it still looks as good as the day I finished it.
Just looked up the invoice and I paid £7.55/unit... I think the "unit" was 1 linear metre of blocks and it totalled a little under £2k including VAT and coping. Secura Lite in Bracken. Some images are in this thread https://www.diynot.com/diy/threads/garden-levelling-retaining-walls-and-patio.436119/#post-3613497. I would have paid a similar price to get a tradesman to supply and build rendered blockwork, and I think the Secura looks much better. Also as its not mortared, it allows water through in the event of heavy rainfall, and (theoretically) if we ever move house I can disassemble the wall and take it with me

 

[jason61c]

Thanks, although its now about £2.7k, so about £1000 more than sleeper materials, plus the extra work needed for the wall base etc.

I do like the idea of taking them with you

 

[ger83]

We built this retaining wall with sleepers laid vertically, 720mm high. They are secured to the existing fence posts (after shaving off some of the concrete base) since they were deep enough. Where the joins didn't match the existing fence posts we drove an offcut down the back to pack it out.

Previous owners built the brickwork but the top area still sloped towards the fence. We leveled it and put in the sleepers. Had no issues.

 

[jason61c]

So as an update....

Take 68 of these

19 of these

lots of this

Then build like this

Then end up with this..... still work to finish

https://imgur.com/a/cprZg2W

https://imgur.com/a/cprZg2W

 

[jason61c]

Took 9 days.

35m of new drains/5 inspection chambers-man holes
45 linear m of walls or more
40 tonne of concrete buried
150sq m of turf
20 steel i beams
20 tonnes of 803
68 azobe sleepers at 90-120kg each
3 tonnes of ballast
12 bags of cement
4 tonnes of pea gravel
2 tonnes of sand
100sq of geotex
25m of land/french drain.

 

[Halitosis]

I bet the beer tasted good at the end of that... huge project - congratulations sir!

 

[jason61c]

It did. Picked a nice hot week for it