Repairing large steel culvert pipe

[Too_Old_For_This]

Is there any way to repair a galvanised steel culvert pipe, they're about 1m in diameter, 30m long and the bottoms are rusting through. Normally we'd just take them out and replace but these are next to the farm house with all manner of stuff in the way - tanks, sheds...We were thinking of lining the bottom with cement but I reckon that'll get washed away in a flood - which seems to happen more often nowadays! Has anyone successfully repaired one? Any advice gratefully received!

 

[Lofty1984]

Can you line the base with another pipe cut lengthways in half and screwed to the existing and then a concrete plinth on the inlet to stop water getting between the two

 

[Bury the Trash]

'simply' line with twin wall would 6m lengths of 1020mm OD slide through ?

 

[Dry Rot]

'simply' line with twin wall would 6m lengths of 1020mm OD slide through ?

Not as long but my access road runs over a culvert constructed from (I think) three large spun concrete pipes. Those pipes are very expensive and the culvert was just too narrow for anything but a mall lorry and farm traffic. So I just pushed a plastic pipe through (as the flow is very slow) and built the ends up. Now my dear sweet neighbour is using the access to bring artic loads of timber in to process for firewood, so I am hoping the ends will fall in, but that's another story! My own fault for making such a good job of it.

 

[Bury the Trash]

Not as long but my access road runs over a culvert constructed from (I think) three large spun concrete pipes. Those pipes are very expensive and the culvert was just too narrow for anything but a mall lorry and farm traffic. So I just pushed a plastic pipe through (as the flow is very slow) and built the ends up. Now my dear sweet neighbour is using the access to bring artic loads of timber in to process for firewood, so I am hoping the ends will fall in, but that's another story! My own fault for making such a good job of it.

yes a bit dependent on maximum flow rates and
its not quite so good as digging the trench and putting in pipe with pipe bedding nicely packed around,plastic will take a decent weight then

dont want any eroding in under or anywhere inside tho. of course

 

[ARW]

I think pushing a smaller twin wall pipe in is the cheapest long term solution

 

[Dry Rot]

yes a bit dependent on maximum flow rates and
its not quite so good as digging the trench and putting in pipe with pipe bedding nicely packed around,plastic will take a decent weight then

dont want any eroding in under or anywhere inside tho. of course

If the steel pipe hasn't collapsed (?), would that not spread the load? I know I over thought my problem and it turned out to be quite easy, but I can't remember how I got the plastic pipe through. I think I scoured the original pipe of as much debris as I could, then pulled it through. Ferret, string, and dead rabbit? Sounds like a Dry Rot solution!

 

[Bury the Trash]

If the steel pipe hasn't collapsed (?), would that not spread the load? I know I over thought my problem and it turned out to be quite easy, but I can't remember how I got the plastic pipe through. I think I scoured the original pipe of as much debris as I could, then pulled it through. Ferret, string, and dead rabbit? Sounds like a Dry Rot solution!

ha,ha i know you dont mean it that way, butnow ive got visions of a poor little downcast ferret scrabbling and struggling to haul a great long piece of pipe by a piece of string,

osma type soild wall plastic pipe is stronger than twin wall and would slide in better and allow settlment around it better, but it wont be got in that size nd even smallr is deaer than twin wall.

GRP pipe can be got is strong and smoother (but theres still the extra diameter joins as in osma to allow for) if you can find it secondhand or something but again new it would cost $ S

 

[Dry Rot]

ha,ha i know you dont mean it that way, butnow ive got visions of a poor little downcast ferret scrabbling and struggling to haul a great long piece of pipe by a piece of string,

osma type soild wall plastic pipe is stronger than twin wall and would slide in better and allow settlment around it better, but it wont be got in that size nd even smallr is deaer than twin wall.

GRP pipe can be got is strong and smoother (but theres still the extra diameter joins as in osma to allow for) if you can find it secondhand or something but again new it would cost $ S

I have actually to start thinking about a similar job as I have about 50m of drainage pipe that seems to have been blocked with tree roots. The original pipe was plastic conduit about 300m diameter. I think I am just going to have to get it dug out and twin wall laid, but it would only need to be about 100mm diameter. I tried to clean it out with drain rods with the half moon scraper on the end but it got stuck and won't go forwards or backwards now. Any bright ideas (excluding the ferret)? I'm thinking rope and tractor and if something breaks, it breaks.

 

[Too_Old_For_This]

Morning, thanks for all the replies.

No the existing steel pipe hasn't collapsed...yet, it's just rotted through the base on about 20mm of it - probably because of the amount of gravel that comes down the stream in a flood.

I was thinking about "lining" with a slightly smaller twin wall. I think we'll be ok on flow rate, the culvert is x2 1m diameter pipes and so far I've never seen them more than 2/3rds full. I did wonder if I would need to fill the void between the old and the new to give it some support...god only knows how you'd inject inbetween the two but I supose if the steel is still structurally sound then I may not need to do that. I can see it being a pain to get a new pipe down the old, Dry Rot, I'll drop you a line see if I can borrow that Ferret, string, and dead rabbit method!

I'll let you know how we get on

 

[Dry Rot]

Morning, thanks for all the replies.

No the existing steel pipe hasn't collapsed...yet, it's just rotted through the base on about 20mm of it - probably because of the amount of gravel that comes down the stream in a flood.

I was thinking about "lining" with a slightly smaller twin wall. I think we'll be ok on flow rate, the culvert is x2 1m diameter pipes and so far I've never seen them more than 2/3rds full. I did wonder if I would need to fill the void between the old and the new to give it some support...god only knows how you'd inject inbetween the two but I supose if the steel is still structurally sound then I may not need to do that. I can see it being a pain to get a new pipe down the old, Dry Rot, I'll drop you a line see if I can borrow that Ferret, string, and dead rabbit method!

I'll let you know how we get on

By coincidence, I do have a suitably qualified and experienced ferret available on contract. Just not sure how we would manage with the current C-19 restrictions....

As for the pipe, if you could get one down the inside of the original, I'd just let the water sort it out. It will surely find its own way out the other end?

 

[DrWazzock]

Fill the gap with a quick setting liquid cement based grout to help spread the load round the liner?

 

[milkloss]

On smaller pipe but I used expanding foam between old and new, seemed to like the damp to bond and set

 

[Dry Rot]

Why fill the gap? The downward forces are going to be spread over a fairly wide area. I bet you'd have difficulty crushing the steel pipe as it is with anything less than some sort of spike to concentrate the pressure on one small area. How easy it to crush a plastic drainage pipe when under even a few inches of gravel?