Driving over Buried Drainage

[Woodsman603]

I'm smack in the middle of a drainage project in the backyard. Got a 100' trench dug 2.5' deep. Laying 1 1/2" stone, fabric, more stone, 4" perforated PVC (green stuff), and finally more stone all the way to the surface. Going to leave the stone exposed.

The dirt from the trench I need to move with the FEL. But, I need to be able to drive over the trench to access the dirt. I think I'm going to end up crushing the PVC if I drive over it. That correct?

L3710 with a Woods9000 Backhoe.

 

[riptides]

I'm smack in the middle of a drainage project in the backyard. Got a 100' trench dug 2.5' deep. Laying 1 1/2" stone, fabric, more stone, 4" perforated PVC (green stuff), and finally more stone all the way to the surface. Going to leave the stone exposed.

The dirt from the trench I need to move with the FEL. But, I need to be able to drive over the trench to access the dirt. I think I'm going to end up crushing the PVC if I drive over it. That correct?

L3710 with a Woods9000 Backhoe.

At 2 feet deep? and probably 6 inches wide (you don't say) I doubt you would harm it with a perpendicular drive over.

 

[4570Man]

That green pipe will survive driving pretty much anything over it with 2’ of cover.

 

[WranglerX]

How about doing proper fill wide enough to accept tractor, and "cross over" and work from dirt pile side.....

Dale

 

[bearthebruce]

If the pipe is fully surrounded by the stone and that stone has been compacted and tamped, I would expect it would carry the weight - like a culvert pipe would carry...

You did not mention the width of the trench - 20" or so? Can you cross the finished trench at an angle such that only one wheel at a time is crossing the trench? That would minimize the risk further.

Mind, everything I say is based on my engineering thoughts and not practice. I have never built a drainage ditch... So, factor that into your thinking...

 

[Woodsman603]

Sorry, width of the trench is ~18"; give or take.

 

[Woodsman603]

I can drive at an angle, sure.

Huh. I thought for sure the tractor would crush that PVC like a lobster claw.

 

[Woodsman603]

How about doing proper fill wide enough to accept tractor, and "cross over" and work from dirt pile side.....

Dale

Not really an option where the trench is. I'm right on the wood line with a decent slop. I can't really access it without clearing a bunch of trees or climbing a very steep incline. There's just enough room to have the dirt piled, and that's it. I can't even get the tractor fully onto the other side of the ditch.

It wasn't until I was done digging the trench that I stepped back and thought to myself, "oh, crap".

 

[bearthebruce]

..... and thought to myself, "oh, crap".

We've all had those moments!

 

[kthompson]

If you are worried take some oak planks and lay across the trenches.

 

[Woodsman603]

If you are worried take some oak planks and lay across the trenches.

Yawp. That was the plan too. I may be able to skirt the edge of the ditch before the PVC starts. If I had to, wood plank would on the ground.

 

[Diggin It]

I'm not sure I'm getting your question. Are you asking about an open trench? Or after it's filled in?

 

[Woodsman603]

I'm not sure I'm getting your question. Are you asking about an open trench? Or after it's filled in?

After its filled in. I'm worried the 1 1/2" stone will crush the PVC when I drive over it. I'm leaving the top of the trench exposed; I'm not covering with dirt. So the rocks will be right up to the grass.

 

[Diggin It]

OK, 'twere it me ..... I'd lay something in the trench before the rock. Some finer grade of gravel, more like coarse sand. That would mean wrapping the perforated pipe in cloth to prevent the smaller grain product from intruding.

Is this 1-1/2 stone crushed rock with sharp edges, or rounded gravel, river rock? The reason I ask is that our county water department has been busy repairing leaks/ruptures in some of their larger pipes because sharp rocks have penetrated the pipes. You don't want sharper rock in direct contact with buried pipe if you can avoid it.


You'll also be cussing that plan when you start spitting rocks out the side of your mower, propelled at relatively high speed by rotating blades.

 

[Woodsman603]

OK, 'twere it me ..... I'd lay something in the trench before the rock. Some finer grade of gravel, more like coarse sand. That would mean wrapping the perforated pipe in cloth to prevent the smaller grain product from intruding.

Is this 1-1/2 stone crushed rock with sharp edges, or rounded gravel, river rock? The reason I ask is that our county water department has been busy repairing leaks/ruptures in some of their larger pipes because sharp rocks have penetrated the pipes. You don't want sharper rock in direct contact with buried pipe if you can avoid it.


You'll also be cussing that plan when you start spitting rocks out the side of your mower, propelled at relatively high speed by rotating blades.

Just rough rock. I may order river stone later on. That's more of a specialty thing. But yea, the jagged rock into the pipe is what concerns me.

Plan is 1 1/2" stone, then fabric. Thin layer of stone, 4" PVC wrapped in the fabric. PVC will also have a sock on it. So I'll have like two layers of fabric.

<Trench<Stone<Fabric<Stone<Sock<PVC>Sock>Stone>Fabric>Stone>Trench

^^if that makes any sense.

As for mowing, not really a big deal. Its in a place we don't really use that much. I'm spitting rocks anyways because our driveway is gravel and every time I plow snow, rocks end up in the yard anyways.

 

[Thunder chicken]

i have a 4" drain in a trench just like you described, up and across my driveway and parking area to take water away. it's been drivin over for 5 years now. and it's not 12" deep, so you'll be fine!
A guy i once knew...... had a piece of 4" drain tile exiting a septic tank, across a yard and roadway that big rigs drive across all year long. Not legal but it works, and it keeps on draining!!

 

[4570Man]

I can drive at an angle, sure.

Huh. I thought for sure the tractor would crush that PVC like a lobster claw.

I’ve drove my 6500 dump truck loaded to 30,000 over the lesser grade schedule 20 PVC with only 12” or so cover and they survived.

 

[Woodsman603]

No kidding. wow. ok then, I'll still try to avoid if I can, but I feel more comfortable if I do end up having to go over it then. I thought for sure that thing would just collapse.

 

[bearthebruce]

I thought for sure that thing would just collapse.

I don't see how it can if it is fully surrounded by gravel and such, the pipe cannot deform. If the sides cannot move outward towards the wall of the trench, the pipe should take the weight.

I had not thought about the coarse pointed stone penetrating the pipe until someone mentioned it here. I think that could be a fail. As that person suggested, finer materials surrounding the pipe would eliminate that problem.

I have read a bunch on dropping in culvert pipe... how tos and so on.. The key to keeping the pipe from collapsing, is to make sure the pipe cannot move. The bottom must be well supported. The sides must be fully supported and all needs to be tamped every couple of inches as the the trench is filled.

As said in my earlier post, never done but we have 3 or 4 culverts planned.. I wanted to know how the big boys do this stuff! Had the same concerns you do until I saw the engineering behind how to make it work.

We have two culverts now on the half mile driveway up the mountain. Big trucks hauling trees off the property have gone across with no issues. The guys who put those in did not spend the time I am spending overthinking all this! But then, when a newbie, I like to know all I can know before I dive in. I think you are like me.

 

[MechanicalGuy]

All my research indicates that abs should be used instead of pvc for crush resistance. Maybe you're buried deep enough to not be a concern though.