Driving over Buried Drainage

Woodsman603 · May 13, 2020

kthompson said:
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 · May 13, 2020

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

Woodsman603 · May 13, 2020

Diggin It said:
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 · May 13, 2020

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 · May 13, 2020

Diggin It said:
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 · May 13, 2020

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 · May 13, 2020

Woodsman603 said:
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 · May 14, 2020

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 · May 14, 2020

Woodsman603 said:
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.