Culvert Pipe Quandry

[Claire Knowles]

Making a very long story short, I own a private road with a 24" round polymer coated culvert pipe underneath it; the pipe is 24 feet long, and is only covered with a foot of dirt roadway. My question is...how much weight can that pipe withstand before it gives? Loaded dump trucks? Loaded tractor trailers? I am worried that the pipe will give in because of all the weight going across it, and I'll be stuck paying the bill to install a new one. I've looked this all up on-line, but since I don't have a clue about algebra, I can't figure out the ratio. Can anybody give me at least a close guess as to the weight capacity of the pipe?

 

[GolfAddict]

For what it's worth, what I've heard is that you should have 50% of the diameter of the culvert. So, having 1 foot of road above your 24 inch culvert is plenty to hold up to most any traffic.

Again, that's just the rule of thumb I've heard. Hopefully those more knowledgable will chime in.

 

[RDrancher]

If you're referring to HDPE corrugated polymer pipe, a 24" pipe requires 12" minimum cover if it's going to be used under asphalt pavement, 12" minimum including pavement thickness for concrete, or 18" minimum if the surface material is dirt or gravel. Strength depends on proper pipe bedding and compaction (starting with the bedding below the pipe.) It depends on what type of material was used too. Will your pipe support repeated loads from dump trucks or semi's?...maybe. If the pipe will be seeing these loads only during construction, I'd place a couple feet of temporary compacted fill above what you already have during construction and then cut it to grade after.

 

[s219]

You should be fine. With enough cover that is properly bedded and compacted, the pipe only sees hoop stresses (like an arch). It doesn't really carry the direct load.

I have a 15" plastic culvert pipe with about 12" fill over the top, which I installed myself (there's a thread on here with photos). We've had concrete trucks and the like come through with zero problems.

The 50% rule of thumb is a good one to use. Some states have additional guidelines depending on the pipe's material and type of fill or road cover. I followed my state (VDOT) specs, since the culvert had to be approved by the county road department. You should be able to lookup culvert specs for your state.

If in doubt, you can increase the load capacity of the crossing by adding more cover over the top of the pipe.

 

[Briana03]

Welcome to TractorByNet!

We moved your thread to the Related Topics forum.

 

[vtsnowedin]

A 24 inch polymer coated pipe? What is coated ? steel? Aluminum? What kind of "polymer" and how thick is the coating and how thick ( ie. what gauge is is the material that is coated) ? Anything new should have some printing some where that gives an ASTM or AASHTO spec that it meets. Google that and you can find what loads it can take and what cover and backfill you need to make it work.

 

[Claire Knowles]

Thanks so much for your input on my pipe problem...guess I should have been more specific on the pipe. It's corrugated steel with a polymer covering, and was put in with no bedding under it, just in a dug out ditch. It was covered with fill dirt, then smoothed out. I would venture to guess the dirt is now compacted from the traffic that travels our dirt road. The pipe sticks out from under the road 8" on one side and about 18" on the other side. My problem is that there is a lot of acreage behind us, and there is talk of building a small development, which the only access to is through our privately owned road. I just don't know if the shabbily installed pipe will handle the literal tons of traffic and materials without causing the pipe to collapse. Thanks so much for any insight you can give me.

 

[vtsnowedin]

A steel culvert will be fine as installed if you gravel the road above it another eight to twelve inches. The extra cover spreads the loads of the truck tires to the earth on either side of the trench reducing the load on the pipe. You should be able to keep sixteen feet wide of travel way over the pipe with the shoulders sloping down three H to one V each side. A few well placed field stones placed beside and over the culvert ends will help hold the fill from washing down into the ditch. A good job for a tractor and loader.

 

[dmccarty]

Thanks so much for your input on my pipe problem...guess I should have been more specific on the pipe. It's corrugated steel with a polymer covering, and was put in with no bedding under it, just in a dug out ditch. It was covered with fill dirt, then smoothed out. I would venture to guess the dirt is now compacted from the traffic that travels our dirt road. The pipe sticks out from under the road 8" on one side and about 18" on the other side. My problem is that there is a lot of acreage behind us, and there is talk of building a small development, which the only access to is through our privately owned road. I just don't know if the shabbily installed pipe will handle the literal tons of traffic and materials without causing the pipe to collapse. Thanks so much for any insight you can give me.

I have plastic pipe under our driveway that I was given for free. I think it is 15-18 inches and I have a foot or two of ABC gravel over it. I put the pipe down on grade and build the driveway over the culvert. The culvert held up just fine to all of the construction traffic at the house including cement trucks.

I would hope that the development that needs access will also be paying for any damages done on the easement that provides them access. Or paying to improve access. What does the deed say about the easement and who is responsible for maintenance?

Later,
Dan

 

[dave1949]

Yes Claire, as Dan said the road care shouldn't fall on you if more people begin using it.

Assuming it is a legal private road intended to serve you and whatever gets built beyond you, there should be a formal arrangement for who pays what percentage of the upkeep. We have Road Associations here in Maine which have strong state law backing--including being able to put a lien on a property for non-payment of their share of road costs.

The private road I used to live on set the cost shares proportional to the amount of road used. The properties furthest from the town road paid the most. That is logical because they are the ones using the road the most.