Loader Culvert replacement - How big?

stlbill · Aug 5, 2013

Hello all,

This thread is intended to document the success or failure of the following project:

Replace a shallow 12" x 20' steel culvert that is mostly full of debris with an HDPE equivalent. I estimate the empty steel culvert weighs 200 pounds and the HDPE less than that. For estimating debris weight, a full column 12" x 20' would be less than 16 ft^3. I only need to expose then push/pull the culvert to the side where a scrapper will pick it up.

Cost is the primary constraint. Time is not a constraint, but one weekend is the goal.

In addition to hand tools and physical labor, I plan to introduce a Deere 2305 tractor with 200CX loader and 260 backhoe. The loader has a 61" smooth bucket. The backhoe has a 16" tooth bucket, a ripper/trencher and a static thumb. I also have a 60" 3PT rear blade for final road grading. The loader breakout force is about 1,000 pounds. The backhoe breakout force is about 2,000 pounds.

I'm using this machine because it is what I have at no additional cost. Will rent or hire a larger machine only if necessary.

Photos attached. Opinions welcome.

FTG-05 · Aug 5, 2013

Sorry if this is a dumb question: Wouldn't it be easier and/or cheaper to water jet it out? Maybe no water available???

In any event, good luck!

GPintheMitten · Aug 5, 2013

I think that equipment is up to the task.

Is the culver just full of debris/dirt or is is crushed. From the pics, the culvert appears to be usable. I've cleaned culverts out before. Open up the ditch at each end to get good access, use water and shovels and other tools to loosen the dirt/gravel out of the inside of the culvert. If you could get a power washer in the area, that would help clean the it out.

Of course, that would be more manual labor compared to using the loader and backhoe to rip it out of there, contour the ditch and place a new culvert in there. You might also be able to reuse the current culvert it you remove the gravel from the top and are somewhat gentle with it.

I'll stay posted to see how your project goes.

Edit to add: I see FTG05 was thinking the same thing... he posted as I was typing.

Grandad4 · Aug 5, 2013

Should be a good weekend project. We've done several similar culvert replacements over the years, although we used steel replacements. You'll find the backhoe will help a lot in loosening up the packed gravel. Try to keep the actual gravel separated from any fill material underneath so you can replace it in the same order. Be sure to compact the filled-in material as much as possible, but it will take some time to settle fully. It looks like the ditch on either side needs reshaping so it drains better. That may help keep the new culvert from filling up so badly. Are there any buried phone lines, etc. to worry about?

s219 · Aug 5, 2013

So I assume you will bring in more fill material for the top of the pipe? That's definitely sketchy right now. Should have 9-12" fill over top of an HDPE pipe, and go for 12" to accommodate cement trucks, etc. I agree with the others, if the steel pipe can be jetted out, then don't even mess with pulling it out. Add some material over the top to make a real culvert, and you're good to go. I'd only pull the pipe if it was damaged/rusted beyond repair, or improperly installed.

A 20' 15" HDPE pipe is easy for one man to handle, so it probably weighs 60-70 lbs.

M E Race · Aug 5, 2013

If the HDPF is exposed like the steel one you will slice the top off the first time you grade the road. To bury it deep enough you will have to lower the grade on your ditch, which will def add to your time frame.

Gator6x4 · Aug 5, 2013

If me, I would take the backhoe and clean the ditch out at each end of the culvert. Clean back several feet. I would then take a round nose shovel and see if the silt had closed in more than three or four foot of the culvert.

You may be over engineering, or over thinking. The front end loader in float and used to back drag will spread a lot of materials. Using the loader to spread gravel or dirt will save removing and replacing the backhoe.

If you have to remove the culvert, use the loader and dig down on each side. You may want to use barricades or some other type of traffic diverter on the road side when working. Nothing like looking in the face of a female on a cell phone without a clue others also are using the roadway.

PSDStu · Aug 7, 2013

I'm assming culvert replacement/cleaning isn't something that the County Road department does in your area?

/pine · Aug 7, 2013

Just replaced a culvert and when questioning contractors most all agree the rule of thumb is to use the biggest pipe you can and still have 12" of cover min.

They do make oval (low profile) pipes for for some grade conditions...

luvmexfood · Aug 7, 2013

I agree with /pine. Use as big a culvert as you can. When I installed mine I was not available to meet with the State Highway Department so my father met them for me. Dad grew up in the great depression and was very conservated. Anyway, they recommended a size and he talked them down a size to "save me some money" but didn't tell me at the time. You crossed the culvert and then I had a set of concrete cattle guards to cross. Long story short everytime we had a bad rain storm the culvert could not handle the water and the mud and gravel filed my cattle gurards. Takes about 4 hours to dig them out. Ended up digging out old culvert and replacing with larger one and raising the cattle guards about three feet. No problem since. I would go one size larger on the culvert and maybe the water will flow on thru and not let the sediment build up in it.

Coyote machine · Aug 7, 2013

1/2 size increase to 18'' from 12" increases volume of water able to pass through by 5 times!
AND HDPE flat bottom, (interior) reduces chance of rock/sediment clogging.
Our town is replacing LOTS of clogged/rusted out smaller diameter culverts. Also, with the weather being what it is these days- bigger definitely is better, for now and going forward.

Grandad4 · Aug 7, 2013

Adequate drainage is indeed a concern. But looking at Stbill's pictures, I'm not seeing how to fit in a larger diameter culvert and also add topfill material above it. His smaller culvert is already barely covered underneath his driveway, which appears to be level and on grade with the road, and the ditch looks quite shallow (pictures can be deceiving). Seems to me to make his culvert bigger and also cover it with something like 12" of material, he'd have to either re-dig the entire ditchline along the road a foot or more deeper or he'd need to build an 18-24" whoop-de-doo hump over that culvert. If it were my place, I wouldn't want to do either. Maybe a better answer would be doubling up with a second culvert.

Because of the shallow cover, another steel or even concrete culvert might offer more strength than HDPE. Also, we've found packing the culvert in crusher run , stone dust or similar material seems to help carry traffic loads because it packs so tightly over time.

paulharvey · Aug 8, 2013

If cover is the concern ERCP (eliptical reinforced concrete pipe) is the answer. 12"x18" ERCP would be fine wouldn't it.

stlbill · Oct 1, 2013

Hello all,

Thank you for the abundance of information!

I decided to take FTG-05's advice (a big personal thank you!) and try to clear the culvert. It would save the cost of a new culvert... at least until we get enough rain to verify the pipe can handle all the runoff.

@PSDSTu: This is a private subdivision project and not on a county road.

The 260 backhoe exceeded my expectation on this now tiny effort.

I used the 16" tooth bucket to expose the downstream end of the culvert giving water a place to exit. Then I switched to the smaller Bro-Tek Ripper/Plow bucket and in two quick passes made a ditch downstream of the culvert all the way to the tree line. The ripper/plow earned it's keep for this one task alone because with the 16" bucket I could not dig into the rocky ground using the dipper circuit. It was troublesome enough to switch buckets that a hand shovel proved easier to move the pile at the end of the ditch.

Once the downstream end of the culvert was exposed we used just about anything we could to chip away at hard clay and roots occupying the culvert. Eventually we achieved daylight - a horizon really. The bottom half of the pipe is still clogged about 4 feet in, but we expect rain will quickly erode it (see below - still waiting to know if we are right).

I also spread 2 yards of 1 inch clean gravel where water had washed. I am mad at myself for not matching it better. Now I have to do the whole thing in limestone color. :thumbdown:

It has been about a month and St. Louis is still waiting on enough rain to tell if the pipe is fixed or not.

Here are the photos:

stlbill · Oct 1, 2013

I forgot to add:

When we ever get enough rain to find out of this is fixed, and it turns out not to be fixed, the plan is to power wash the remaining clog and debris. I have a 4200 PSI @ 4 gallon per minute power washer and 275 gallon water tote. The part of that plan not complete - which has kept us from doing it already - is not having clean water at the job site, electric to pump clean water from an on-site 1 acre fishing lake, or a truck and tandem trailer to haul the tote full of water from someone's house.

FTG-05 · Oct 1, 2013

You're welcome! Remember, even a blind squirrel finds a nut every once in a while!

BTW, where do you live? That street sign, does it really, really say "Skinny Hoes Unite!"??? And what kind of person are you that would live on a street named that????

stlbill · Oct 1, 2013

Thanks, I needed a chuckle! Been a busy day at the office! The sign says "Sunny Acres Lake". Hopefully nobody else misreads the sign like you did! This is a fishing lake in a private residential subdivision near St. Louis, Missouri. We have all the normal problems of any property owners group starting with residents who don't pay their property assessment resulting in some overdue repairs. Missouri law leaves little recourse for collection until the property changes hands or the amount owed exceeds a large portion of the lot value. Our new board is trying hard and we are not paid any salary. If you want to know more visit Sunny Acres Estates. Thanks again for your suggestion!

Coyote machine · Oct 1, 2013

stlbill said:
I forgot to add:

When we ever get enough rain to find out of this is fixed, and it turns out not to be fixed, the plan is to power wash the remaining clog and debris. I have a 4200 PSI @ 4 gallon per minute power washer and 275 gallon water tote. The part of that plan not complete - which has kept us from doing it already - is not having clean water at the job site, electric to pump clean water from an on-site 1 acre fishing lake, or a truck and tandem trailer to haul the tote full of water from someone's house.

Do you have a local fire dept that could come out and flush the culvert, for perhaps a donation?
Your stone will mix in eventually. Better to have some of a different color than none of the right color....