Culvert Project

[Bird]

Wow! Harv, neat job, but you've got a lot more energy and stamina that I do. I know where there are several culverts that have the ends shored up like Scruffy said; just stack bags of ready mix, but never anyone who filled sandbags like that. And lifting the front wheels to put weight on the bucket to back drag that way is the only time I wish I could use brake steering.

Bird

 

[ejb]

Harv, I have really enjoyed your posts and pics of your project...quick question. Ballpark, how much does each piece of that culvert cost you? What are the dimensions that you are using?

 

[Harv]

ejb -

I had very little choice as to where I bought my pipe, so I'm not sure I want to know if the prices were any good. /w3tcompact/icons/crazy.gif

I bought three 12-inchers at $6.47/ft = $64.70 per 10 foot section and two 18-inchers at $9.48/ft = $94.80 per 10 foot section.

The metal pipes were available in 10 or 20-foot sections and the plastic was available in 20-foot sections only (although plastic is easy to cut yourself). I don't remember the numbers, but plastic was more expensive, at least from this dealer.

 

[Harv]

It was actually a very busy weekend. After culvert #1 was usable, I moved right on to culvert #2. /w3tcompact/icons/tongue.gif

This one required very little digging 'cuz there's a natural channel right where I want the culvert. It did take some hand-digging and the removal of some 12 to 18-inch boulders, but that's why we have big heavy pry bars, ain't it?

This one is quite a bit bigger than the first, but I wanted to keep it fairly shallow so's I wouldn't have to test my tiltmeter every time I drove over the finished culvert. That meant going with 2 side-by-side pipes instead of one larger one. Note -- for proper backfill support, I had to leave a gap between them so I could get in there and do my tamping act.

Did some rock work on the face of this one in addition to the sand/concrete bags. Time finally ran out just as I got to covering the pipes, so I just dumped a few buckets of fill on top and left it there for next time (which looks like it will be tomorrow - Wednesday).

Looking straight across the culvert you can see where I'm going to have to do that trail-blazing I've been talking about. I have mixed feelings about that chore.

One observation about tractorin' in general -- for all the cool things you can do with these machines, I'm most grateful for their function as the world's greatest wheelbarrows. /w3tcompact/icons/smile.gif

For you download gluttons, there's more picts of this project in the scrapbook.

 

[dmccarty]

FYI, I just priced plasic culverts today by phone.

12 inch by 20 feet double wall pipe was 85.95 at one supplier and 100 at another place. Single was was 72.95 at the cheaper place and did not have the smooth inside wall.

This is in the Triangle of NC.

Hope this helps....
Dan McCarty

 

[glennmac]

I am also in the middle of a culvert project to bridge my creek.

I bought plastic pipe. It only comes in 20' sections. My 24" diameter cost $251. 30" is $400. 10" is $67. 8" is $44. I didnt price any other sizes. Of course, I'm buying in Fairfield County, Connecticut, the weathiest county in the country. I hope its cheaper elsewhere.

I am laying two 10' sections squashed side-by-side to each other in a creek bed that is about 40" deep, and has water flowing in it. EEK, this plastic pipe FLOATS, providing new and exciting installation challenges. I am going to be ordering a processed limestone fill with 3/4 inch gravel in it, based on what I read here in the "Colvert?" thread. Costs $10 per ton plus a $60 delivery charge. I don't have a clue how much I need, but I bet I spend more on shipping than on material. Plan on putting some top soil on top like Harv.

I bought a tamper and a 72" pry bar today. Figure I can use the bar to rod the fill and to pry boulders. Since the side-by-side culverts are already squished together and against the relatively vertical walls of the creek, it is going to be difficult to rod fill between the two pipes and between the pipe and the creek walls, especially with the water flowing and trying to wash everything away. Am thinking of using sand bags or concrete bags somehow.

Glenn

 

[glennmac]

Harv, re those bucket forks in your pictures: Do you like them? Have you tried them to lift and carry brush? How long to get on and off? Where did you get them? How much? Did you ever locate the bucket rake that Del had pictures of?

Thanks, Glenn

 

[Harv]

Glenn -

Sounds like you're on your way to some experiences I can relate to. From what you've said, though, I feel compelled to share some tidbits I've learned from my own research (anybody with actual experience, feel free to intervene).

You're certainly right about plastic pipe floating, and from what I've read, that's a big problem especially with the larger pipe (greater than 12 inches). Big loud caution here -- it's notjust an installation problem! Once the pipe is buried and the creek level rises with the rains, the buoyancy factor is tremendous and it can burst right up through your roadway. /w3tcompact/icons/shocked.gif

Somewhere I saw mention of using proper "anchors" on HDPE pipe where floatation could occur, but I never saw a picture or description of what they were talking about. Might be worth a phone call or two.

Also, with plastic orsteel the pipe strength is derived from proper backfill. Only reinforced concrete pipe can support vehicle-sized loads with only "casual" backfill. The rule of thumb is to have at least one pipe diameter of fill on either side of the pipe (I'm cutting it a little close on that score myself). If your pipe is butted up against a "normal" soil or clay, it may eventually deform. Boulders and rocks should be kept away from the pipe, since they will cause localized pressures and cause detents into the pipe, degrading your water flow.

I didn't find any specific information on laying side-by-side pipes, but again, the strength of the pipe is a factor of how well it is supported, particularly below the centerline. That's why the backfill material must be evenly compressed in layers by tamping. I'm concerned that if your pipes are "squished" together (I love technical jargon), they will not have proper support in the most crucial area.

As for the fill itself, I think it was right here on this board in one of the culvert/colvert threads that I learned about the crushed limestone. It seems to have different names depending on who you're talking to, but the important thing is to make sure it contains plenty of fines (sand) in the mix. That's what allows it to compact so firmly. I can tell you that as I tamped it down I could see and feel it compacting down to a very solid material. I placed layers of about two inches and tamped each one down to little more than one inch, at which point it started to feel like I was walking on concrete. Amazing stuff.

One of the early posts on this subject referred to a page with a diagram that I used as part of my guidline (see attachment).

The last factor for a successful culvert, from what I've heard local experts say around here, is the "overflow". That is to say that you must assume that sooner or later the creek flow will be more than your culvert can handle. The secret then lies in providing a non-destructive path for that water to take. I haven't completely dealt with this part yet, but my plan is to provide something like a swale at just the right level, leading off from the upstream end of the culvert. Here's a sketch of what I had in mind.

To tell the truth, folks, I'm sure my culverts will be okay 99% of the time, but I'm worried they aren't going to survive the inevitable torrential rains that come once or twice each year. Any words of wisdom for me and Glenn?

 

[scruffy]

Harv, with or without your swale, there will come a time (as you've mentioned) when the capability of the culvert will not meet the demands placed upon it. In constructing your swale you have the choice of constructing out of natural materials or use your crushed lime mixed with sand and concrete to make a more solid base for the overflow. The whole point is to avoid the washout that may occur, without overkill and cost. The one thing I learned in North Western California, and Southwestern Oregon, is to initially place an adequate culvert and ditching in the first time around. Plan on your large storm runoff, and don't worry to greatly about the storm of the decade or a 100 year storm. Those get too expensive to prepare for, particularly on the type of road you are constructing.

 

[Harv]

Glenn -

About the bucket forks --

<font color=blue>Do you like them?</font color=blue>

I love them to pieces. /w3tcompact/icons/laugh.gif Handiest bang for the buck so far.

<font color=blue> Have you tried them to lift and carry brush?</font color=blue>

A little, and they worked great. I'll be doing a lot more of that pretty soon.

<font color=blue>How long to get on and off?</font color=blue>

Less than a minute for both forks. (See attachment)

<font color=blue>Where did you get them? </font color=blue>

I just told my tractor broker ('Miracle Mike') I wanted them and they arrived with the tractor. They're Gearmore forks, so they should be pretty easy to come by.

<font color=blue>How much? </font color=blue>

I paid $350 through Miracle Mike. Brand new.

I got the smallest of the four available sizes. They weigh 90 lbs. apiece (one reason for getting the small ones), but the built-in handles make them quite easy to handle. They are 2 x 3 x 32 inches and have a lift capacity of 1,000 pounds (more than my loader).

I did connect with the bucket rake manufacturer, as I mentioned in a previous post, but when neither Miracle Mike nor 2 tractor dealers I talked to had never seen or heard of them, I got cold feet. The $600 price tag didn't help any, either.

Fact is, I really I wish I had the bucket rake for my trail blazing adventure the next couple of days, but I'm gonna just get familiar with what I do have and keep the rake in the back of my mind.

Feel free to get one and let me know what you think. /w3tcompact/icons/wink.gif

 

[glennmac]

Harv-

Thanks for the info. I knew you would have done a lot of research. My culvert situation is different from yours, and certainly falls into the category of an experiment.

First, I have creek that flows all year. It meanders through my soft, flat wetland area. There is a defined channel about 40-45" deep with relatively steep bank walls.
There is about 3" of water in the one straight area where I am dropping the two 24" pipes.

This is an exercise in compromises. There is no way I can install a pipe that won't overflow during flood, simply because in flood the creek will overflow the banks and spread over the flat surrounding land. The only structure that could avoid overflow would be an arched bridge, but I have rejected that for cost reasons.

That leaves me with trying to use as much pipe diameter I can to contain high flows, consistent with the overfill requirements. The literature on the ADS plastic pipe says that with 12" of cover the pipe can handle "H-20 loads" and with 24" of cover it can handle "E-80" loads. Problem is, I can't track down what those things mean. But 12" seems to be an often repeated number, so that's the minimum I want. If I put a really high volume pipe, like 48" diameter, it will stick up higher than the banks. Even a 36" inside diameter pipe will mound up higher than the banks, and still won't contain flood flows. So, I opted for 2 24" pipes side-by-side. That gives me almost as much flow diameter as a 36" pipe, but allows me to put at least 15" of fill on top before I reach the bank height.

I will be able to get some gravel on the sides of the pipes, but they will basically be butting into each other in the middle and into the soft banks on the sides. I dont know how I am going to get gravel under the center point where the 2 pipes touch or under the "haunches" at the sides. I may try to lay sand bags in these places and try to rod gravel down into them. But the water will be trying to wash things away.

Geez, bursting upward through the surface! These 10' long pipes are definitely floating on the 3" of water now. There certainly will be a lot of upward buoyancy when the creek is full. My only hope is that the several tons of fill on top will be more than enough to counteract that. I know that one ton would sink a ten foot canoe, which should have more flotation the pipe.

Well, as I say, we'll see. The only thing going over this is the tractor, and I can easily tear it all out if it doesnt work.

Glenn

 

[Harv]

Glenn -

Hope I didn't come on like a know-it-all. /w3tcompact/icons/blush.gif

Truth be told, I think we're both in the same boat (bad analogy?). I've accumulated a lot of information, but I haven't adhered to hardly any of the rules myself. I'm in experimental mode, too.

My channels are quite shallow and they overflow their banks during heavy runoff. Deep down I think at least some of what I'm trying to do is futile, but since my goal is to have tractor access to as much of the property as I can for as much of the year as possible, I had to give it a try.

We should be making some interesting posts to this thread in a couple of months, no? /w3tcompact/icons/crazy.gif

 

[Harv]

Scruffy, Bird -

I almost forgot about your comments about the ready-mix concrete sacks. I have a way of over-thinking things like this, so this is how my "logic" went --

Since "proper" culvert backfill is supposed to slope upward from the bottom ends of the pipe at about a 45 degree angle, and I decided I couldn't afford to give up that much road width, I decided to shore up both ends as sort of retaining walls which would allow me to build up steeper.

My brilliant idea of using ready-mix was motivated by wanting to make these retaining walls as sturdy as I could without actually building forms and running rebar. As I looked at some of the recent retaining walls in my own suburban neighborhood I saw that they were all built with concrete blocks made just for that purpose. A lot of different colors and shapes, but the one common feature they shared was a "lip" on the bottom backside of each block which prevented it from being pushed forward relative to the block below it.

I actually did consider laying the paper sacks as they came from the store right on top of each other. But I didn't see anything about that structure that would offer much resistance to one-sided pressure, other than their sheer weight. By transferring the material to sand bags and not filling them too tightly, I wound up with building blocks that were easily conformed to the contours of the ground and the pipe and to each other. I tried to arrange them on top of each other in such a way that once they became rigid, their shape would prevent them from being pushed off of the bag below.

Overkill? Probably. In fact, I hope so. /w3tcompact/icons/smile.gif

 

[Rowski]

Harv, Glenn,

One thing to keep in mind it during heavy run off you need to make sure the culvert(s) don't get restricted or plug up!

Derek

 

[glennmac]

Harv-

Your culvert project pictures came at a very propitious time, as I have spent the last 4 days running around getting info and preparing to begin my culvert project. In fact, you raised an issue that I had never thought of and which is now terrifying me: whether I can use all 10' of my culvert or whether I will have to slope up the ends. I did the same arithmetic you did: 5' tractor, so 10' foot section of culvert should be enough. I am now kicking myself, since it now seems obvious that I can't get the fill right to the edge.

Right after your pictures I went to the hardware store to ask about the concrete trick of letting it harden in the bag under water. No one knew if it would work. They were nice enough to call the sacrete manufacturer, who said a bag would harden under water. Another guy cautioned me that inside the paper bag might be a plastic bag, and if that is so, the water won't penetrate the bag unless I re-bag it all in paper. Problems, problems, problems. I'm now going to experiment with your concept of laying sand bags along the top edge of the culverts.

If I hadn't already cut the 20' section of pipe in half, I probably would have spent more money to have a 20' crossing, but that of course would have required hand digging out a 20'+ section of the meandering creek.

I am taking pictures with my APS camera but will be unable to post in real time like you digital photo owners.

Glenn

 

[Harv]

Glenn -

I'm not sure you need to be terrified about the 10-foot pipe issue. Since I started my own project I've been looking more closely at other culverts as I come across them. Despite the "rule" about sloping up from the ends, it seems to be fairly common practice to do exactly what we're doing. In fact, on my last trip up to the property I drove by a culvert that had the vertical stack of sacks (couldn't tell what was in them) at either end. It appears to have been there for a number of years and it still looks great. Now, it did have a full 12" of coverage topped with asphalt, so that may be a factor, but judging from that and how solid my first culvert feels already, I'm somewhat encouraged.

Thanks for confirming that the concrete will harden under water. I thought I had heard that before, but I never really checked into it. /w3tcompact/icons/blush.gif

As for the bags themselves, I can tell you the "Quikrete" brand comes in all-paper bags. If you decide to go with sandbags anyway, both the burlap and the plastic kind are quite permeable to water. I'm using the plastic (35 cents each @ Orchard Supply) mostly 'cuz that's the best price I could find.

You've clearly got a good head on your shoulders, so I have a hunch you'll get the job done well. I'm looking forward to seeing your pictures.

I'm out the door again to re-visit my own project, so I'll post another update probably on Friday.

 

[scruffy]

Harv, and all, the concrete bags with the plastic liners are easily 'cured' of their propensity to keep water out. Take a piece of 1x4 and drive a few nails through one end, and as you put it in place, perforate the bag several times with a few blows (don't break the bag though!). This will allow the water to soak into the bag. I've used this method several times over the years, but with my preferred method of pushing the nail board in with my foot, rather than wacking (I broke a bag or two).

 

[Anonymous Poster]

Harv,

I've been following this with great interest, as I too have been considering installing a culvert over a stream in my woods. I think you're doing great. But your overflow sketch looks like the *bad* example from the Landowner's Guide to Building Forest Access Roads.

 

[glennmac]

Scruffy, thanks for the stabbing tip. Maybe I'll just use one of our el cheapo 25 year old steak knives that were never sharp to begin with. Nothing, not even concrete, could make them duller.

Three days of golldang rain again. My creek is rising and those two pipes are floating around. I have ropes through them but I can't lift them over the bank with my aging body. I maybe could FEL lift them out, but of course Kubota expressly forbids that practice.

Worse, the creek area is going back to terminal muddiness, and the gravel delivery guy will I am sure refuse to come down the hill to my creek area in these conditions. This means I will have to let him dump in an inconvenient remote area for me, or wait for drier weather and lose at least another weekend.

I am positive that weather used to be normal when I was a kid.

Glenn

 

[glennmac]

Dave-

I am confused by that drawing. I can't tell what it is trying to illustrate and what is the "bad" from the "good" in it.

My approach the the flooding issue is simplistic: c'est la vie; che sera sera; what will be will be (for you Doris Day fans). My creek is in a very flat area and is not flowing fast. Overflow will result in a gradual spread in all directions sort of evenly, not a torrent in any particular direction. So, I am not going to try to constuct an overflow channel. I think that might make things worse. Of course, if the creek were an intermittent one, tumbling with great force down a steep hill, I might have a different view.

Glenn