Putting in a gravel driveway

[dodge man]

I have seen field tile type pipe installed alongside highways on Illinois. Usually where there is high ground alongside the highway that would force water into and under the highway. I wouldn’t do along side the driveway. If you can drain the water across the driveway that will work, part of mine is that way. This works as long as it’s not concentrated in areas which would cause erosion.

 

[paulsharvey]

The ground does slope from the high end of the driveway to the low end naturally and all the way to the back of the property. That is still the case unless we back fill some of that area which we might. Even backfilled there should still be a slope.

One of my thoughts, that wouldn't involve a culvert is to build up the high side until it is level with the rest of that side of the driveway. Then the entire driveway is level. Then handle water management either by pitching the entire driveway so the water sheets off to the low side. I was also thinking that if I went with a crown I could bury perforated pipe, wrapped in fabric, to both sides and move water that way. I've not seen it done that way before but it was a thought similar to what you would do along the foundation of a home.

I don't like perf pipe, it gets clogged, and had a way of moving when placing material and back filling.

 

[paulsharvey]

I would think that is too low though. If the bottom of that dip is 7' lower than level with the rest of the driveway, and I already have material to either side, I would think I'd need to be at least a couple feet higher wouldn't I to keep the culvert fro being buried? Or maybe you are thinking I need to remove material on both sides to create a path for the water?

See right below, LouNY is 100% right.

I took the liberty of drawing the world's most primitive Plan and Profile sheet. So, assuming we don't want gravity walls/retaining walls; the red lines on the cross section are a mild fill and mild dip, with the plan sheet slope shown in black, as with the pipe show in black on the plan sheet.

If we want to remove the entire dip, see the blue lines on both the plan sheet, as well as the matched profile/cross section.

 

[paulsharvey]

As I hope I showed, by adding the additional fill; we have by default lengthen the needed pipe.

12 ft roadway; 15" pipe, and 12" fill and 12" rock; we need a pipe; we need 38 LF of pipe. (at 4:1)

12 ft roadway; 15" pipe; 24" fill; 12" rock; we need 46 LF of pipe (at 4:1)

If we have 15" pipe; 48" of back fill; and 12" of rock; we have a total rise of 6'3" and that means each end of the pipe needs to account for an additional 25LF of pipe (keeping a 4:1 slope) or 19 LF if using 3:1. For a total length, of 62 LF using 4:1 or a 50 LF if using a 3:1 slope.

 

[paulsharvey]

A 60 LF 15" CMP is going to come as 2 sections, so you also need a coupling band, and I'm guessing band, and 60 LF, we are probably over $2500 for a pipe that long.

 

[paulsharvey]

So, looks like 15" CMP is around $550/20 LF, and coupling bands are at $40/each.

Kinda all boils down to $$$.

 

[paulsharvey]

Now; ill throw another thought; you can always try to retaining wall approach and vertical sides; and add additional backfilled slopes and pipe extensions in the future; but it will be harder to get in there, and likely the outside of your roadway will "sluff" off some; but it's not that expensive to retro fit. It might just work; but I'm betting against it, with a 7 ft fill.

If you truly want to take that approach, consider doing something similar to an MSE wall; mechanically stabalized earth; were in your case, you would have SS cables, or rods, or something that connected both walls, E and W, and went through the embankment, to keep everything from shifting and putting outward pressure on the walls. I dont like this approach, as it's complex, adds cost, and frankly; dirt is cheap, and there is an engineered design to eliminate the need (minor dip at this location).

 

[ning]

Yep. Gave them what I was looking for. This is the full quote:

What I can tell you is if your driveway is 600'Lx12'W and your garage area is 38'Lx55'W and you want 1' Depth of road base (4"minus bank run gravel) you would need 412CY of material.
412cy (4" minus bank run gravel) x $15.00 = $6,180.00
Delivery = 23 loads x $115.00 = $2,645.00
TOTAL = $8,825.00

I assume there's slop in the calculations to account for settling & compaction?

Because (600*12 + 38*55)/27 = 344 cy (estimate is 20% higher still)
and if we go a foot wider on the edges everywhere (just throwing this out there, assuming that you have 12' of good width and then that final foot ends up sloping more) then
(601*14+39*56)/27 = 392 cy (estimate is 5% higher still)

so I'm curious how they do the volume estimate?

 

[paulsharvey]

BTW, everyone has different things that bug them, so, if the dip or vertical curve is going to pass you off every time you use it, by all means, spend the money to remove it. A smooth, rounded, long vertical curve doesn't bother me.

 

[dodge man]

Paulsharvey drawing is exactly what I was talking about when I said a pipe in a low area. I was a land surveyor for a civil engineering firm for over 35 years and our plans looked like that just a little more official with an engineers seal on it.

 

[Too many Kubotas]

The culvert needs to go in at the elevation the low area is. Then if that’s not deep enough build the road up high over it to get your depth of cover.

This is why I have so little above the recently lengthened culvert.

The elevation of the culvert is set by the ditch, and then the sections of driveway on the sides of it are where they are. I did not want a hump over the culvert, for a couple of reasons, snow plowing being one.

That's basically why I filled in the dip at the road end of the driveway. It was quite shallow, but a pain when plowing.

Will this hold up over time? Based on my experience, yes. The most weight it'll be subjected to with any regularity is 40,000 lbs., and with only about 16,000 on the heaviest axle. Other 12" culverts have lived through it, with less than half the dirt on top.

If for some reason it doesn't hold up I'll redo the ditch. I really prefer the whole thing to be as flat as possible. Looks a lot better that way, too.

 

[dodge man]

They make low clearance pipes that are stronger, usually concrete, and they make special shaped pipes, often called squash pipes.

 

[Too many Kubotas]

They make low clearance pipes that are stronger, usually concrete, and they make special shaped pipes, often called squash pipes.

If they're equally affordable and simple to lengthen, I may be interested at some point in the future.

 

[paulsharvey]

So, for humps, there are multiple good, or atleast workable solutions;
1- substandard coverage, could shorten life of the culvert, but can be fine for low traffic environment
2- a swale driveway, typically with a concrete or asphalt surface, allow water to flow, used for a shallow ditch, maybe a drive dips 6% away from the road, then up 6-10% at the back. Can have issues if you dont manage the swale right
3-ditch block drive; the drive has a small maybe 6" down from flush center, water stages up (and mostly soaks in), before flowing across; often not allowed, cause it causes water to sit, doesn't work so well in clay areas
4- Elliptical pipe; so, I think a 15" CMP equivalent is 12"x18"; 18" equivalent is 14x22; it's not a huge savings, but it can help; down side; ERCP is more money, and can be a bit more difficult to install;
5-instead of a single 24" say, maybe dual 18s, or possibly dual 15s; remember we are dealing with volume, so don't think that dual 15s= a single 30";
6- Fords; have a hard bottom surface, either rock, concrete, or engineered material like grates on the bottom, and rive through the water; pretty much not used in modern world, but it still works; got to have a water gauge visible, so you can clearly see your driving through 12" of water, not 36"

 

[paulsharvey]

If they're equally affordable and simple to lengthen, I may be interested at some point in the future.

Couple types; most common is ERCP; Elliptical reinforced concrete pipe. One catch; generally speaking, anyone's 18" RCP will home up fine with other manufacturers; ERCP, not so much. You can always do a "dissimilar pipe collar" which is butted up, wrapped in fabric, and a concrete band poured connecting both pipes, 360 degrees around, and over lapping both pipes.

Pipe Arc, has a flat bottom, and an arc on top, equal volume in a lower rise; never actually seen this installed; it kinda mimics old brick arc storm drains.

 

[paulsharvey]

As for equally affordable...

to the best of my knowledge, there is no poly or corrugated metal Elliptical pipe widely available, so, maybe we are talking 50% more per foot over RCP; but we are probably 2x or maybe 3x the cost of CMP or poly pipe for equivalent ERCP

 

[paulsharvey]

So, sample section of 1; $40/lf for 18" RCP vs $48/LF for 14x23 ERCP.

Also, note, this manufacters 18" equivalent is 14x23; some others are 14x22; that's what I meant about it being harder to mix/match

 

[Too many Kubotas]

Pipe Arc, has a flat bottom, and an arc on top, equal volume in a lower rise; never actually seen this installed; it kinda mimics old brick arc storm drains.

That would make me want to try cutting a 24" culvert in half.

Okay, it would surely sink in to some extent, so maybe starting with a 36". Or weld in some supports on the bottom to help keep the edges from sinking in.

 

[paulsharvey]

I found a manufacter of corrugated metal pipe arch in Penn. No idea on prices, and I have personally never seen this used down here

 

[paulsharvey]

That would make me want to try cutting a 24" culvert in half.

Okay, it would surely sink in to some extent, so maybe starting with a 36". Or weld in some supports on the bottom to help keep the edges from sinking in.

Those old brick arc systems used a flat mortared or poured brick floor, and then a self supporting arc "roof". I wouldn't do it without a "floor"