Driveway Crowning and Ditches

[Anonymous Poster]

I started to cut another section of our driveway last weekend. The past attachment link shows the section cut for the construction equipment, not the new section. The section shown in the attachment will have to be redone after the house construction has been completed. I plan on laying a sub base using 3" diameter rocks 3" deep, followed by 4 to 5" of 3/4" rocks. The total length of the driveway is approximately 1000' long and 16 to 20' wide. The state wants 20' width at the driveway entrance and I plan to narrow it down to 16' for the remainder. It will connect to the driveway shown in the attachment. Do you cut the crown in the earth or is the gravel contoured to a crown? I guess that both the earth and the gravel can be crowned. Also, what shape, width and depth are the drainage ditches? The driveway is not very steep and we did not notice any deep washouts before starting. Any advice would be greatly appreciated. More pictures will follow. Driveway Shot

 

[Anonymous Poster]

building roads for the town highway, we always pulled all rocks possible, (frost heaving) big problem in New England, then center crowned the gravel after 3/4 stone base was laid down. we tapered to a five foot space then dug swaled ditches. Of course when the town owns a twist wrist on their backhoe, makes it much easier, quicker and better looking. Before the twist wrist attachment, I literally would "cock' the machine with stiff legs and dig accordingly. This manuever was a pain and not always safe either..

 

[Ranger]

Can you show us a picture of a "twist wrist" on a backhoe?

 

[Cdash]

It depends if your cutting down. If you were building the driveway up, I'd say crown the earth. This would promote drainage for any water that gets into and through the gravel. It could run out the sides between layers. If your cutting in, it doesn't matter since you have a bathtub no matter what you do.

 

[Darren]

I'd use crush and run #57 which includes the fines. Some call it dirty. The fines bind the stone together. With the low slope you shouldn't get a marble effect as stones roll under the wheels. On a steeper slope the combination you're considering would be a problem.

 

[djradz]

Unless your earth is not suitable for a base, I'd just leave it alone and not cut any ditches. You're building the road up quite a bit so the last thing you need to do is make a place for water to collect right next to the road. The main idea is to get the water not only off the road but away from the road. Like others have suggested, I'd use unwashed crushed with the fines still in. It makes a wonderful surface and stays put. My vote goes for typical county road mix topped off with crushed 3/4" to 1" including fines, raked to a smooth slightly crowned finish.

 

[Anonymous Poster]

sure, the exact one I used can be seen at

www.helac.com/construction/applications.asp#construction3

 

[Anonymous Poster]

Thanks Guys. I spoke to our builder yesterday and he finally mentioned how they put in a driveway. He has been disappointed that we are doing the driveway ourselves instead of paying him $8.00 per linear foot. This was our motivation to purchase a tractor. Anyways, this is what he said. First, remove the top soil down to the clay and crown the earth if possible. Put down a sub base of 3 to 4" of medium sized shale. Finally, put down 5 to 6" of #57 crusher run stone and crown. He said that shale is a good cheap base and the crusher run binds together under pressure. He also mentioned that on a residential driveway with some slope, drainage ditches are not necessary. His information matches what you all have said. Thanks.

 

[dmccarty]

R2,

I built over the summer a 500-600 foot long driveway running
over a culvert. I used a geotextile fabric and ABC. My
ground is either clay or clay growing rocks. I have a pretty
good slope on the driveway, which is kinda a long S, so I don't
seem to have a problem with water ON the driveway. I did
NOT dig down and fill up with material. Since my soil is all
clay, cutting in the drive would just make a clay ditch to hold
water. I cleared the driveway as best I could. It was tough
in the woods because of all of the roots but I did a fair job.
Before I built the drive I had the power brought in and waited
3-6 months for the trench to settle.

I put down the fabric and had the dump trucks drop their
load so I could spread it with the tractor. Worked fine unless
I managed to touch the fabric with the FEL or box blade.

ABC is a mixture of fine dust and rocks up to something like
1.5 inches. The fines lock the rocks into strong bond. The
only compaction I did was the tractor and dump trucks running
over the drive. One of the BIG PITAs was if I touched the
fabric I would have to get out a shovel and dig to fix things
up.

The problem was that the ABC had already locked in tight
even though no rain had fallen and the compaction was limited
to my tractor and the dump trucks.

Its been six months or so since I have laid down the drive and
its holding up fine. I don't have a house out there so it is
not traveled heavily but I don't have any signs of wear from
my cars and tractor. The drive has settled quite a bit from
all the rain and I can see the depression from the power line.
Once the house is built I'll dump a few more loads and
smooth things out again.

I think on the flat areas of the drive I only have 4-6 inches of
ABC. The dump trucks running around 55,000 pounds did not
disturb the ABC at all.

I'm a firm believer in the fabric...

Later,
Dan