So, Im looking at putting some more borough road here in Alaska, road building is probably a bit different then done else where. Here we grub up all the organics Dig giant holes bring all the gravel to the surface, bury the organics and spread the gravel, so you have a gravel on gravel base. Anyway, the materiel can get a bit course. Typically, we will pick rocks....forever, sheeps foot, then compact to get our required 6" of 3" minus topping.. I was just throwing this out there to see if anyone has any awesome ideas for removing cobbles that I've been missing out on?!?!
How about a rock rake adapted to your excavator. Rake the surface as you spread it, and cast the rocks off, or pile them to haul away, or whatever you do with them.
Maybe a skeleton bucket? Actually a screening bucket would probably work better. Something like this. http://www.youtube.com/watch?v=oR0jmV9oTtg
My understanding of grading shot rock like you have pictured is as follows. You always try to start on a surface that is done. You dump your truck a good distance from the face of your fill. Now as the dozer pushes that pile, you are more of less screening your big rocks out. Those big rocks go over the face of your fill. You continue pushing your pile, and as you go your bigger rocks are collected up. This leaves mostly fines on top for you to finish out with.
Have you tried walking it in with a dozer? Thats how we handle our shale here in pa, but its a sedimentary, and yours might be granite. My initial solution would be to run a screener or screening bucket to make enough fines for the top coat. Other possible options are a degleman rock rake, may have to adjust the width of the teeth to get sizes right. They are basically a 10' wide h.d. harley rake. Another possibility is switching your roller from a sheepsfoot to a smooth drum or a z-bar vibratory. The feet on the sheps fott might be bringing rock to the top & contributing to your problems.
That's the way I have always done shot rock fills. Keep rolling the bigger rocks to the face of the fill and work your fines as cover. The geotechs would always let us go with a deeper fill when working with shot rock, which makes this process a little easier. Alaska, could you not use the shot rock up to -6" grade and then get screened material that meets spec for the topping? Also what is your average fill depth for the course gravel and how thick a lift do they allow you to do?
CM1995 Originally Posted by Turbo21835 My understanding of grading shot rock like you have pictured is as follows. You always try to start on a surface that is done. You dump your truck a good distance from the face of your fill. Now as the dozer pushes that pile, you are more of less screening your big rocks out. Those big rocks go over the face of your fill. You continue pushing your pile, and as you go your bigger rocks are collected up. This leaves mostly fines on top for you to finish out with. That's the way I have always done shot rock fills. Keep rolling the bigger rocks to the face of the fill and work your fines as cover. The geotechs would always let us go with a deeper fill when working with shot rock, which makes this process a little easier. Alaska, could you not use the shot rock up to -6" grade and then get screened material that meets spec for the topping? Also what is your average fill depth for the course gravel and how thick a lift do they allow you to do? The piles are too close together, you will just push into another one and so one. Screened materiel is $$$ 15.5 per yard delivered ($8 at pit) for 3" -. Fill depth is about 15" with required 6" of 3" minus topping. stumpjumper83 Have you tried walking it in with a dozer? Thats how we handle our shale here in pa, but its a sedimentary, and yours might be granite. My initial solution would be to run a screener or screening bucket to make enough fines for the top coat. Other possible options are a degleman rock rake, may have to adjust the width of the teeth to get sizes right. They are basically a 10' wide h.d. harley rake. Another possibility is switching your roller from a sheepsfoot to a smooth drum or a z-bar vibratory. The feet on the sheps fott might be bringing rock to the top & contributing to your problems. Screening bucket or rock rake sound like something I will be looking into. We sheepsfoot to drive the big ones down and then smooth roll. Maybe a skeleton bucket? Actually a screening bucket would probably work better. Something like this. http://www.youtube.com/watch?v=oR0jmV9oTtg This looks awesome! wish I had the $ to get one.
Interesting method and thread, is gravel always present like that ? I have seen simple portable screens made from heavy pipe spaced @ the max dia. of desired material, sharply angled so the large falls off and the fines fall through, probably slow you down to much but it would screen as you pile. Pick it up and move to the next pile, if it plugs up reach out and shake it with the hoe. I'll try to find a pic.
Alaska Now that some ideas are out there, what equipment do you have to work with? That may help with the suggestions. I have some ideas, but without knowing what you have to work with, I may be headed down a dead end.
Needs to be heavy duty, a guy could fab to your specs easy enough
these are excellent pieces of equipment http://www.youtube.com/watch?v=X-iDRAMmTZg&feature=related http://www.youtube.com/watch?v=h2RrkskdJug&feature=related One of these.....................
^^^^^ thats what I would use. You can find them at auction or used for a pretty good price. We almost bought one for a job to screen the dill on a trenching job. Leave the finner material behind and load the larger stuff in a truck.
if your interested in one let me know. There is a used bucket guy around here that has a few for sale. Shipping might be pricey but they might be cheap enough to make it worth it.
The secret is having the muck out of the way, and then dozing as the loads show up. I have family in the Ketchikan area. They build a lot of logging roads, using the method I have mentioned. The only difference is they use a williamson? grid style smooth drum roller. Basically a Z bar pattern on a smooth drum roller, and that tends to crush the sharp edges off the larger rock.
The way I understand Alaska, the gravel piles we see in the picture are dug up right there, not hauled in. It sounds to me like he strips topsoil, then digs a hole to the gravel and piles it where he just stripped, then uses the hole he just dug to bury the next bit of topsoil that gets stripped. Sort of a trade, some topsoil for some rock. What that tells me is that there is no place to push the pile to untill the next piece is stripped. The grizzly, as we call the screen posted by DPete, could be used with a loader. Let he big stuff roll forward, and clean out the fines from the back, carrying them back just a bit to spread as the top coat. That would leave the rock on the bottom, and cover it with the screened material. It may even work if you don't have a loader, just rake the big stuff forward with the excavator, and leave the pile of fines behind to spread on top later. It would slow the initial excavation down some, but be balanced out by less raking and picking later.
Would one of these ever pay for itself? http://www.youtube.com/watch?v=TjxU_lcBNBw
A local contractor has one here uses it on horse gallops etc, He charges over €350 per acre....................the tungsten hammers for it are a ferocious price.................
Thank you very much for the suggestions, I think I will be going for the skeleton bucket if I do get the bid. Seems the most economical, for now.