At the two pits I work at we are frequently near (with a foot) the water table. There has been occasion that we are stuck working through this quagmire and it will sometimes be necessary to drive through and make mud, but one time it was too much so we started throwing everything we could into it up to 5 inch rock. All of this just sank so does anyone know a good way to build up a sink hole for a loaded 950 or 966 size loader to get through? I also found one the other day, no water came up but as soon as I started filling the bucket and lifting the wheels just dropped a good foot!
I was working a bank just above the clay and water table a few months ago and ran into many of the same problems you discribe. I ran into only one sink hole. There was wet clay in it and it was about 10 yards in diameter. I dug as much of the wet clay out of the hole as possible and filled it with the cleanest material I could find. As for the digging out of the bank I kept spreading as much stone and clean material in front of the bank as I could and blading it down. Other than what I mentioned, This kind of work enviorment will help a loader operator develope a " throttel foot " rather quickly. I hope this helps.
In a way it does, but at the same time it doesn't. I will be glad when we close that damn pit down!
rip rap always works
What the heck is rip rap anyways? We have it at our quarry but I've never seen the stuff.
rip rap Rip rap is 6-8"or bigger rock. As far as getting rid of softspots... Komatsukid has the right idea. Dig as much of the slop and soft stuff out and put dry clean and bony material in to try and bridge anything you don't get out. It's not the fastest way, but it works.
Excavate the soft material, place geo textile down first, and then rock over that, it will make all the difference.
That works great for parking lots and roads, but this situation is the bottom of a gravel pit. It may be hard enough convincing the powers that be to dump stone in the wet spot, as its just throwing sellable product away. I couldnt imagine asking for fabric too. Ive had a similar situation in the demo business. Except it portions of the slab where the concrete had failed due to soft subgrade. I let the area rut up, skim the material off, then rut it up again. Then i would dump crushed concrete on that area, rut it up again, add more concrete. It seemed that dumping in the ruts helped mix the stone in with the bad subgrade. Then the additional layer of stone helped set everything up. If the area was still soft I would bridge the area off with more stone, anywhere from 6 inches to a foot above the soft area
I have been having the same problem on my jobsite lately. We are running sewer and water through an industrial park that 2 weeks ago was literally a swamp. Our earthworks division excavated the topsoil and muck away, filled with about 9ft of good clay and now I am digging through it. Only problem is the ground is unstable as all hell. our 385 is sinking in almost 3ft when digging, our 330 can hardly move half the time, and our volvo wheel loader just makes massive ruts. What I have been doing is blading up dry from across the jobsite, excavating some of my wet out, mixing it up, and then let it heal for a couple hours while the sun beats down on it. I have been raking it with my teeth at night and next morning its much better. Yesterday I build a bridge across my ditch and the pipeline we're working beside for rock trucks. I only had wet material and a small stockpile of dry to work with. I blasted in some wet, disked it, let the packer smash the voids out of it, put some dry on, more wet and then mixed a ton of wet and dry together to finish it up. Took about 2hrs to do a bridge 100ft long, 20ft wide and 6ft high over the sewer. At the end of the day the foreman had 3 657's running over it moving dirt for the other crew and it held up fine. This morning they walked a PC750 and PC1250 over it and all was good.
ask some of the drivers coming to the pit if they can bring you some busted up concrete, or demolition rubble, brick,block or whatever. Sometimes that stuff is hard to get rid of for free. Then do as the others have said, dig out the muck, and dump it into the hole. That should solve the problem.
Thank you for those tips. I might be able to convince them to bring demo rubble but that call on fabric was dead on! As this pit is about played out they won't be doing too much other than grading it once we ship the last of our gravel and sand.
did you ever get them to drop off the demo rubble for you? how is it going with that plan?
Nope, right now there is a few thousand tons of bedding sand on top of it, but guarantee the advise will be remembered. We may need it before the pile runs out though, just heard we are going to chase the bottom and there are soft spots/sink holes all around the pit.
Just be carefull of using concrete rubble , as REO and tyres dont like each other . Have you got any logs lying around ? They can be laid side by side and covered with gravel .
logs are a good idea, but what happens when they decompose?
We only use them while access is needed and then they go into the fire .
Naw, no logs around at all and most timbers get saved.