Mass Rock Excavation 1

[michaelljones]

I have a project with a major road designed going through it with a tremendous amount of rock close to the major road. This road is setting a grade I have to use for lot development. Just to get to grade I have 200,000 cu yds of rock I have to blast. With such a large amount of rock what is a fare unit cost and what is a fare crushing cost per ton?

 

[cvg]

blasting isn't the expensive part. loading and hauling the rock away is. it all depends on what you plan to do with this rock pile. once you decide that, you can start to figure the cost

 

[civilperson]

If you provide a fill on site, anywhere from 8.00 to 16.00 per cubic yard cut to fill.

 

[michaelljones]

We will be using the rock on site in fill areas. I am getting a quote of $10 per cu yd. The site is in NC is this a fair cost?

 

[msucog]

$10 to cut and place
or $10 to blast, crush, haul and place?

 

[michaelljones]

$10 to blast and place. All should be 18" and smaller. Additional if need to haul than 1/2 mile.

 

[msucog]

i'd say that's a good price compared to here in atlanta. i've seen it as high as $50/cy for mass rock to blast, cut and place but that's typically for small projects. I don't often deal directly with the owner/contractor contracts but I wouldn't expect to see it less that $20/cy here for a big non-gov't project. crushing to a specified size would be more cost. if they've said $10 to blast to a well-graded 18" and smaller, that sounds pretty good.

I do suggest you have someone onsite to double check quantities provided by the contractor. I'm with a testing firm and we're often the ones observing test drilling and providing the double checking. the contractor provides their quantity to us and we confirm/deny the quantity based on say 50' grid of air-track drilling to the top of rock. seldom do i ever see a project where the contractor isn't trying to rape the owner. based on my experiences, we cut the costs by as much as 50% from what the contractor initially tries to charge for. even if we only save 10% on a project, that's a huge chunk of money that more than pays for our services. and we're not there to cheat the contractor out of money, but a foot here or there adds up to big bucks for the contractor. i've seen projects with as much as a 20' bust in elevation!!! it cut their first blast quantity from 40k cy to 20cy. this point is not directly related to your question but there again, it doesn't make sense to pay half as much per cy when the contractor is going to triple their "quantities".

 

[Boise]

The price will depend on alot of things. Depth of cuts, open or covered blasts,geology....etc...
The cheapest isn't always the best way to go. If your getting more than one price compare drill patterns and explosive selection and contractor references. $10 to drill blast and place 18 inch minus sounds cheap. With 200,000 cu/y there is going to be alot of oversize so who will pay to process all of that? The blasting contractor? Is he going to do secondary blasting or bring in a hammer?

 

[Dozerman56]

I think Boise's on the right track. Depth of the rock cut is one of the most important factors in pricing your drilling and shooting. Withoug knowing more particulars, $10.00/CY is a reasonable price. But your soil techs will need to be proactive. I've seen lawsuits develop over similar situations where the size of material going into the fill wasn't clearly stated and/or adhered to. Don't forget any underground utilities will probably require trench rock excavation as well. Sorry I missed a chance to bid on this one!

 

[Boise]

Dozerman...I just completed 125,000 cu/yds and we did the utility trenches along with the mass. They kept on changing the trench locations so I took out the trenches as a " trench corridor". Just went deeper throughout the width of the roadway where the trenches would go and I got paid the mass rock price. With just under 1 linear mile of pipe, (each),water, storm, sani plus shallows (cable, electric, gas etc) we only had to go back and re-blast about 30 feet of "toe" in the sani.
You did mention material size and lawsuits, this is an item we are fighting over now, however my defence is that the contract and the specs did not mention minimum required material size anywhere.

 

[exploengineer]

Cost will vary quite a bit depending on rock type, cut depths, distance to structures of concern, political climate of neighbors, geographic location, and the required project timeline.

$10 sounds like a resonable price for just drilling and blasting. I've seen projects go for much more. Also, due to the cost of natural gas, fuel, and steel, prices for explosives and drill materials are soaring. Lock them in on the price now without so the price can go for the length of the project.

Frank Lucca M.I.Exp.E.

http://www.terradinamica.com

 

[dirtscience]

michaeljones, I'm in the NJ/NYC area and I generally charge $10/ton or so just for crushing. An additional $4/ton or so to cut, haul and place. I don't do the blasting myself, so I have no numbers.

It's too open ended of a question, though. NC has a varied geology, much like NJ does, so if you're dealing with the hard schists and gneisses you can get to the northwest of NC, vs. the slates and mudstones you can get more easterly, prices can vary by as much as 50% for blasting and crushing, maybe not so much for hauling and placing.

Also, keep an eye on EXCLUSIONS in contracts. Make sure you're dealing with apples and apples. Lots of contractors will lower unit prices by excluding critical things, such as handling boulders too large to crush, heavy dewatering, wrapping shotrock fills with filter fabric, etc.