Any one have experience drilling rock ?

[peakbagger]

Looks like I will be needing to deal with ledge and or boulders on my new driveway. My trusty jack of all trades FLU 419 loader backhoe also has a built in hydraulic power pack with a 50 foot hose reel to run hydraulic tools. It also came with a hydraulic jack hammer and hydraulic rock drill (that looks like a jack hammer). Depending on how much ledge is encountered and how fractured it is, I may have a go at it with the drill, slow "dynamite" (high expansion grout)and the ledge hooks on my backhoe . Unlike blast track equipment, the drill is not set up for air injection and uses solid drill bits. I can tap off the air system for compressed air and am thinking I will just put on mask and blow the holes out occasionally. In order to use the grout I need 1 -7/8" holes. Ifs the ledge is extensive I can hire a drilling and blasting firm but its 10K just to mob and demob plus a pretty hefty fee per day. Odds are I may need one for future foundation and will just bite the bullet.

So anyone have any suggestions?

 

[zrock]

I would get in their with the jack hammer and see what happens.. You may find its soft and comes right apart.. If you use the drill your are going to have to stay onto of the hole clearing as that dust can jam the drill in their tight and you will be leaving it in the rock. First thing i would do is dig all around it and find out exactly what you are dealing with.

 

[EbS-P]

How deep will you need to drill?

 

[rocky99]

I used to have a blasting license in NY. Would always rent an air compressor and jack hammer type drill to drill 2" holes into rock.

 

[peakbagger]

Not really sure on depth. Usually granite ledge is fractured for several feet before its gets solid. It is usually breaks off in sheets. I think the trick is to drill down through sheets and then use my ripper bucket to break the sheets up. I dug about a foot deep trench about 50 feet long with just the ripper teeth about 5 years ago. It looks like one of these https://rocklandmfg.com/product/rock-ripping-bucket/

The original military SEEs, did not come with them, they had a single ripper hook that coudl b attached to the bucket but at some point the military allow units to special order the ripper buckets.

I used to use slow dynamite on concrete for projects at the papermill and it worked pretty slick but if there was rebar in it, it required more holes. Berlin NH which sits on shallow granite replaced a lot of waterlines about 15 years ago. The first year they had a blasting contractor blow the ledge in the trenches but they got too many complaints and insurance claims from surrounding houses built in ledge so they switched over to a combination of a big ramhoe drilling and slow dynamite. They did multiple miles of roads over a several yar period.

 

[EbS-P]

Not really sure on depth. Usually granite ledge is fractured for several feet before its gets solid. It is usually breaks off in sheets. I think the trick is to drill down through sheets and then use my ripper bucket to break the sheets up. I dug about a foot deep trench about 50 feet long with just the ripper teeth about 5 years ago. It looks like one of these https://rocklandmfg.com/product/rock-ripping-bucket/

The original military SEEs, did not come with them, they had a single ripper hook that coudl b attached to the bucket but at some point the military allow units to special order the ripper buckets.

I used to use slow dynamite on concrete for projects at the papermill and it worked pretty slick but if there was rebar in it, it required more holes. Berlin NH which sits on shallow granite replaced a lot of waterlines about 15 years ago. The first year they had a blasting contractor blow the ledge in the trenches but they got too many complaints and insurance claims from surrounding houses built in ledge so they switched over to a combination of a big ramhoe drilling and slow dynamite. They did multiple miles of roads over a several yar period.

I’ve spent hours watching Demolition Dave on YouTube. The expando works well it’s just not as satisfying for the viewer even with a time lapse. https://youtube.com/@demolitiondavedrillandblast?si=7s4oQShvtjJ9zNkK

 

[EatenByLimestone]

Can you use the talus pile to help smooth everything so you don’t have to excavate as much?

 

[peakbagger]

I have plenty of place to fill. If I dont hit ledge its about a 1000 yards that has be moved.

 

[EatenByLimestone]

Is it easier to just bring in fill and not excavate?

 

[peakbagger]

Unfortunately not, In spots the driveway has to be dug in several feet deep. Hauling in fill is expensive compared to moving it around on site.

 

[peakbagger]

No ledge so far but a lot of dirt needs to be moved. Lots of small and medium boulders but no monsters yet.