Blasting some rock- video

[d9gdon]

We shot some rock in the back end of the lake I'm building today that we couldn't rip. We helped to load the holes, it was neat. On the dry holes we used Anfo. On the wet ones we used Hydromite. About 9500 cubic yards. I was about 1/4 mile away so video is not great, it was shot from my phone I've had for about 6 years.

I forgot to take a video of the aftermath. Piled it up pretty good. A couple of rocks landed about 20 feet in front of me.

Yes it did knock the power line down but they told us it was dead and to call if it went down.

http://www.youtube.com/watch?v=2cgrFHhhqjI&list=HL1353462849&feature=mh_lolz

 

[DerelictTexture]

Good looking shot.

You want to be real careful about being out in the open around large blasts. I've seen high flying nuggets come down 20 to 30 seconds after the shot....straight down like a missile. If you were wearing a hard hat...it would go right through and probably stop somewhere around your liver.

Or something like these poor people ...a shot that he loaded and fired took his girlfriends arm off....the fella was in the biz for his entire life...not a rookie. His dad was a local legend in the biz.

http://youtu.be/FRcqrHZdYog

http://youtu.be/9nzFTrmfpp0

Guys that have been around near blasting misses... will crawl under something big and heavy and curl up in a ball...then they don't come out for a good while after the shot goes off.

here's a few from the days when I was still doing that sort of thing..

http://adventuresinmikeslife.blogspot.ca/2012/03/sea-to-sky-overture-blasting-video.html

 

[ben46a]

18000 ton of shotrock made in 2 seconds... Good job. How long of a collar did they leave in the top of the holes? We try to leave 8 feet, keeps the flyrock down.

 

[DerelictTexture]

Their collar height is going to depend on a few different factors..

Is the rock soft, hard or something in between?

What explosive is being used?

Does the rock tend to "fly" when it's shot?...some does and other types are relatively "dead"

What is the borehole size and drill pattern?

Is ground vibration going to be a factor? ( cracked house footings, broken water lines etc )

Is there anything nearby to hit?

in a large quarry...hit it hard but don't scatter the material....out in the public world, you can't afford to launch rocks into outer space and risk hitting something expensive...or a worker bee. God forbid you should hit the bosses new pick up truck.

Blasting is like the Goldilocks thing....too little, too much...and just right. The trick is, the "just right" formula keeps changing with changing conditions.

My question for d9gdon is, do you know if the shot was a "Sinking cut/box cut"? in other words...did it have a free face to shoot to ( didn't look like it ) or did the blaster wire it to launch several holes really hard...and the rest of the shot piled into the cavity left behind?

 

[d9gdon]

How long of a collar did they leave in the top of the holes? We try to leave 8 feet, keeps the flyrock down.

Only about 4 feet, as I helped load them. The holes were only 11 feet deep and on the wet ones we used two and a half salami's (hydromite) on average. I think they're about 36" long. Probably a 4" hole, maybe 5"? Salami's had no trouble going in. On dry holes, we used about a bag and a half (ANFO) in the holes.

Is the rock soft, hard or something in between?

It was limestone, not hard like granite or basalt. He said the shale down below would absorb a lot.

Is there anything nearby to hit?

Not really, closest house was 3/4 mile away.

My question for d9gdon is, do you know if the shot was a "Sinking cut/box cut"? in other words...did it have a free face to shoot to ( didn't look like it ) or did the blaster wire it to launch several holes really hard...and the rest of the shot piled into the cavity left behind?

I had taken it down to rock that I couldn't rip with a D6T. He blasted so that it piled it up in the cavity that it blew. He is not timid with the explosives. Vietnam Vet that blasts for the surrounding counties' crushers.

 

[DerelictTexture]

Thanks for the answers. Yup, limestone sometimes needs more juice to get it to break properly...the natural softness and small fissures in the formation can absorb quite a hard hit.

4 or 5 inches is a pretty big diameter for an 11 ft hole....any chance it was more like 2 1/2 or 3 inches?

Do you remember how far apart the holes were?

Was there any way to pump out the wet holes...or were they "making" water?

Just curious...you guys had a good looking shot that produced nice results...I'm interested in how it all came together.

 

[d9gdon]

Thanks for the answers. Yup, limestone sometimes needs more juice to get it to break properly...the natural softness and small fissures in the formation can absorb quite a hard hit.

4 or 5 inches is a pretty big diameter for an 11 ft hole....any chance it was more like 2 1/2 or 3 inches?

Do you remember how far apart the holes were?

Was there any way to pump out the wet holes...or were they "making" water?

Just curious...you guys had a good looking shot that produced nice results...I'm interested in how it all came together.

The top layer was the hardest, then about 3 ft below that was another one just like it. In that 11 ft there were probably 7 - 8 layers and it was making water.

Don't know, the holes had to be at least 3 inches. Those salami's were at least that big. I still think they were 4".

And the holes were 10' on center and he had some extra ones on the edges. My compadre' said he had drilled those extra ones on the edges at an angle, which to me would blast the edges down and away so it would pile up. I didn't see him doing those.

Here's some really bad video of the results:

http://www.youtube.com/watch?v=UyYRJFvcGhE&feature=youtu.be

I'll try to get some better video on Saturday...

 

[DerelictTexture]

That broke up nicely!...I see the power company in the background doing a little repair work.

You are building a lake,is that right?...where is the water coming from to fill it up and replenish it in the summer heat?

What machine are you going to dig out the lake with?

Where is the blast rock that you dig out going to?

 

[Birken Vogt]

I am curious how you assure when doing this sort of work that all the holes went off and somebody doesn't hit some explosive that failed, when digging the rock with a machine.

 

[DerelictTexture]

A good/conscientious blaster will walk through the shot after and look for evidence of holes that didn't go off. It depends on the initiation system...it can be really easy to see, or take a bit more work.

The first thing to look for is large chunks of rock that didn't break as expected. This isn't a perfect indicator because it could be cap rock sitting on top of a seam...and everything underneath is nicely smashed.

Left over nitroglycerin based dynamite is dangerous to dig into. Emulsions and Anfo less risky...but still needs special attention. Some of the emulsion cartridge products are famous for not going off, even in perfect conditions.

If the primers are still intact ( detonator and primer charge combination ) that's very dangerous and life threatening...you want to approach that issue with your best professionals.

Excavator operators who work with blasters all the time know what to look for ( the ones who have long careers )

 

[d9gdon]

That broke up nicely!...I see the power company in the background doing a little repair work.

You are building a lake,is that right?...where is the water coming from to fill it up and replenish it in the summer heat?

What machine are you going to dig out the lake with?

Where is the blast rock that you dig out going to?

You can't tell it from that video but that's in a wet weather creek bed. It has plenty of runoff. I'd say around 1200 acres. We're in a dry spell now but there's still water running underground on top of that hard layer of rock.

I've already finished the dam and have excavated about two thirds of the bowl. It already has about 18" of water in it. I'm using a 450 Hitachi and two 725 mud trucks, a 623B scraper (till I hit mud), a D6T , a 953 and a 544K rubber tired Deere, and a belly dump. Lots and lots of silt there as it was farmed all around it in the past. I should be at about 103K cu yards of excavation when finished.

We're working on a deal with the county to use the shot rock. They have a crusher to run it thru after we get it out of the hole. I've got some roads to build on the place anyway.

 

[DerelictTexture]

Sounds like fun, is this a contractor crew or the neighborhood gang pitching in...or all your gear?

 

[gert2012]

various movies of underwater blasting http://www.isaris.nl/ppm/dredging/tags.php?tag=734 very spectacular

 

[DerelictTexture]

Great collection of videos, gert2012. I forwarded the link to my construction friends and put the link on my blog. Thanks for posting that!

Mike

 

[d9gdon]

Sounds like fun, is this a contractor crew or the neighborhood gang pitching in...or all your gear?

This one's both, contractor crew and owner are the same on this place. We're gonna build a couple of houses on the acreage.

 

[Kman9090]

http://www.youtube.com/watch?v=tHTzRfWOOVE

 

[d9gdon]

Nice shot. How many yards in that?

Sounds like the volunteer firemen in the community heard it too from the background noise.