Blasting heavily faulted Granite

Another rocky home site excavation in Mt. Martha, luckily for the owner and builder 90% of the weathered and faulted Granite on this site was able to be removed using the hydraulic hammer on the large excavator. Just when they were on the home turn the yield slowed and it got a lot more difficult. High explosives to the rescue again to get the excavation back on track and finished in good time without and problems or complaints.

[@whotknots]

Dave watching the excavator work in reasonably close proximity to your ute reminded me of an incident involving a similar scenario that occurred a couple of decades ago. I was acquainted with a local station bloke up near the NT border where I was living at the time who was rougher than Rafferty's rules and had just purchased a brand new 4WD. Shortly after the aforementioned acquisition word got around on the bush telegraph that he had driven his shiny new vehicle out to a place where he was messing about with an excavator. Apparently the erstwhile earthmover started his digger and promptly swung the boom smartly around with impressive flair to begin a bit of digging but was interrupted by a sickening crunch. At that point rotation abruptly stopped and a brand new 4WD became a mangled wreck under the rear of the turret!

[@demolitiondavedrillandblast]

I guess his day was off to a bad start then hey!

[@billraccio3835]

Love how you called yourself doctor Destruction in one video!!!

[@demolitiondavedrillandblast]

Thanks for tuning in to Demolition Dave's Daily Dose of Destruction.

[@paoemantega8793]

That is some skillful proximity blasting right there, thank you for the video, keep em coming

[@demolitiondavedrillandblast]

Thanks for watching, more than 100 more on my channel and a new one coming very soon. Please subscribe.

[@oxtoolco]

Dave, How do you determine the depth to drill the holes just by looking at the topside of the rock? I would guess that drilling something like 60% through would be optimal but if you can see underneath how do you do it? Cheers, Tom

[@demolitiondavedrillandblast]

When you want to break a rock of known size, then you would drill about 2/3 of the way through, for a massive rock that you just need to take a piece out of then you would drill a little deeper that you need to break.

[@oxtoolco]

@@demolitiondavedrillandblast I guess my question is how do you know the size? All the rocks I have removed by hand have always been bigger that expected when you finally get them out. I imagine poking the drill out the bottom of the rock is not what you want. Thanks for the answer. Cheers, Tom

[@hermannstraub3743]

@@oxtoolco Hy Tom nice to see you here. I reckon as you poke through the first time you now exactly so then drill not as deep.

[@flantc]

Such a cool job. Reminds me of a guy I meet who was a “ordinance disposal engineer” in the military. He explained it as being given 25kg of C4 and being told to find discarded munitions and blow them up. Of course being young and inexperienced he once lost a good part of his hearing in one hear because he set a charge and the realized he had 20 seconds and was in the middle of a completely flat expanse with no where to find cover. He was lucky to only lose some hearing.

[@demolitiondavedrillandblast]

25 Kg of angry playdough, there would be a few good bangs in that!

[@scruffy6151]

As a kid we would dynamite stumps and big rock out to clear land for fields. Watching you brings back good memories.

[@leonmarut917]

thanks for the extended version dave

[@ChrisB257]

That was one big mother of a slab/slabs! Job well done Dave.... mostly nice small chunks :)

[@demolitiondavedrillandblast]

Yeah, a guy came buy and expressed interest in getting some big pieces... sorry about that.

[@nigelkavanagh2048]

Jee Dave that drill eats that up fast.Good job man.

[@demolitiondavedrillandblast]

Started the new job with new sharp drill heads and the rock was not all that hard, but yes it is the right tool for the job.

[@robertgeorgewerner]

Thanks for filming the clean up too. I enjoyed seeing the results of the blast. What do people do with the spoil? I assume it's too hard to crush for aggregate.

[@demolitiondavedrillandblast]

Hi Robert, I believe all of the small bits ended up being used to build a drive way at another site and the big bits used for landscaping around an ornamental lake on another site.

[@ReturnMoreFire]

I like the homemade dust collector for that hammer drill 👍🏻👍🏻

[@demolitiondavedrillandblast]

I would not be without it Chum.

[@bigredracer7848]

521👍's up guy thanks again for taking us all along with you for the day at work

[@demolitiondavedrillandblast]

Thanks for coming Scott.

[@Joshua79C]

One of those literal "stuck between a rock and a hard place" jobs.

[@briangardiner1015]

Another fine job. Until you said it was granite it almost looked like a faulted basalt to me, but I'm not on the ground. I like the down feed method of the rock drill operator using his leg. How do you determine your burden and spacing?

[@demolitiondavedrillandblast]

Hi Brian, yeah it was funny looking Granite, lots of iron staining through it, determining B&S, OK it is always less than the hole depth, preferably hole depth is >1.5x burden, hole spacing= burden or up to 1.2 x Burden, depth of stemming = 20 - 30 x hole diameter. Hole diameter is chosen to fit the desired amount of charge and suitable stemming height. The B&S on this one was 700mm for the 1.8m holes, could have been 1m or even 1.2m but that would have meant the the explosive mass per hole would have to be doubled or tripled and that would have been too much from a vibration management perspective.

[@jerrystott7780]

I do enjoy watching the precision involved. Nice job.

[@jerrystott7780]

P.s. Does holding down the drill with your leg cause tendon problems like vibration can in your hands?

[@demolitiondavedrillandblast]

Thank you.

[@demolitiondavedrillandblast]

Jerry Stott - no problems yet and I've drilled about 35,000m

[@jerrystott7780]

@@demolitiondavedrillandblast that was one thing nice about drilling in a hard rock mine, pneumatics held the drill up and pushed it in.

[@demolitiondavedrillandblast]

@@jerrystott7780 - I need one of them.

[@adamedward205]

That stuff really shattered up nicely, if you do get a misfired single hole, how would you know? Or would it not be that dangerous to dig through?

[@demolitiondavedrillandblast]

Hi Adam, thankfully this is a rare occurrence, the most common cause of a missfire when a shot is covered with a large amount of soil like this is when a large rock in the cover crushes or cut through one of the plastic shock tubes that join all of the holes together. You would always do you best to make sure that the cleanest soil that you have goes on first so as to prevent this. This kind of failure is very easy to detect by employing the simple practice of using "witness tubes" from the last hole in every row - the excess length of tube on each detonator that would otherwise be rolled up or cut of. A piece of electrical tape is put over the end of each tube and the initiation shockwave travelling down the tube punches a hole through the tape and indicates the the blast has propagated to the end of each row. This could be all good but you could still have a detonator fail down the hole, this is rare and not always obvious, first indication of this may be an area of rock that is stuck or not broken or unfired explosives found among the broken rock, this is when it gets ugly and you have to work with only hand tools and compressed air to try and work out what has gone wrong and make it safe. The most dangerous part that you would be worried about when digging through the rubble is unfired detonators as they sure can explode if they suffer crushing or impact, the packaged emulsion explosive or anfo present little hazzard. I'm always watching closely during the dig out phase.

[@adamedward205]

Thanks, was always curious how you dealt with that side of stuff, hand tools and digging through sure sounds a good reason to take a lot of extra care getting it set right!

[@frozenjoe6313]

Question please. You have heard of non-Newtonian fluids, right? and there are a variety of substances in that category. Stemming of blast hole might benefit greatly by using nonnewtonian fluids first in conjunction with peagravel.or 1/4 inch crushed gravel It might greatly reduce noise and steming requirements . the slow Nonnewtonian goo should flow into any tiny cracks and crevices and avoid most decoupling in the blast hole. What do you think?? Oddly enough, corn starch and some water is nonnewtonian and dirt cheap and biodegradable.. .. and none regulated....might work better with det cord.....Your thoughts /

[@aplummer57037]

So, how do you manage vibration so near to neighbouring buildings? Do you put ground monitors down?

[@demolitiondavedrillandblast]

Hi Andrew, there are many thing that effect blast ground vibration, good blast design minimises the jolt. The main factor is the use of millisecond delay detonators - this technique ensures that all the holes do not fire at the same time but they fire sequentially, in this case the front rows of holes are time spaced at 17mS interval, the row behind also @ 17mS but it has a 42mS delay offset behind the front row, end result is you can fire a large number of hole sequentially in one blast without any holes being time spaced closer than 7mS (7mS is the critical figure). Older, simpler methods (still used by my competitors) just fire all of the holes at exactly the same instant - this causes a mighty big jolt as you might imagine. So the most important control method is limiting the maximum explosive charge mass firing at any one time by inserting very short time delays between holes, other control methods are making sure that where possible each hole has a free face to push the rock out, inclination of the holes, V.O.D of the explosive and other minor factors. I have a precision blasting seismograph and vibration prediction software that I can run on my phone that has proven very accurate, might do a video on that sometime.

[@steffentangen8039]

Search for nonel thats the system they used here. Probarly a youtube video explaining it.

[@dawolf7784]

lol you turned those massive pieces of rock in to gravel ! ❤❤🐺🐺🐕🐕🐺🐺❤❤

[@demolitiondavedrillandblast]

That is what I do.

[@sighpocket5]

Nice!!!

[@lenmiller6408]

whats the little blue dust collector ? something u created or bought ?

[@demolitiondavedrillandblast]

The blue thing is a cyclonic separator - canberradiamondblade.com.au/product/cps-24-50-supa-separator-floorex/ I have made better high efficiency separators but they wear out quickly because the stone dust is so abrasive.

[@realaussiemale567]

Where was this job? Looks close to Pt Phillip Bay, maybe Frankston area?

[@demolitiondavedrillandblast]

Mt. Martha

[@janeblogs324]

What country? SA?

[@markusayt]

What would the shot look like without the soil cover.? Would you have flying rock chunks or just a lot of dust? It seems like the charges are sized to break the rock but not launch them to the moon. 😀

[@demolitiondavedrillandblast]

Oh, it would have launched in a disastrous manor.

[@gerry343]

How do you know how deep to drill for each shot?

[@demolitiondavedrillandblast]

You drill a little deeper that the desired excavation level and that will usually get it out.

[@MiniMachines1]

Don't you use blasting mattress down there? So much quicker that covering it with dirt again, doing the same job so many times

[@demolitiondavedrillandblast]

Hi, Thanks for watching MM, I like you channel and just subscribed. I do have a big pile of blast mats but I don't often use them as I find the soil provides a higher level of protection and cuts the noise to almost nothing and no noise = very few complaints. Hundreds of blast mat shots on this old video of mine - kzbin.info/www/bejne/jHSwm5SPm7qagbM Please subscribe and you videos will be recommended to my viewers and mine to yours - David (from near the bottom of the world)

[@MiniMachines1]

@@demolitiondavedrillandblast aha can see that its much less movement on the dirt than with mats, didn't think about the sound so good point 😊 only looked like it took a lot of Ekstra work/time to cover up with dirt,but I see in your videos that you do a lot of blasting in residential areas. Found your channel yesterday and did subscribe and have enjoyed your videos with my morning coffee today ☕ would love to be able to blast some rocks and bedrock up here, but it's 6 years in school to get the certificate to blast 😒

[@demolitiondavedrillandblast]

Wow... 6 years to get a blasting license... that is astounding! It does take more time to cover with dirt, but the dirt is already at the site, I would have to bring a truck to transport the blast mats and a driver = more cost and I used to spend a lot of time repairing blast mats, which is very difficult work.

[@michaelexman5474]

Thats a guy that takes his respiratory protection seriously

[@demolitiondavedrillandblast]

The stone dust has killed my competitors that did not take it seriously enough.

[@cormackeenan8175]

Where do you go to school to learn blasting? Are there night courses in the local tech.?

[@demolitiondavedrillandblast]

Yes, I did a night course at a collage.

[@duanewhite3184]

Looked like the earth farted 😂

[@StarScapesOG]

It's amazing how it just degraded into such small chunks...

[@demolitiondavedrillandblast]

Devastated wasn't it!

[@StarScapesOG]

@@demolitiondavedrillandblast wonderfully so!

[@thangphamvan611]

what happend if there are misfire in some holes?

[@demolitiondavedrillandblast]

Hi, thanks for watching. We are using down hole delay detonators, with this method missfires are very rare compared to older methods such as detonating cord and surface delays. I'm always watching for missfired explosives when the shot is being dug up. It is possible to have a partial missfire with a covered shot like this if part of the shock tube that connects all of the detonators gets damaged during the covering operation, this is easy to detect as we always use the witness tube technique to indicate that the shot has progressed all of the way through the sequence of holes.

[@mattywho8485]

If ol' Stuey had another job with a wet area that needed a driveway, that shitty blasted rock chunk would be perfect!

[@demolitiondavedrillandblast]

That is exactly what it was used for.

[@rzasaglam7358]

How many specific charge?

[@demolitiondavedrillandblast]

at kzbin.info/www/bejne/npO5Y62hd9KJp8U I tell you.

[@rzasaglam7358]

@@demolitiondavedrillandblast thanks you for answer. good job! congraculation 👍

[@rbmccloskey]

Why do you drill out by hand? Why not larger holes with greater spacing? Say: 3" diameter @ 12' deep on a 5.0' x 5.0 pattern.Yes, I do drill in shoot; in New Jersey and New York City.

[@demolitiondavedrillandblast]

Very good reasons for small diameter holes for most of the work I do, mostly close proximity work. It comes down to getting good fragmentation while not exceeding the maximum allowable vibration limits at adjacent homes (much tighter than USA limit). You can only do this with a small charge mass per delay period. Big diameter holes are no good when you only want a very small charge. I have two machine mounted drills that you can see in my other videos, thanks for watching.

[@dennisphoenix1]

The work in braking up and removing all that rock is paid for in the view that the home owners will get .

[@demolitiondavedrillandblast]

Sure is, the sea views here are worth a lot, would not be a home on this street under a Million Dollars.

[@albertbatfinder5240]

Only thing that would make your job cooler would be to ditch that siren and play Stevie Wonder’s “Master Blaster” as a warning. Cranked up to 11. “Didn’t know you... Would be jammin’ till the break of dawn” Reggae improves every work site.

[@damodoesall6240]

Nothing like a busy road next to site

[@demolitiondavedrillandblast]

No problem when it is all well covered Damo.

[@joewoodchuck3824]

I wonder how much $ blasting costs.

[@demolitiondavedrillandblast]

Not as much as it should.

[@joewoodchuck3824]

@@demolitiondavedrillandblast Meaning it's not a well paying occupation?

[@demolitiondavedrillandblast]

@@joewoodchuck3824 - No, it pays very well Joe, but my costs are very high also, cost of materials, cost of maintenance, wear and tear on me etc.

[@landlifem5872]

@@demolitiondavedrillandblast Just for all of us watching and wondering, can you give us an average ballpark figure per hole? I've absolutely no idea if it would be $100 or $1000 per hole.

[@demolitiondavedrillandblast]

@@landlifem5872 - From about $60/hole total cost, depends on lots of lots of variables.

[@bradentyrrell1444]

Why is this so entertaining

[@demolitiondavedrillandblast]

Because it is blowing stuff up???

[@bradentyrrell1444]

Demolition Dave Drilling and Blasting that is very true

[@r.awilliams9815]

Like Dave said, blowing stuff up is part of it...personally, I just enjoy seeing a skilled craftsman go about his work, whatever that might be.

[@michaelexman5474]

yea i think we may know each other from way back

[@demolitiondavedrillandblast]

No, I don't think we do Michael.

[@neville3151]

What a dream job...getting paid to blow things up.

[@demolitiondavedrillandblast]

There are good and bad dreams Neville.

[@PatGilliland]

Pulverized it.

[@kmagnussen1052]

The primary job is drilling holes.

[@demolitiondavedrillandblast]

That is the bit that takes most of the time

[@cormackeenan8175]

What I like to see when they have the right size of digger for the job.

[@joewoodchuck3824]

I think they're supposed to be called degroes instead of diggers now.

[@kevinbyrne4538]

Wow. You reduced that granite ledge almost to gravel.

[@jesseweaver_fuyt]

I always like seeing how others countries load holes close to houses. The company I'm with we just use a full or half a stick of 2"×16" and pop the bottom and crack up the rock.

[@demolitiondavedrillandblast]

That sounds similar to how we do it, I'm generally using 1" or 1.25" and smaller holes though on house sites, make sure you have a free face, keep the powder factor low, no problems. The biggest issue over here is the shrinking of land sizes and the increasing building density, some home sites now as small as 320m2... you would not be using a 2"×16" on these sites.

[@demolitiondavedrillandblast]

Post some Video Jesse

[@alexmarshall4331]

You have radar!!👉💣👈

[@demolitiondavedrillandblast]

I have all kinds of high tech gizmology Alex.

[@alexmarshall4331]

@@demolitiondavedrillandblast you mentioned the weather..and water in the bore holes...meteorological radar too!! thanks for getting back..1st time I've seen one of your postings..loved it!!👉⚠️👈