Rock Excavation - Contractor Talk - Professional Construction and Remodeling Forum

rshackleford · 06-15-2009, 09:26 AM

i am installing an 80 mile rural pipeline and have ran into shelf rock. the particular shelf i am on now is 25' long and 5' thick. our trench width is 3' wide. i think we might run into this 15 times through out our project. our cover depth is 7'.

what are the recommendations for handling this rock? i have been told others are using hammers or breaker balls.

JDavis21835 · 06-15-2009, 08:11 PM

Type of rock may make a huge difference here. No options for drill and blast?

rino1494 · 06-15-2009, 09:12 PM

For that little amount of rock, hammer away.

Bigger is always better when hammering.

rshackleford · 06-15-2009, 09:55 PM

could i use a headache ball?

here are some pictures of the rocks torn out of the ground just a little ways away.

tgeb · 06-16-2009, 03:10 PM

I think would try a hydraulic hammer on that and see how it goes.

It's hard to tell from a photo, but that stone "looks" like it would yield nicely to a hammer.

rshackleford · 06-16-2009, 03:12 PM

how about a headache ball?

tgeb · 06-16-2009, 03:55 PM

I personally have never used one.......But give it a try and see how it works for you. Could be the ticket.

rshackleford · 06-16-2009, 03:57 PM

i have broke a little concrete and asphalt with a hammer, but never rock with any tool. i think a headache ball would be the cheapest.

piercekiltoff · 06-16-2009, 08:19 PM

Looks like a sandstone material to me - breaks in layers, looks like it was formed in sheets.....If the layers have been twisted/warped, it's known as a foliated metamorphic rock - metamorphic meaning that it has been changed by heat/pressure, such as being buried deep underground, subject to tectonic actions, etc.

My experience is that metamorphism tends to cause rocks to get harder, but in hammering situations, harder rocks tend to break with better fractures....of course, I work with big down hole pneumatic hammers.

rino1494 · 06-16-2009, 10:14 PM

Quote:

Originally Posted by rshackleford

i have broke a little concrete and asphalt with a hammer, but never rock with any tool. i think a headache ball would be the cheapest.

Trust me, you are wasting your time. A headache ball may break the top foot or so, but it won't break the bottom. Also, it will be dangerous for pieces of rock to be flying. I've hammered thousands and thousands of yds of rock. The only regret I ever made hammering, is using a machine that is too small.

Stock · 06-17-2009, 04:21 AM

What size equipment do you have???? ,for accuracy I THINK a hammer would be the best option for you ,now if you have access to an atm like some undesireables over here you can get rock saws, drop balls ,one of these
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Name: HCMRB EX1200 2.jpg
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but for the work you are at of which I have some experience ,I have worked with most types of rock from granite to black limestone to sand stone to slig/pencil and I still say a hammer is the way to go .May also be known as a hoe ram???

Stock

SDG · 06-22-2009, 10:45 PM

Just finished doing a lake 15' deep, digging thru cap rock. Used a Hitachi 850 with a rock bucket, twin tiger tooth and make sure you have a welder onsite

piercekiltoff · 06-23-2009, 08:55 PM

You guys get to do all sorts of cool stuff on the other side of the country. We'd have to spend $200k on permits and it'd take 20 years to get them in order to dig a lake here.

rshackleford · 06-24-2009, 06:31 AM

i got some samples of the rock yesterday. i was able to break some chunks off with a 3lb sledge. it is definitely sandstone. it is about 5 feet thick. i can set it on a concrete sidewalk and break it into small pieces with the same hammer. i didn't work very hard with the hammer, didn't swing it with too much force.

D-Excavator · 06-27-2009, 11:51 PM

I would suggest Hammer,dig,hammer,dig. If ya get enough of that material, well I am sure we could all find someplace for it? Some folks just aren't for hammering, with a little finess and consistence you can make short work of it.