Drilled Shaft Production

[asdf]

Anyone have an idea of what the production rate for drilling a 6' diameter drilled shaft through 8000 psi concrete would be?

 

[Qshake]

I'm guessing this concrete is pretty old and so it will be very hard (as you'd expect!). It should pretty much like drilling a 6' rock socket in 20 ksf limestone. You can check with means construction data for production rates on this.

If the concrete is not very old and still green it could move right along.

Regards,
Qshake

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[DRC1]

8000 psi concrete is pretty hard stuff. It is also reinforced. Talk some drilling outfits like Haywood Baker. The bit life is probably not very long and changing bits will significantly impact production (as well as cost). Another concern is reinforcing. Usually high strength concrete is heavily reinforced. This will also have a significant impact. You really need to talk to driller to get a good idea of what is involved.
Good Luck

 

[Focht3]

That's a big cut. I agree with the comments so far. You might "think out of the box" on this one; perhaps some high pressure air/water jet could be used to essentially erode out the concrete, allowing access to the rebar with a saw or grinder. Once through the concrete, the pier rig would be free to use normal drilling techniques.

If you use a pier rig, you are likely to damage portions of the slab in the vicinity of the six foot hole. In that case, jackhammering would be preferable to using the pier rig -



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