Hammer What

I made a custom jig to help me tunnel underneath the driveway to put conduit underneath.

I took a 3" diameter piece of pipe that is 6" in length and with a torch/angle grinder I cut 6 large sharp teeth at one end.

On the other end(threaded end) with a combination of bushings/nipples i reduced the 3" down to 1"

Then from the female 1"end of the bushing I attached a 1" Diameter pipe that is 10' long.

Then at the end of the 10' pipe, i welded a piece of 1/2 drill rod (centered) so it will fit in the 1/2 chuck of the drill.

My plan is to tunnel a 3" hole under the driveway which is 10' wide by taking out small amounts at a time, emptying , then repeating.

a) Do you think a drill has enough torque to do this ( Im not plannning on doing this all in one shot, just slow 6" increments)

b) Do you think the 3" steel pipe with teeth will tunnell ok?

Thanks