Underground Wire Tunnel Video
First, create a small trench perpendicular to the sidewalk to create some working room for the pipe. Once the trench has been cut, use a sledge hammer to drive the PVC pipe a few inches into the ground. Twist the pipe to break off the dirt and remove the pipe. The end will have dirt in it from under the sidewalk. Take another small diameter pipe or rod and drive the dirt out of the chiseled pipe. Continue driving it in a very inches at a time until you have reached the other side.
You now have your tunnel to run the cable or wire under the sidewalk. If you leave the PVC pipe under the sidewalk, it will serve as a nice conduit if you need to run another wire at a later date.
Tim received an email from a reader about a water line under a foundation. Read about the solution in the September 6, 2011 AsktheBuilder Newsletter.