I placed the Geothermal wells in my lower driveway. The primary feeders need to come up from the driveway, around the front of the house, and into a corner of the foundation. Unfortunately we have some nice old trees in front of the house in the way of where the pipes needs to go underground.
So, the contractor proposed something called horizontal boring. With a horizontal bore, they can go under the trees, horizontally, without damaging the trees. Not only can they go under, they can actually steer the bore left, right, up and down in various ways to dodge the foundation, water pipes, natural gas, etc.
The Horizontal Bore machine, made by Vermeer, is about 15 feet long by 4 feet. Unlike a bore that uses a spinning bit, a horizontal bore essentially pushes through the ground using hydraulic force. The end of the bore has a asymmetric wedge. the wedge can be turned 90 degrees, more or less, to cause the bore to move left, right, up or down as it is pushed through the dirt.
A technician follows the bore head, as it moves through the dirt, with a hand held device (an advanced metal detector) that tells him how deep the bore head is, and its general location. With that information, he helps the operator decided how to run the bore.
The bore was pushed some 90 feet to a hole the contractor dug at a corner of our foundation.
Once the bore pushes through at the far end, they attach a cutting bit(About 6 inches in diameter) to the end. The bit has a swivel, that is then attached to the pipes that needed to be pulled back through the hole. The bore machine then rotates the bore and pulls the drill bit back through the hole, expanding its size from 3/4" to 6 inches, dragging the pipes along the way.
