Educate Yourself:             

There are two frequently used methods when it comes to underground utility construction and getting pipe, conduit, etc. from one point to another: Directional Boring and Open Trenching/Cutting.   There are many variables and conditions to consider when determining which process to implement for a project. 

Directional Boring:

          This method is often referred to as “Trenchless Technology”, Horizontal Directional Drilling (HDD), or Directional Boring.   It utilizes special machines that install underground conduit with virtually no impact to the surface area, minimum disruption to traffic flow, landscaping or structures. 

boring under road

The Directional Boring Procedure:        

Planning:  

Every project should begin with careful planning.  There are many conditions which should be considered and planned to help the project go smoothly.  Ground conditions are determined, existing utilities in the surrounding area are positively located, a bore profile is plotted and safety and environmental issues are considered before work commences.

Pilot Hole:

Once the planning is complete and the equipment is set in place the process begins with the drill machine pushing a bore head connected to a hollow pipe into the ground at an angle.  A pilot hole is created by the drill bit and as it is pushed into the ground by the machine down the bore path, additional drill pipe are added to the drill string.  This process is continued until the bore head comes out of the ground at the end of the bore. 

Steering the Bore Head:                                                                                                                                                                                   

The drillhead location is monitored at all times by the use of a transmitter located in the drillhead sending information to a receiver on the surface.  At the surface, a receiver is manually positioned over the transmitter (Sonde), which decodes the signal and steering directions are relayed to the operator of the drill machine.  From the drill head flows a drilling fluid which is generally a mixture of bentonite clay and water.  Boring is accomplished through the cutting action of the jet of fluid and/or a rotating drill bit.  The drill fluid cuts the soil, suspends and carries cutings out of the bore hole, seals the bore hole, lubricates and cools the pipe. 

Reaming and Pullback:                                                                                                                                       

When the bit reaches the exit pit, it is then detached and a reamer is attached to the drill string.  The reamer is then pulled  back through the pilot hole while rotating the drill pipe with as many passes as needed to  create desired hole diameter to accomadate size of product to be installed.  Once the bore hole is the correct size for the product to be installed, the product is then attached to the reamer and pulled through the hole.  Throughout this process, bore fluid is continually pumped into the hole to ensure that the hole is sealed  with no void being left between the pipe and the native soil.