What is a Horizontal Directional Drill?
The HDD method tunnels beneath surface obstacles and then pulls the pipeline back through the underground tunnel, leaving the surface undisturbed. The tunnels are typically drilled to depths ranging from 25 to 100 feet below surface obstacles, depending upon the location, pipe characteristics, and subsurface conditions. The HDD installation involves four main steps: • Pre-Site Planning Extensive pre-site planning is required to determine if the HDD method is technically and geologically feasible. A topographic survey is performed along the proposed drill site to ensure adequate surface area is available to conduct the drilling process. In addition, a geotechnical investigation is conducted at each drill site to determine the subsurface conditions. Using the data from the geotechnical investigation and topographic survey, a specific drill path is determined. • Drilling the Pilot Hole Once the entry location, exit location and trajectory have been determined, the next step is the drillin
