USING A GRAPHICAL METHOD TO UNDERSTAND THE INFLUENCE OF CRITICAL GEOTECHNICAL PARAMETERS ON HORIZONTAL DIRECTIONAL DRILL (HDD) DESIGN

The horizontal directional drilling (HDD) industry has experienced tremendous growth in recent years thanks to its technical and socio-economic advantages over traditional open-cut (trenching) methods. Many technical challenges that have hindered open-cut pipe installation methods can now be overcome by using various graphical models to estimate feasible HDD alignment geometries, thus increasing the probability of HDD success. However, the design requirements and risks involving HDD are different from other civil engineering practices, since HDD designs are heavily dependent on a thorough understanding the soil, rock and groundwater conditions along the alignment. Misunderstanding or oversimplifying the critical geological, geotechnical, and HDD drill fluid parameters can lead to unsophisticated HDD drill path designs which may not accurately reflect or quantify the risks involved. This presentation discusses the influence of certain engineering parameters that are critical for the design of an HDD project using a proprietary graphical tool, and will emphasize the importance of deciphering the site conditions and obtaining relevant design parameters at the early stages of a project.