1 Simplified Method for Estimating Pull Force on Polyethylene Pipe for Mini-HDD Applications

A simplified method has been developed to estimate the pull loads on polyethylene pipe installed by a mini (or midi) - HDD process. The method and associated formulae are based upon approximations to the equations and procedures provided in ASTM F 1962, Standard Guide for Use of Maxi-Horizontal Directional Drilling for Placement of Polyethylene Pipe or Conduit Under Obstacles, Including River Crossings. The objective is to provide a convenient means of identifying potentially problematic mini-HDD installations and∕or to aid in the pipe selection process, in contrast to the extensive planning or analytical investigations characteristic of typical maxi-HDD projects. The proposed mathematical model reflects the major route parameters (bore length, planned bends) and buoyant weight for an empty PE pipe, and also accounts for unplanned curvatures resulting from path corrections in a typical mini-HDD installation.