Large Diameter Steel Pipe Stress Analysis When Installed by Means of Horizontal Directional Drilling

Pipeline installation by means of horizontal directional drilling (HDD) is becoming a well accepted installation method globally. Large pipeline projects are ongoing, and currently steel products with diameters up to 58" are scheduled to be installed over distances up to 8500 ft. During the planning stages, an assessment will need to be made with respect to the tensile, bending and hoop stresses occurring during the pulling phase of the project. In this paper we will just focus on the installation stresses on steel pipelines. The theory and some of the conclusions can be used when considering HDPE (High Density Polyethylene) or other materials. Specific attention will be needed for the bore profile, hole diameter and jobsite setup to control and limit the installation forces and product stresses. This presentation will include an overview on the different stresses (supported by formulas) and provide tips on jobsite requirements that need to be considered during the preparation stage of a large pipeline installation. Awareness of the possibilities and limitations of large diameter steel pipe will help utility companies, engineering firms, and HDD contractors to become more successful and better prepared for future "large HDD pipeline projects".