Analysis for Long-Term Response of Pipes Installed Using Horizontal Directional Drilling

Abstract

Estimation of the pulling forces during installation is an important step in the successful design of a horizontal directional drilling project. Moreover, estimation of the postinstallation loads is important for the prediction of the long-term performance of the installed pipe. An algorithm is developed to calculate the short and long-term response of steel (elastic) and polymeric (viscoelastic and viscoplastic) pipes installed using horizontal directional drilling. The program simulates the movement of the pulling head, calculates the installation loads, and employs nonlinear, time-dependent constitutive models to calculate the polyethylene pipe response. The program is evaluated by comparing its calculations with known solutions, as well as with other commonly used load estimation methods. After evaluation, the analysis is used to analyze a typical horizontal directional drilling installation. It is shown that the pipe experiences cyclic response during installation and a combination of creep and stress relaxation in the long-term.