Field Tests on HDPE Pipes Installed Using Horizontal Directional Drilling

The results of two field tests on instrumented high density polyethylene (HDPE) pipes installed using horizontal directional drilling (HDD) are presented in this paper. HDD is a method of installing underground pipelines that involves pulling the pipe through a horizontal borehole. HDD is increasing in popularity; however, little field research has been conducted examining the effect of this installation method on the pipe. The presented tests involved 200 mm (8 in.) diameter, standard dimension ratio (SDR) 17 HDPE pipes pulled along 55 and 90 m (180 and 295 ft) borepaths. The results include readings from a pressure transducer attached to the drill rig hydraulic system and strain gauge readings from instrumented test sections at different locations in the pipes. The presented results were recorded during the pull-back operations and for several hours after the installations were completed. The recorded strains and calculated axial strains are shown versus time and versus the approximate location in the borepath.