Unique calibration case study for predictive model of installation loads for directional drilled fusible PVC pipe

The nature of the horizontal directional drilling (HDD) process necessitates the use of pipe products that are capable of being pulled into final alignment via a tensile force, as opposed to being pushed or jacked by segmental means. While steel and high density polyethylene pipes have been historically used with HDD methodology, a fusible polyvinylchloride pipe (FPVCP) product has been one relatively recent addition to the materials available for the installation of water, wastewater, pressure, and nonpressure infrastructure. Maximum safe pull load criteria have been developed for this material, and recent research was focused on aligning current predictive pull force modeling with this material for use in HDD application. Recent work has presented the predictive model and general validation of its use with FPVCP. One particular set of monitored HDD installations that was gathered during the field validation stage of the research provided unique insight into the use of the predictive model to calculate the required pulling force for use in HDD installation methodology. An overview of the model background, field validation study, and specific case study will be reviewed. Specific conclusions regarding this case study relate to the importance of drilling fluid accuracy in the model.