'Installation of Municipal Underground Infrastructure Systems Using Horizontal Directional Drilling and Ductile Iron Pipe'

摘要

Municipalities and utility owners across the nation are evaluating their water and wastewaterrninfrastructure systems and, in many cases, finding that they can relate to the old cliché of havingrna “tiger by the tail”. Not only are these entities finding that their systems are in desperate need ofrnrehabilitation, repair, and upsizing, but they are also finding a more informed general publicrnreluctant to have their neighborhoods besieged by open-cut construction. It is estimated that $83rnbillion is required today for water line replacement in the United States with expenditures of uprnto $1 trillion required to upgrade the nation’s water system over the next 20 yearsi.rnThe utilization of Horizontal Directional Drilling (HDD) for the installation of municipalrnunderground infrastructure systems is ever increasing. This paper discusses the use of HDD torninstall restrained flexible joint ductile iron pipe. It will also discuss the results of testing whichrndetermined the installation viability of various combinations of externally applied, loosernwrapped, polyethylene encasement (per ANSI/AWWA C105/A21.5) as well as special jointrnbonding for ductile iron pipe installed by horizontal directional drilling. The concludingrndiscussion addresses the increased interest in installing ductile iron pipe by HDD and will bernsupported by a recent case history.