For the first time, during a field evaluation of different trenchless methods for road crossings,rncentrifugally cast fiberglass-reinforced polymer mortar (CCFRPM) pipe (Hobas) wasrnsuccessfully installed on line and at grade with horizontal directional drilling (HDD). Duringrnthis study, accuracy of installation, annular space around the pipe during and after installation,rnand effects of drilling fluids were studied. Soil displacement in the vicinity of the HDDrncutterhead, HDD reamer, and at ground surface were also monitored. Results of this fieldrnevaluation were incorporated into guidelines for horizontal bore installation developed for thernMissouri Department of Transportation's performance specifications and guidelines for piperninstallation by trenchless methods. A summary of the installation of the CCFRPM piperninstallation will be presented in this paper.rnComplete geotechnical evaluation of site soils was completed prior to boring. In the testrnembankment at the University of Missouri-Columbia's Capsule Pipeline Test Facility outsidernof Columbia, eighty feet of 24-inch diameter Hobas pipe was installed using the HDDrnArrowboreTM method. Use of this method allows the installation of larger (up to 48" diameter)rnpipe with a high degree of accuracy for following line and attaining grade. A Ditch WitchrnJetTracTM 1720 was used to make this installation. Examination of the installed pipe after thernbore was completed revealed pipe alignment that was nearly "gun-barrel straight." Pullbackrnpressures never approached the rated pullback of the machine used. The HDD operatorrnasserted after the completion of the bore that this rig could have pulled in 200 feet of Hobasrnpipe with no problem, and a larger rig like the Ditch Witch 4020 would be capable of pulling inrn300 feet of 48-inch Hobas pipe.rnThe Missouri Department of Transportation has already approved the ArrowboreTM methodrnused in maintenance and construction installations. New performance specifications have beenrnwritten to address horizontal boring under MoDOT right-of-way and for project utilityrnrelocation purposes. Centrifugally cast, fiberglass reinforced, polymer mortar pipe and its usernhave also been addressed in the materials section of these performance specifications.
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