Assessment of Emerging Pulled-in-Place Pipe Products for Trenchless Applications

Pulled-in-place pipes for trenchless construction applications have traditionally consisted of Steel and High Density Polyethylene (HDPE) material. While providing excellent documented results, these two materials require professional welding and fusion of their joints prior to installation. New developments have introduced two emerging pipe products that are rapidly gaining acceptance as alternatives to Steel and HDPE. These are Flex-Ring Restrained Joint Ductile Iron and C-900 Polyvinylcholoride (PVC) pipes. Centrifugally cast for transport of water, sewer, or other liquids, the Flex-Ring Ductile Iron pipe allows for up to 5 degree flexing and comes in diameters ranging from 100 mm (4 in.) to 900 mm (36 in.). Additionally, the boltless restrained connection provides flexibility, ease of assembly, and positive restraint against endwise separation due to pulling during trenchless installation. The restrained joint C-900 PVC pipe increases the tensile capacity of a standard bell-and-spigot PVC pipe by 35 times, while maintaining the ability to negotiate tight curves (i.e. min. bending radius of 19 m). Typically used in horizontal directional drilling and pipe bursting installations, both pipe products meet AWWA pressure standards making them suitable for pressure pipe applications. This paper provides discussion on these two emerging pulled-in-place products for trenchless applications and analysis of testing results supplemented with supporting field case studies.