Filling the Gaps: Pipe Re-lining Satisfies Demands for Economical, Immediate Transportation Solutions

Today, many of our nation’s highways and bridge structures show the effects of age and weathering. Precipitation, traffic flow, and the freeze/thaw process maximize this wear, forcing the replacement of structures too deteriorated to perform safely or efficiently.

Interstate 80, which runs West/East through Pennsylvania, is no exception. The interstate funds in 2004 for construction projects, including roadways, pipes, culverts, and bridges. Economical solutions to repair these components are integral in meeting the demand to complete projects. Along Section B14 in Clearfield County, engineers provided a unique, effective solution to a challenging project involving a deteriorated corrugated steel culvert pipe. The pipe, lying under 65’ of fill, was in very poor condition – completely deteriorated in specific locations. Only a 2’ high portion of the original concrete wingwalls remained, and the inlet headwall was completely removed. The original embankment around the inlet pipe was re-graded, and the stream bank had slumped into the stream. These changes caused a buildup of sediment within the pipe that impeded stream flow.

Because of the extreme fill depth, excavation or a temporary shoring system would have been required to completely remove the pipe. These options would have required an exorbitant amount of funding, disrupted traffic, and affected area businesses. Tunneling was also considered; but again, this solution proved economically infeasible. Weighing cost and hydraulics with environmental impact and service life, structural engineers chose the method of re-lining. The pipe, originally 72” in diameter, received a 60” inside diameter, .138” thick aluminized steel spiral rib lining system with a concrete paved invert. The new lining carried the complete weight of fill, while the lining chosen minimized the increase in headwaters that would make a heavy impact on flooding upstream.

Piping was placed efficiently without environmental disturbance. During construction, a staging area was required for placement of the pipes. Each pipe section had external skids that aided in its placement. As placement progressed, grout was placed in the spaces between the new and existing pipe using injection ports in several lifts so the pipe didn’t become buoyant. During the re-lining, stream flow ran through the pipe normally and was pumped through pipes during grouting and installation of the invert. With the new pipe in place, the service life of the pipe was extended to over 80 years, and the project, from design to completion, took only 1.5 years.

As the future of transportation becomes the present, engineers must persist striving for economical designs that satisfy a growing, demanding infrastructure. As just one of those solutions, pipe re-lining will continue to meet these requirements.