Field Service Conditions of the Oldest Corrugated HOPE Pipe Culvert under Ohio's Roadway

摘要

A research institute at Ohio University recently conducted a comprehensive study on highway culvert structures for the Ohio Department of Transportation. During the study, a number of thermoplastic pipe structures under Ohio's highways were inspected and rated. One of the thermoplastic pipe structures was a 0.61-m-diameter (24-in.-diameter) corrugated high-density polyethylene (HDPE) pipe under State Route 145 in Noble County, Ohio. What was unique about this pipe structure was that it was the oldest thermoplastic pipe culvert in service in Ohio. The pipe was installed under a shallow cover in 1981. The Ohio University team visited the culvert site in 2004 and inspected the pipe structure thoroughly. It was inspected again in June 2010. Drainage water entering the culvert was acidic, indicating the influence of a nearby surface coal-mining operation. The pipe structure had moderate amounts of deflection under the roadway, but overall it appeared to be in satisfactory condition. In 2004, a short pipe section was taken from the outlet end to determine if the pipe material had degraded over the years from constant exposure to ultraviolet light and acid mine drainage. A series of tensile strength and density tests were performed according to industry standard test methods. Test results showed that the thermoplastic pipe material experienced little aging. Finally, a course of action was recommended for the HDPE pipe structure based on a basic risk assessment analysis.