A 96-inch diameter, galvanized CMP culvert running under Marne Road in Fort Benning, Georgia had a severely deteriorated invert. Fort Benning knew that the culvert would need to be replaced or repaired quickly. Fort Benning sent out a bid to local contractors to identify the optimal solution. As part of the requirements, they requested a solution that would avoid road closures entirely as Marne Road was one of the major traffic routes to the base.
Robinson Paving Co. was the low bidder who submitted a reline solution that incorporated HEL-COR®, 12 GA, aluminized type 2 (ALT2) pipe to reline the existing pipe. The repair of the deteriorated structure was slightly more complicated as there were utilities on the inlet side of the road that prevented any use of equipment on that side of the road. The wetlands buffer in the affected area also limited space and use of equipment. Pulling irons were attached to a 42 LF section of pipe with a 2:1 beveled end allowing for the pipe to be pulled through the host pipe preventing any needed disturbance of the existing utilities and wetlands area. An almost 20’ deep manhole with a drop was needed on the outlet end of the road.
Due to the limited space and inability to operate large heavy equipment, a large precast manhole was not feasible or cost-effective. Contech Engineered Solutions was also able to provide a 78-inch diameter by 19.81’ tall HEL-COR® corrugated metal pipe (CMP) manhole riser with a drop inlet. An additional 23’ extension with 2:1 beveled end was attached to the manhole. A concrete bottom was poured in the bottom of the structure.
The reline took place over a two-week period. This included the reline of the host pipe as well as the additional manhole, extension, grout, backfill and seeding process. Fort Benning was very pleased with the outcome – a structural solution with an extended service life of 75+ years. The heavily trafficked Marne Road remained open throughout the entire reline process, and the existing utilities remained intact while the neighboring wetlands remained untouched.