The Gulfport-Biloxi International Airport in Gulfport, Miss., was undertaking an airport improvement project that included repairing, repaving, and adding new runways and taxiways. As part of this improvement project, the airport discovered several aging and deteriorating drainage culverts under the existing runways and taxiways. The old reinforced concrete pipe (RCP) culverts were starting to separate, so the airport decided this was the best time to repair them since the improvement project was already ongoing. Initially, the airport decided to fix two RCP culverts. One culvert was 950 ft long and had a 54-in. diameter, and the other measured 550 ft long with a 48-in. diameter.
The airport decided to reline the 54-in. and 48-in. RCP culverts instead of replacing them. The engineering company on the project, Neel-Schaffer Inc., gave the main contractor, Hosea O’Weaver & Sons, an option to use either the Snap-Tite culvert-lining system or “cured-in-place” pipe for the pipe repair. Snap-Tite pipe was more cost-effective and safe, and easy to install.
The high-density polyethylene (HDPE) Snap-Tite pipe system has a patented male/female machining at each pipe section end. During installation, the machined sections are ‘snapped’ together, piece-by-piece, and pushed into the full length of an existing pipe. Any annular space and voids between the old culvert and new liner are filled in with grout. The pipe liner is available in lengths from 2 ft to 50 ft, and is available for culverts with diameters from 8 in. to 84 in. Snap-Tite also meets American Association of State Highway and Transportation Officials (AASHTO) Standard M326 for rehabilitating culverts.
The airport, engineer and contractor worked with Ryan Harrington, Snap-Tite representative, to choose the right size and length of Snap-Tite pipe for this project. Snap-Tite supplied a 48-in. Snap-Tite pipe for the 54-in. RCP, and a 42-in. Snap-Tite pipe for the 48-in. RCP. The Snap-Tite pipe arrived on site in 49-ft sections, ready for joining and installation.
Hosea O’Weaver & Sons hired sub-contractor Cambridgemoen LLC to handle the Snap-Tite culvert-lining portion of the project, which was one part of the larger five-phase runway/taxiway improvement. A benefit of relining the culverts with Snap-Tite, as opposed to replacing them, was that resurfacing runways and taxiways takes place alongside the culvert rehab without any disruption to the surface of the runways and taxiways. More importantly, an airport is still able to use the runways and taxiways for plane traffic while the relining takes place.
The pipe-relining phase of the project took less than a week to complete. For each of the culverts, the sub-contractor slid one of the Snap-Tite pipe sections inside the RCP and then snapped a second section to it using only come-a-longs and chains. This was done with each section until the pipe liner was fully in place inside the old RCP. Once the RCP was lined, the Cambridgemoen crew filled in any annular space between the RCP and Snap-Tite pipe with grout. Though the Snap-Tite pipe is a smaller diameter than the original RCP, the drainage flow is maintained due to Snap-Tite’s smooth wall interior. In many cases, Snap-Tite even improves the flow through the culvert.
“The installation of Snap-Tite was without problems, and to date, the pipes have been functioning correctly,” said Susana Cook, Neel-Shaffer engineer. “We are planning on using Snap-Tite in future drainage improvements for this airport, and for other airports with similar needs.”