by the U.S. Army Corps of Engineers for storm drainage applications. The pipe has an extended, reinforced bell with a polymer composite band and gaskets that add an additional factor of safety within each joint. The joint performance meets or exceeds the 10.8 psi laboratory performance standards per ASTM D3212 requirements. The ADS plant in Bessemer City, NC manufactured the pipe. The company has a network of 63 strategically located local plants and 32 distribution centers. The terminal’s storm drain system, designed for a ten-year storm, needs to carry runoff for more than a mile with minimum slope of 0.33 percent to the containment pond. It also had to be able to withstand live and dead loads that would be greater than an average highway project as a loader container handler is rated at nearly 92,000 pounds per axle as well as other heavy equipment typically found at a con- tainer terminal. Specific minimum cover was determined in order to compensate for flotation due to the high groundwater level as well as the live and dead loads that would be present on the site. “The design loading calculations were for vehicles that aren’t typically what you’d use on a standard highway job or site job,” Timmons said. “We had vehicles that would be used at the terminal with design loads beyond anything I had worked with on previous projects. The empty container handlers along with the Bombcarts produced some of the larger loads on the pavements and were used to ensure sufficient cover was provided for the storm drain pipes. There was a lot of coordina- tion with ADS engineers on the appropriate design load to use, and we proceeded with the ADS spec for railway applications.” “Basically, the whole site is marsh area and filled in with stone” ex- plained Billy Fulton, utility manager for Banks. “It’s a marsh area that has the ability to settle so we had to find something that would be flexible and obviously concrete pipe wouldn’t be able to handle that –when the soil would settle the joints would come apart. So, when they looked at using an alternate pipe, basically the polypropylene pipe was one that met the criteria of what they were looking for, which was the structural stability of the pipe and the longevity of the drainage system. We had a lot of water to contend with because we’re in the low country here, and the water’s often below sea level near the river. Using pumps, we got the water under control, put the polypropylene 60-inch pipe in and started rolling from there. We started out at 15 feet deep, and the shallowest we got was about five feet, then back filled it in equal amounts around the pipe. And it’s standing up well.” Geosynthetic fabric was used over the pipe bedding and run up the sides of the trench to help deal with the overall settlement of the site. This will also help to prevent migration of fines from the ballast stone and screened materials. Geogrid was used to provide support to coun- ter differential settlement. “If we were getting into the softer, silty material,” Timmons offered, “we placed geogrid underneath the pipe to reinforce the soil condi- tions a little bit and limit the amount of settlement that would occur underneath the pipe. Using geogrid as a sub-bed under the pipe and also underneath the stormwater boxes improved the trench conditions of the pipe before we backfilled with the on-site stone.”
of the redesign, some 27,000 feet of ADS HP Storm pipe in diameters ranging from 12 to 60 inches in diameter was used to convey all storm water on the 280-plus acre site. Distributor, Ferguson Waterworks, handled the logistics of providing the pipe, fittings, and other required components on a just-in-time basis. Due to its size and the solution for the complex situation, the under- taking was named Project of the Year for the Drainage Division of the Plastics Pipe Institute, Inc. (PPI), the major North American trade association representing all segments of the plastic pipe industry. The association’s annual awards program recognizes projects and members for exceptional contributions to the industry. Submissions in the as- sociation’s divisions are reviewed, evaluated, and voted upon by the PPI members. “The use of polypropylene pipe at the new terminal shows the ben- efits of plastic pipe over traditional materials,” stated David Fink, president of PPI when he presented his association’s award to ADS. “This project is the premier privately funded project in the State of South Carolina. It demonstrates to every contractor and engineer about the benefits of plastic pipe can provide for their jobs especially DOT roadway construction projects. ADS HP STORM has exceeded the expectations for installation, durability and schedule.” Rapid completion of each portion of the project was critical because a delay on one part would cause a rippling effect of delays all through the site. Using ADS HP STORM pipe enabled Banks Construction Company (North Charleston, SC) to stay on the aggressive construc- tion schedule by saving months of install time verses the time and man- power that would have been needed for concrete box culverts and pipe. “Banks estimated that HP STORM pipe could be installed twice as fast as conventional concrete drainage products,” reported Daniel Currence, P.E., director of engineering for the Drainage Division of PPI. “In fact, using two, seven-man crews, they reported averaging 160 feet a day of 60-inch diameter pipe, and nearly 300 feet a day for 18 to 30-inch diameter pipe for example. This is a high-performance polypropylene pipe for gravity-flow storm drainage applications that couples polypropylene resin technology with a dual-wall profile design for superior performance and durability. The smooth interior wall of- fers additional strength as well as a high rate of water flow.” The HP Storm polypropylene pipe meets ASTM F2736, ASTM F2881, andAASHTOM330 for the respective diameters and is approved for use
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december 2020
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