Concrete Pipe Aids Storm Water Conveyance Tunnel

Aug. 25, 2014

The Miller Park to Pershing Sewer Separation Project included approximately 2,300 ft of 60-in.-diameter concrete pipe for storm water conveyance in the Miller Park area of Omaha, Neb. About 1,300 ft of the sewer were completed utilizing tunnelling methods. The project removed storm water flows from a combined sewer, thereby reducing the potential for upstream flooding, local rain-induced basement backups and the combined sewer overflow volume at a combined sewer outfall. Specially designed reinforced concrete pipe was the only product considered for the tunnel, which was completed in October 2013.

The pipe was designed and produced by American Concrete Products Co. with a double O-ring gasket and a steel bell joint to take advantage of as much wall thickness as possible for the jacking surface. This allowed jacking forces to increase while minimizing the number of intermediate jacking stations. Test ports were placed between the gaskets to facilitate the testing of the joints prior to pushing and post installation. Tests were performed
after the initial set. The concrete mix was designed to allow stripping of the forms six hours after casting, and
to achieve high-early-strength concrete (6,000 psi) within seven days. The pipe was produced in
8-ft lay sections for the construction of the pipeline.

Pipe production started in May 2013 by double-pouring two forms to produce four sections per day with two Dayton Superior7 utility anchors cast in for handling the pipe. Graham Construction U.S. was
the general contractor, and NADA Pacific Corp. was the microtunnelling contractor.

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