Alternative Construction Methods and Pipe Material Provide Solutions for Cleveland WWTP Project

摘要

The Easterly Wastewater Treatment Plant (WWTP), located on the northeast side of Cleveland between Lakeshore Boulevard and Lake Erie, provides wastewater treatment services for 334,000 residents and various businesses in northeastern Cleveland and the surrounding suburbs. In addition to treating wastewater from homes and businesses, the Easterly WWTP also receives and treats stormwater from combined sewers. Over 94 million gallons of wastewater per day (mgd) are treated at the Easterly WWTP. The Northeast Ohio Regional Sewer District (NEORSD) awarded the contract to Shook Walbridge Joint Venture. The Sustained Secondary Improvements Project includes expanding the Easterly Wastewater Treatment Plant's 330 MGD capacity to 400 MGD. The project included improvements to the plant's existing aeration tanks and final settling tanks, construction of six additional final settling tanks, improve hydraulics to support the capacity increase, and implement various miscellaneous improvements. More specifically, as part of the improvements, the project required auger-cast-piles to support new structure foundations, but also to support pipe cradles for the final effluent piping. These piles were part of the original design to support the 60", 72" and 84" diameter effluent pipe, which was designed with Prestressed Cylinder Concrete Pipe (PCCP). As a way to solve some constructability issues, Shook-Walbridge proposed a pipe material and pipe foundation substitution in lieu of the PCCP pipe and auger-cast-piles. Their substitution included the use for large diameter fiberglass pipe along with a continuous concrete ballast slab to address floatation concerns. As part of the substitution review process, various aspects of the alternative installation method had to be reviewed prior to acceptance of this alternative. This paper will review the different key components considered during the substitution review process.