On August 29, 2018, the Kenny Construction/Obayashi JV crossed the finish line at the Akron Ohio Canal Interceptor Tunnel (OCIT) when its 9.26m diameter Robbins Crossover (XRE) TBM achieved breakthrough.
“One of the most challenging aspects of this job was that we launched right into the most difficult part. We had 60m of soft ground, a very short reach, and then from there we went right into a mixed face for 180m,” said David Chastka, Project Manager for the JV. “It took everybody we had in the industry, everybody from Robbins, to fight through that first 240m.”
The TBMwas designed for the project’s geology, which transitioned from soil to partial face shale to full face shale rock. The Crossover XRE included features of both EPB and Hard Rock Single Shield TBM types, with a versatile cutterhead that could be configured for hard rock or soft ground conditions. While in soft ground and mixed face conditions the machine operated in closed mode, but once it hit solid rock crews switched excavation to open mode. “The machine had the power to get to the other side and made advance rates we never thought we were going to get. It was very successful in hard rock,” said Chastka. Advance rates once in full-face shale rock reached a high of 34m in one day (two 10-hour shifts). Muck removal was achieved using a Robbins continuous conveyor, and conveyor availability remained high throughout the project.
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Now that tunnelling is complete, the machine will be disassembled and removed from its retrieval shaft this autumn. “The Ohio Canal Interceptor Tunnel is the largest public improvement project in our City’s history and a significant investment in our environment and infrastructure that will benefit Akron residents and businesses for generations to come,” said the City of Akron’s Mayor Daniel Horrigan. “Projects of this kind are inherently dangerous, and I am incredibly proud that the tunneling portion was completed without any major injuries, thanks to a dedicated team of professionals. And although Robbins is an international company with worldwide impact, we were pleased to be able to work with a local Northeast Ohio firm on this significant project.”
The OCIT Project for the City of Akron, Ohio, USA consists of the construction of a conveyance and storage tunnel system to control Combined Sewer Overflows (CSOs) for several regulators in the downtown Akron area. The EPA-mandated project includes the 1.89km conveyance and storage tunnel, as well as drop shafts, diversionstructures, consolidation sewers, and related structures.