This tunnel is part of Akron’s Northside Project to improve the City’s sewer infrastructure. Located along the Cuyahoga River, the entire tunnel is designed to collect and store over 10 million gallons of combined sewer overflows. Challenges of the site conditions included extreme weather and proximity to the river that necessitated strict environmental compliance.

Drill Tech Drilling & Shoring, Inc. successfully completed excavation of three separate tunnels on the Northside Interceptor Tunnel Project under contract with Granite Construction Company. Drill Tech utilized a new Sandvik roadheader, model number MH 621 to excavate the three tunnels.

The Tunnel Overflow Conduit (TOC) consisted of a tunnel excavated from a launch portal to the Tunnel Diversion Structure (TDS) Shaft. The overall length of tunnel was 370 linear feet with excavated dimensions of 23.5′ high by 22.5′ wide (horseshoe). Tunnel support consisted of rock dowels, wire mesh, and shotcrete.

Once at the TDS Shaft, the roadheader was used to excavate a second TBM assembly chamber tunnel. This tunnel had an overall length of 350 linear feet with excavated dimensions and tunnel support similar to the TOC. After completion of the TBM assembly chamber, the roadheader was repositioned within the TDS shaft to excavate a third tunnel identified as Rack 32.