Black River Tunnel moves forward31 January 2012
The Lorain, Ohio, city council approved a USD 55M sewer tunnel project on 23 Jan, including a USD 53M contract for a joint venture of Walsh-Super Excavators.
The 24ft diameter (7.3m) wastewater storage tunnel will be 5,500ft (1,676m) long, and will be excavated 112 to 187ft (34 to 57m) beneath the city. The finished diameter is to be 19ft (5.8m).
According to documents submitted to the Ohio EPA this summer, an open face rock TBM will be used to mine the tunnel with some pre-excavation grouting as need. The city also noted that it “expects that the primary tunnel lining system used underneath Lorain will entail steel ribs and skeletal wood lagging (or liner plates under certain areas) to both support advancement of the TBM and support of the tunnel crown, plus any additional needed sheeting and bracing to support the floor and sides of the tunnel.”
Construction is expected to start in March and last for three years.