Upper Scioto West Interceptor Sewer, Part 1

Completed in 1995 by Mole Constructors, the Upper Scioto West Interceptor Sewer, Part 1 project consisted of 4 shafts ranging in depth from 70 feet to 95 feet and approximately 9,700 linear feet of rock tunnel. The shafts were supported in the soft ground portions using liner plates and internal steel ribs. The rock portions of the shafts were excavated using conventional drill and blast methodologies and supported using rock dowels, mesh and shotcrete. The 128-inch tunnel was planned to be in rock throughout the alignment, however a buried valley was discovered approximately 1,200 linear feet into the drive. The discovery of the 300-foot-long valley required at a fifth shaft was sunk and soft ground hand mining be employed. The soft ground portion of tunnel was supported using steel liner plates and internal steel ribs. The remaining portion of the tunnel was excavated in rock through numerous water bearing solutions cavities. The rock was supported using rock dowels and channel straps. The tunnel received an 84-inch reinforced concrete pipe with Ameron (T-Lock) lining. The pipe was grouted-in-place using light weight cellular grout.