Toledo Waterway Initiative
TWI Phase II Downtown Storage Basin
The Toledo Waterways Initiative (TWI) Program encompasses more than 45 separate projects over the course of 18 years, at a projected cost of $527 million
As part of Phase II, Turn-Key Tunneling constructed a 725-ft rib and board tunnel utilizing a hydraulically driven tunnel shield. The 12-ft diameter tunnel served as the initial pass for the two-pass tunnel system and acts as the final host for the 110-in sanitary sewer.
Turn-Key Tunneling constructed a 32-ft diameter vertical shaft for a junction chamber which served as the reception shaft for the shield removal. The tunnel was installed in lean clay with several large boulders located throughout the heading.