A groundbreaking ceremony has been held to mark the start of construction on the $113M Chattahoochee tunnel in Georgia, US.

Contractor Gilbert/Healy JV will construct the 16.3km long, 5.3m id tunnel, using two TBMs at depths between 39.5m and 115m. Design is by Jordan Jones & Goulding. The contract also includes construction of two 9.9m diameter construction access shafts, four connection shafts to the existing interceptor sewers and a 36m diameter pump station shaft.

Initially, the JV will excavate new shafts for the pump station at R L Sutton and the two construction shafts, one at Elizabeth Lane and one at Circle 75.

Drill and blast will be used for sinking the access shafts that will be used for installing the TBMs and spoil removal. An estimated 642,105m³ of rock weighing 1,150,000t will be excavated during construction that is scheduled to last 44 months.

The system has been designed for the client, Cobb County Water Systems, to realise federal government standards of wastewater discharge.

Related Files
Cross section of the tunnel line in Georgia