Agua Sur TBMs ready
2 November 2018Argentina – Two Terratec TBMs bound for the Río Subterráneo a Lomas tunnel have undergone factory acceptance. The 13.5km tunnel will form part of the Agua Sur potable water supply system.
Contractor CMC di Ravenna will navigate the variable soft ground geology along the project alignment, which ranges from silts to sandy silts with some cobbles expected.
The TBMs are 4.66m-diameter EPBMs with a spoke cutterhead design with a 49% opening ratio. Tools are fixed and back-loading knife bits.
The tunnel will be excavated at an average depth of 25m, beginning with an approximately 400m radius curve and continuing along an essentially straight alignment, reaching a maximum slope of +/- 2.0%. As the machine progresses, it will install a precast concrete segmental lining ring consisting of six (four parallelograms and two keys) 250mm thick, 1400mm wide, segments.
