Ceremony marks Terratec TBMs Buenos Aires start

26 June 2020

Assembly has started in Buenos Aires on the first of two 4.66m-diameter Terratec EPB TBMs that will bore the Argentine capital’s Rio Subterraneo a Lomas tunnel. The 13km-long tunnel will form a key part of the multi-billion dollar Agua Sur water infrastructure project - the country’s largest such undertaking in 40 years - and provide fresh water for 2.5 million people in the Southeast Buenos Aires metropolitan district.

The start of the project was marked by a cutterhead lowering ceremony in the presence of Argentine president Albert Fernandez, other government officials and national water company AySA.

The two machines will be used by CMC di Ravenna to excavate through variable soft ground geology, ranging from silts to sandy silts with some cobbles expected. Mining at an average 25m depth, the TBMs will install precast concrete rings comprising segments 250mm thick and 1,400mm wide in a four-plus-two (key) configuration.

Terratec said the TBM’s high-torque, soft-ground cutterheads have a spoke-style design with a 49% opening ratio. Cutting tools comprise fixed and back-loading knife bits that help ensure rapid advancement and minimum interventions.