ABSTRACT
The paper describes the complex logistics and challenges to excavate the new railway of the Sarmiento line below the existing line without any disruption to the railway in operation. The Sarmiento railway with more than 300 daily trips, transporting 110 million people each year, lies entirely on surface and provides the main transport system for people moving between the western suburbs and the city center of Buenos Aires. The Earth Pressure Balance Tunnel Boring Machine (EPB TBM) chosen for the specific excavation has a diameter of 11,46m and is expected to excavate a total of 16km for the first Lot. The overall length of the three Lots adds up to 36.9Km. The geology is formed by silty clays and soft clay, silty sand and puelche (a monogranular sand with a water pressure of 2.5 bar). Along the line there are 15 huge stations excavated through conventional methodology in cavern and through top-down methodology. The main challenge of the project is to optimize production reducing the disruption for the community and stakeholders throughout the highly populated city of Buenos Aires.
