ABSTRACT
Time today represents a new factor that must be taken in consideration when conditioning the soil during TBM mining. The longer the foam remains stable, the higher the quality of soil conditioning, the less the consumption. A new technology of readily biodegradable foaming agents represents a new way to manage the rheology of soil, ensure safety and proper extraction; these new foaming agents boast a more durable surface tension on the bubbles that ensures longer stability over time. In this way, not only the foam shall work longer but overall consumption shall be reduced when compared to conventional foams. Indeed, it is now possible to work with higher FER and lower FIR without reducing the quality of the foam and, at the same time, increase its stability over time. With this new technology, the TBM excavation cycle is optimized, contributing to the overall schedule to complete a tunnel.
