Ricerc@Sapienza

In the mechanized excavation of tunnels with Tunnel Boring Machines, an ever more frequently used technique worldwide is the Earth Pressure Balance (EPB) technology; during the excavation phases this technology requires continuous injection of chemicals under the form of foam to be mixed with the excavated soil.
Since the features of the foam influence significantly the excavation performances and the propagation of induced effects such as settlements in the environment, the studies of the parameters affecting the quality of the foam have great importance for practical purposes.

The treatment of excavation by-products has been studied using Fenton and Heterogeneous Fenton processes, by the addition of zero-valent iron nanoparticles (nZVI) as catalyzer. This study demonstrated that both methods could significantly reduce the organic content of the liquid extract from excavated soils. Operating parameters, such as pH and catalyzer/oxidant (w/w) ratio, were varied to investigate their influence on the Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD) removal efficiency.

The use of Tunnel Boring Machines (TBM) and particularly the Earth Pressure Balance (EPB) technology is one of the most commonly used way to perform mechanized tunnel excavation. The possibility to perform the excavation with high performance, avoiding risk for workers and reducing the induced subsidence, particularly important in urban area, are the main reason of the growing of this technology.

Earth Pressure Balance (EPB) technology is currently the most widely used technique in mechanized tunnelling with Tunnel Boring Machines (TBMs) and particularly in urban en-vironments, because of several advantages, as the possibility to excavate in different geo-logical conditions and effectively controlling the induced effects on the pre-existing struc-tures. EPB technology requires the continuous injection of chemicals during the advance-ment: this may induce the accumulation of xenobiotic compounds in the excavated debris.