Risk of clogging

Clogging risk assessment and correlation with the properties of the soil to be excavated

The study of the adhesion requires a quantification of the natural tendency of the soil to adhere to the metal parts of the TBM (tools and metal carpentry of the excavation head) and allows the assessment of the clogging risk associated with this phenomenon. Specific studies were developed in order to evaluate the effectiveness of the conditioning agents in reducing this risk as well as the influence of other characteristic parameters.

The construction of tunnels gained a crucial importance in the development of large infrastructures and in the urban transport system in recent decades. Some phases of the excavation may become tricky when the project involves a complex historical, urban and environmental context, such as a urban area. This article, presented at the World Tunnel Congress 2019 in Naples, illustrates the results of a research activity developed at Sapienza with the collaboration of Metro C on the management of soil conditioning in mechanized excavation, one of the many delicate aspects of a project, as the Metro C line of Rome, unique in the world in terms of size, importance and complexity.

Publications on this research topic can be found here below:

World Tunnel Congress Naples 2019:

• The management of the soil conditioning process for the excavation of the Rome Metro C line

European Conference of Soil Mechanics and Geotechnical Engineering, Reykjavik 2019:

• Chemical interaction between fine-grained soil and foaming agents in tunnelling with TBM-EPB

World Tunnel Congress Bergen 2017

• Short and long term effects of chemicals on fine-grained soils