ABSTRACT
Excavated soil (ES) produced by mechanised tunnelling (EPB-TBM) can be qualified as waste or alternatively as a by-product, depending on its characteristics and the conditions for utilisation. Tunnel excavation produces huge volumes of ES. Managing it as waste might be so expensive to dramatically impair the feasibility of major infrastructure projects. Different site-specific experimental studies were carried out on conditioning products and soil/product mixtures to assess the eco-compatibility of ES and therefore the possibility to manage them as a by-product. Firstly, laboratory tests were carried out to evaluate the less impacting conditioning products and the related dosage for an optimal soil conditioning. An environmental site-specific study was then carried out to simulate operating conditions testing different conditioned soil samples for modelling the real cases. Eco-compatibility of conditioned soil samples strictly depends on the time needed for biodegradation of conditioning agents.
The paper presents a number of significant Italian case studies.
