ABSTRACT

The management of the spoil from0 a high-speed railway tunnel to be constructed with EPB technology required the geotechnical characterization of the conditioned soil after excavation. This paper describes the laboratory characterization before and after chemical conditioning of the two lithotypes that should be encountered more extensively by the EPB-TBM. The influence of chemicals on the geotechnical properties was investigated by simulating the conditions that muck will experience during its temporary stock on site (“ageing”), to meet environmental and geotechnical requirements for its re-use. The evolution of the index properties, the compactability and the shear strength was followed with measurements at 0, 7, 14 and 28 days (end of ageing) after the injection. In Author’s knowledge this experimentation was the first attempt in Italy to characterize a chemically conditioned spoil at such extent.