ABSTRACT
Rapid geotechnical characterisation of excavated materials is key to all initiatives aimed at mitigating the impacts of managing the materials excavated during tunnelling in particular by maximizing reuse and re-employement by immediately sorting materials of good geotechnical quality (applications for concrete, subgrade layer…). Rapid characterisation is a materials identification process during the work site phase that is essential given the pace of the tunnel boring machines and the need for significant temporary storage areas pending analysis results. This characterisation can only be performed after geological investigations (soundings, exploration galleries) enabling geological formations of good geotechnical quality to be selected and on which rapid characterisation will be performed. It is not sufficient in itself and requires more advanced tests after the materials have been sorted (L.A./M.D. tests. grain-size characterisation, V.B.E.). At present, contracting authorities, project managers and companies are looking for rapid tests that are fast and easy to put in place on the site. This article gives food for thought for future research by presenting resistance test results carried out on good geotechnical quality materials on the T.E.L.T. site and the correlations between the Point Load Test (Franklin test) and the Los Angeles test on untreated materials and the dynamic fragmentation test and the Los Angeles test on screened materials.
