DBPapers
DOI: 10.5593/SGEM2014/B12/S2.076

MICRO-TO-MACRO SCALE GEOMECHANICAL CHARACTERISATION OF FAULT ROCKS

P. Gattinoni, L. Scesi, S. Scorciolla
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-08-7 / ISSN 1314-2704, June 19-25, 2014, Book 1, Vol. 2, 597-604 pp

ABSTRACT
The goal of this study is to obtain a complete full-scale characterization of rock faults involved in the excavation works of the Brenner Base Tunnel, which crosses one of the main tectonic alignments of the alpine area, the Periadriatic fault. The characterization was carried out at different scale, from macro (through drillings and geomechanical surveys) to meso (lab tests on specimens) and micro-scale (through thin sections), in order to find a correlation between the different scales properties of the rocks. Finally, a relation between the voids ratio at the micro-scale and the fault rocks conditions at the macro-scale was pointed out by mean of the Geological Strength Index. As a result, using micro-scale properties, whose cost is much lower than the cost of geotechnical tests, good estimation of the fault rock strength was achieved, avoiding quite typical overestimation arising from the use of literature values.

Keywords: Brenner Base Tunnel, compressive strength, fault rocks, geomechanical classification, Italy, thin section.