Multi-disciplinary characterizations of the BedrettoLab – a new underground geoscience research facility

Abstract. The increased interest in subsurface development (e.g., unconventional hydrocarbon, engineered geothermal systems (EGSs), waste disposal) and the associated (triggered or induced) seismicity calls for a better understanding of hydro-seismo-mechanical coupling fractured rock masses. Being able to bridge knowledge gap between laboratory reservoir scales, controllable meso-scale situ experiments are deemed indispensable. In an effort access instrument masses hectometer size, Bedretto Underground Laboratory Geosciences Geoenergies (“BedrettoLab”) was established 2018 existing Tunnel (Ticino, Switzerland), with average overburden 1000 m. this paper, we introduce BedrettoLab, its general setting current status. Combined geological, geomechanical geophysical methods were employed hectometer-scale mass explored by several boreholes characterize conditions internal structures volume. volume features three distinct units, middle fault zone sandwiched two relatively intact units. unit appears be representative feature site, as similar repeat every hundreds meters along tunnel. lithological variations across characterization manifest complexity heterogeneity accompanied compartmentalized hydrostructures significant stress rotations. With complexity, characterized is considered characteristic that typically encountered exploration development. BedrettoLab can adequately serve test-bed allows in-depth study response crystalline