Estimation of serpentinite rock mass strength of Placetas - Cuba underground gold mine deposit

This study estimated the strength of the serpentinite rock mass of the underground gold mine “Oro Descanso” Placetas, Cuba. The rock mass was classified into its lithological group of massive, sheared serpentinite rocks and gabbros. The geo-technical information from the well log data obtained during drilling process (geological logs). The structural analysis was carried out through field observation and quantified by Geological Strength Index (GSI) of average values for massive serpentinite 60, sheared serpentinite 38 and gabbros 78. The generalized Hoek-Brown criterion with software programme, Rocklab 1.0, 2004 version was employed for the analysis and the determination of the rock mass local compressive strength (massive serpentinite = 1.733Mpa; sheared serpentinite = 0.464Mpa; gabbros = 10.354Mpa) and the global strength (massive serpentinite = 6.561Mpa, sheared serpentinite = 5.657Mpa and gabbros = 22.547Mpa). These estimated values characterize brittle type of failure mode and thus supports are recommended.