Integration of geotechnical and remote monitoring systems for the analysis and control of ground deformation in marble quarrying (Apuan Alps, Italy)

Workplace safety in quarry sites can be evaluated and established through an ac-curate monitoring of mining activities and slope stability. This last is dominantly influenced by the structural setting which, in combination with exploitation methods, affects the risk. The present paper shows the applied methodologies and the preliminary results obtained from an integrated monitoring system implemented in the Apuan Alps, within a quarry characterized by a buttress shaped remnant of previous excavation activities and accessible from 3 sides. In 1997, a rock fall event occurred in a neighbouring area of the buttress causing the interruption of quarrying activities. With the purpose of controlling the buttress stability, preserving safety conditions, planning proper remediation works and continuing exploitation activities, various monitoring systems have been installed during the years: this paper describes the 3 more recent systems that have been operating for more than one year. The instrumentation consists of geotechnical monitoring sensors composed by extensometers and crack-meters, and two topographic systems represented by a terrestrial interferometer and a robotic total station. Results from the 3 monitoring systems highlighted few critical zones whose presence was already known and precautionary measures had already been adopted; their geo-mechanical character is still under study with the aim of establishing the thresholds of risk that separate the natural rock behaviour from any probability of failure.