Rock mass behavior in deep mines: in situ monitoring and numerical modelling

Overview & Synopsis

With the aim of better understanding the mechanical behavior of rocks solicited by underground excavations, the rock mass response to mining was studied based on a comprehensive approach. For this purpose, a deep area of the metal mine of Garpenberg (Sweden) was instrumented with a geophysical and geotechnical monitoring network. In situ monitoring data were analyzed and interpreted considering the specific mining method and the local geological setting. In addition, an advanced 3D elasto-plastic numerical model of the mine was built to better understand the interactions between quasi-static stress changes due to mining and the generation of the induced seismicity. Results show a complex rock mass response, strongly influenced by mining and geological characteristics, both in term of seismic and aseismic phenomena. The case study of Garpenberg also highlights the strong potentiality of the proposed approach, which can help improving the seismic hazard assessment in deep mining operations.