Monitoring and expertise of microseismic activity applied to the risk management of mine-induced ground collapse phenomena on the mining concession of SOLVAY-Italy.

SOLVAY has been mining salt in Tuscany, Italy, since the early 20th century. Nowadays, SOLVAY processes solution mining in two salt mining concessions in a rather complex deposit composed of salt lenses underlying 170 m to 300 m deep. The exploitation scheme relies on a regular network of deep boreholes enabling air and clear water injection with brine extraction till the underground communication between boreholes. The brine is transported through pipeline up to the SOLVAY Marittimo chemical plant located at Rosignano.
  • Such a solution mining method periodically induces ground failures originating from the underground cavities created by the dissolution process, sometimes along with landslides. These geohazards raise a risk for the mining staff operating periodically on surface along the access tracks and working zones (drill heads, engineering structures and networks).

    To manage and prevent those geotechnical risks better, SOLVAY has entrusted Ineris, in 2015, to the operational management of the microseismic monitoring network based on the e.cenaris web infrastructure. The solution aims to yield early warning signs related to underground failures propagating upwards till the surface, relying on the routine analysis of the seismic activity. This strategy provides the best approach for the safety at work in such a mining context.