Safety in underground quarries and cavities

The considerable number of abandoned quarries and underground cavities in mainland France, estimated at around 500,000, exposes municipalities to the risk of ground movement. Cavities are either natural, caused by the dissolution of rock underground, or man-made, formed as a result of rock extraction or the excavation of underground structures.
Their location, which is not always known, poses problems for land use planning in urbanised or urbanisable areas. In addition, nearly 3,600 quarries (underground and open-pit) are in operation in France. The safety of their operation is a challenge both for the public authorities responsible for regulatory developments and site monitoring and for the operators themselves.
The Institute has comprehensive expertise that enables it to provide operational solutions to the problems posed by cavities (geotechnics, ventilation and dust management, environmental monitoring). 

Roadmap for risk prevention for underground cavities

At the instigation of the Ministry for Ecological Transition and Territorial Cohesion, the Institute has developed a roadmap for risk prevention for underground cavities in collaboration with BRGM, Cerema and IGN. INERIS guides and coordinates the work carried out within this framework and incorporates its own activities into it. 

Improving hazard knowledge for assessing risks associated with cavities and rock faces in response to land use planning challenges

The Institute's support for public policy aims to better quantify and prevent hazards related to cavities and to help promote and regulate the development of exposed sites and territories in order to assist the State, local authorities and project owners involved in their management. In particular, INERIS evaluates and disseminates management and prevention methodologies and tools and develops cavity inspection and monitoring capabilities (e.cenaris monitoring data management platform). 
The Institute also conducts "real-life" awareness-raising activities with the DDTs and DREALs at its platform in Saint-Maximin (Oise), which is located in an underground quarry. 
To improve understanding of hazardous phenomena related to cavities and quarries, INERIS is conducting research to monitor and predict the risk of rock mass failure or instability and underground structures. Its experts are developing digital modelling tools and specific behavioural laws to explain cavity failure. 
To maintain contact with the field, INERIS teams provide ongoing expertise and advice to local authorities, project owners and companies in the extractive industries. In addition to regulatory studies (PPRN4 , DDAE5), this includes underground geotechnical inspections and diagnostics, hazard assessment and mapping, the definition of safety principles and project management assistance for their implementation; operational monitoring and measurement and characterisation of environmental or health impacts (vibrations, dust, pollution) and feasibility studies for underground public access buildings (ERP).