A time dependency prediction of the number of mining subsidence events over a large mining field with uncertainties considerations

International audienceOre and mineral extraction via underground mining may induce ground subsidence. Depending on the technique used for excavation, subsidence may be intentional and occur during the extraction or accidental and occur long after the end of mining. This latter case holds for room and pillar mines that were assumed stable at the end of mining but then develop instabilities over the long term. Many regions exists where a large number of mines were excavated and are now abandoned. This is the case in France with the iron-ore field that displays more than 500 abandoned mines over a surface of 140 km2. Mining subsidence can be considered a hazard that leads to ground movement and may damage buildings and the time prediction of subsidence is a key point for risk analysis studies. Prediction may concern a specific mine: What is the probability of collapse of a given mine in the next decade?, or a whole region: What is the probability of observing a given number of subsidences in the next decade ? This second question is investigated in this study..