Pillarburst proneness due to large-scale excavations in deep mines (Case study: The Provence coal mine)

S. Ahmed (1) , Marwan Al Heib (2) , Yann Gunzburger (3) , Vincent Renaud (2)

1 Cairo University
2 INERIS - Institut National de l'Environnement Industriel et des Risques
3 ENSMN - Ecole Nationale Supérieure des Mines de Nancy

The objective of this paper is to examine the applicability of the rockburst proneness criteria by using the numerical modeling tool. Many rockburst criteria are illustrated by the case of a deep coal mine in France, in which pillarburst (RC2) took place in 1993 in the shaft station, which is located at 1000 m from the earth’s surface and it was excavated in 1984 by using the room-andpillar mining method. The shaft station is surrounded by several longwall panels that were exploited between 1984 and 1994. To assess the stress redistribution and the stored strain energy concentration due to mining operations, a detailed large-scale finite difference numerical model of the mine has been constructed. The excavations in the numerical model are performed into two steps. Firstly, the shaft station galleries’ are excavated to determine their effect on the bursted pillar (RC2). Then, the longwall panels are excavated year by year to detect their effect on the shaft station pillars’. The numerical modeling results show that the vertical stress increased on the pillars due to the excavation of the longwall panels. To assess the pillarburst proneness in the shaft station area, the energy-based rockburst criteria (i.e., Loading System Stiffness (LSS)) are found to be more efficient than the stress-based rockburst criteria (i.e., Brittleness coefficient (B)).

Domaines: Sciences de la Terre

S. Ahmed, Marwan Al Heib, Yann Gunzburger, Vincent Renaud. Pillarburst proneness due to large-scale excavations in deep mines (Case study: The Provence coal mine). 53. US Rock Mechanics / Geomechanics Symposium, Jun 2019, New York, United States. ⟨ineris-03237759⟩