Three dimensional geotechnical modelling of abandoned bord and pillar workings

The paper reviews the results of investigations of the Borehole Seam with reference to the available historical data. The results show that the method of working and the height of the working section in some areas vary significantly from that reported in the 1908 Royal Commission on Earth Subsidence at Newcastle. Pillar stability analysis indicates a significant difference in the factor of safety (FoS) in areas of known instability and those where the workings have remained stable.