The Prediction of Pillar Interaction Effects for Deep Multi-Seam Workings

摘要

Mining in multi-seam workings has been undertaken for many years in the UK Remnant pillars above and/or below current working areas have an important influence on retreat gateroad conditions at five of the remaining six deep coal mines. These interaction effects need to be predicted ahead of mining so that longwall panels can be positioned to minimize roadway damage and to identify areas where additional support should be installed early into competent strata when and where it is most effective.Currently, three-dimensional elastic stress analysis using MAP3D is undertaken to predict local vertical and horizontal stress magnitudes during gateroad development and in front of the face on retreat. The predicted stress fields are often used as input to FLAC for roadway modelling.Using Maltby Colliery in South Yorkshire as a case study, this paper illustrates the MAP3D approach, together with its current limitations and uncertainties. Possible future improvements in the analysis method are proposed and the authors would welcome comments on these, or suggestions for alternative approaches.