Layout design for interactive zones in longwall multiple seam mining
Appalachia requires design guidelines for the increasingly popular multi-seam longwall method. Entry layouts often depart from the ideal when finally developed. The thesis examines the occurrence of ground control problems, and possibilities for improvements in strata control, in a variety of undermining situations. The effects of upper seam loading on undermining operations are invest~gated using physical modelling. Photoelastic stress analysis is used as a powerful research tool to analyze complex multiple seam entry systems. Yield pillar use is also examined, in anticipation of their widespread application for ground control. Case examples support the research findings, and specific conclusions aim to assist layout design in interactive zones.