A physical and numerical investigation of sudden massive roof collapse during longwall coal retreat mining

One of the most challenging safety problems in underground longwall coal mining is massive roof collapse in mined-out area during retreat mining. Understanding the mechanisms and geotechnical precursors of massive roof collapse is of great importance for risk assessment and ground control. In this study, a large-scale physical model was created based on a real case to simulate massive roof collapse during longwall coal retreating mining. A good...