Study the variations of sinkhole depth with respect to working height in underground coal mines

摘要

Minerals extraction from underground mine may lead to the disturbance in equilibrium of the overlying strata and these disturbances reflect in the form of subsidence on the surface. Subsidence is of two types, trough and sinkhole subsidence. Sinkhole subsidence is an abrupt local depression at the surface due to underground excavation which can be hazardous to life and property due to its tendency to occur without admonition. Sinkholes occur due to the failure of a mine roof which migrates through the overlying strata until the failure zone intercepts the unconsolidated overburden. It is generally assumed that the depth of sinkhole subsidence occurs is same as the working height but in field investigations it was observed that this implication is not withstanding on the actual working and needs detailed analysis work. Considering this study, authors presented detailed analysis of field investigations which occurred in some of the coal mines of South Eastern Coalfields Limited (SECL) in this paper.