Abstract: In this paper, in view of the support crushing and water inrush disaster when mining under unconsolidated confined aquifer, numerical and physical simulations were used to study the influence of overburden thickness, key stratum location and structural combination characteristics, etc., on support crushing and water inrush disaster. The results show that under the remarkable load transfer faction of unconsolidated confined aquifer, support crushing and water inrush disaster is mainly related to the overburden structure. The thinner the thickness of bedrock is, and the thicker the first key stratum above coal seam is, the more easily the integral breakage of overburden occurs if the super-thick stratum exits within 10 times mining height distance above coal seam, which may easily induce support crushing and water inrush disaster in coal face. Above has been validated at No.7114 and No.7112 working faces in Qidong Coal Mine. Based on the overburden structure, the dangerous area of support crushing and water inrush can be predicted before coal mining, which may provide a basis for such disaster prevention.

Key words: unconsolidated confined aquifer, support crushing and water inrush, overburden structure, key stratum, compound breakage