Mechanism of Overlying Strata Structure Instability during Mining below Unconsolidated Confined Aquifer and Disaster Prevention

There is a layer of the unconsolidated confined aquifer (UCA) made non-cemented sand and grit on bed Quaternary thick topsoil in many coal mines east north China. Existing bedrock measures, it poses serious threat to mine safety. Worse, caused supports crushing water inrush disasters (SCWIDs) resulted significant economic losses. Aiming at above problems, this paper adopts simulation experiment, field measurement, engineering detection, theoretical analysis conduct research. The research reveals overburden’s destructive rules during mining under UCA. results indicate that UCA plays an important role process load transfer due its mobility replenishment time. When close aquifer, leads overburden breaking entirely sliding instability bond-beam structure, then, flowing fractured zone develops rapidly connects which fundamental reason for SCWID Based mechanism SCWID, prediction method support hazard zones was put forward. Artificial pre-split blasting based location key stratum applied prevent SCWID. proposed methods have been used 7131 working face safe achieved.