The corresponding relationship between the change of goaf pressure and the key stratum breaking

Abstract

Abstract Existing studies mostly focus on the stress change of coal in front of a goaf, but rarely conduct field monitoring on the internal pressure of a goaf, primarily due to the complex environment and other restrictive conditions of goafs. This paper first used physical simulation to monitor and analyze the internal pressure of goaf and found that goaf pressure presented a stepwise growth with the key stratum breaking. In addition, field measurements were conducted to monitor the goaf pressures of two different working faces. Goaf pressures both presented linear growth with the advance of the working face. According to comparative analysis, there were some differences between the two monitoring methods in terms of the corresponding relationship. This reflects that in the actual rock mass, after the breaking of a key stratum, the loads of the strata under its control are not transferred to the goaf instantaneously and load transfer characteristics are probably related to roof separation distribution characteristics of overlying strata, the bulking characteristics of caved rock mass, lateral stress limitation and other factors. The results of this study will offer some guidance for studies on the movement laws of overlying strata and the load transfer of overlying strata above goafs.