Influence of ultra-thick hard stratum migration on advance abutment pressure of working face
In order to reveal the influence of the ultra-thick hard stratum migration on the evolution law and variation features of the advance abutment pressure of working face,taking the occurrence of typical ultra-thick hard stratum of Yangliu Coal Mine as the model,by means of physical simulation and mechanical simulation,the model is compared with the model with no ultra-thick hard stratum in overlying strata.According to the research,the influence of ultra-thick hard stratum on the advance abutment pressure of working face mainly concentrates in the stage before the breaking of the ultra-thick hard stratum,with high stress concentration,wide impact range,and severe impact.When the stratum is about to break,for the working face with ultra-thick hard stratum in the overlying strata,the peak value and influence range of the front abutment pressure are 1.15 and 1.9 times of those without that kind of stratum.When the stratum is stable or broken,for the working face with ultra-thick hard stratum,peak value of the advance abutment pressure and the influence range are relatively small compared with those without that kind of stratum,the influence on the working face is relatively weak.The increase of the peak value of the advance abutment pressure will inevitably lead to an increase of the influence area of the coal wall ahead of the working face.
ultra-thick hard stratumadvance abutment pressureevolution lawmechanical simulation experimental methodsvariation features
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