Research on mining stress distribution law of overburden under typical key strata structure

Most researches on coal-seam abutment pressure are carried out based on homogenizing overburden structure of working face at present, while influence of internal structure of the overburden is not fully considered. For the above problems, based on key strata theory of ground control, mining stress distribution law of overburden under typical key strata structure was researched using numerical simulation through changing location and thickness of key strata. The research results show that with distance increase between key strata and coal-seam, advance abutment pressure peak value in working face decreases gradually, the peak value in soft rock under key strata decreases firstly then becomes stable, the peak value in soft rock over key strata increases firstly then becomes stable, and range of stress concentration area decreases. With increase of key strata thickness, the peak value in working face increases firstly then becomes stable, the peak value in overburden increases gradually, and range of stress concentration area increases.