of;
Energy;
Science;
and;
Engineering,;
Henan;
Polytechnic;
University,;
fiaozuo;
454000,;
China;
Department,;
Hebi;
Coal;
Co.,;
Ltd.,;
Henan;
Coal-lndustry;
and;
Chemical;
Group;
Co.,;
Ltd.,;
Hebi;
458000,;
China;
稳定性分析; 放顶煤开采; 围岩稳定性; 煤层开采; 急倾斜煤层; 顶板运动; 负载系数; 应力集中区;