Overlying strata fracture structure and stability control technology for ultra large mining height working face

According to the surrounding rock stability control problems of ultra large mining height working face from super-large space and strong perturbation of r ock formation, the roof damage stress path effect of ultra large mining height working face was analyzed by theoretical analysis and numerical modeling method based on the mining practice of Jinjitan Mine with 8 m ultra large mining height working face. The“cantilever beam + voussoir beam"fracture structure of roof and surrounding r ock stability control technology were put forward for ultra large mining height working face. The mine ground pressure was measured and analysis for ultra large mining height working face. The results showed that the peak stress, differential stress and strength-stress ratio of sandstone in different horizons had very great difference, w hich influenced the roof fracture state and fracture structure form directly. The roof strata were easily form“cantilever beam + voussoir beam' fracture structure of 8 m la rge mining height working face in Jinjitan Mine. Through developing ZY21000/38/82 D hydraulic support, improving the strength of hydraulic and the composite stiffness between hydraulic support and rock, the safety, eficiency and high exploitation rate were realized in 8 m large mining height working face of Jinjitan Mine.