Abstract: Aiming at the phenomenon of strong underground pressure and abnormal pressure law in fully mechanized caving mining face under gully landforms, the paper takes the advancing process of a mine 12309 working face through gully landforms as the engineering background, and comprehensively uses numerical simulation and similar simulation research method, analyzed the overlying strata migration and fracture characteristics and the evolution of plastic zone during the advancement of the working face, and revealed the influence mechanism of gully landform on the behavior of fully mechanized caving mining. The research results show that the breaking of the main key stratum will cause the separation between the bedrock and the loess stratum, causing the crack to penetrate to the surface and form a crack. At this time, the uneven surface load of the gully landform is likely to interact with the mining stress, causing the upslope section of the overburden and loess stratum has a tendency to turn to the goaf, resulting in abnormally violent underground pressure in the fully mechanized caving face; Simultaneously, similar simulation results quantify that the first weighting interval of the basic roof of 12309 working face is 35 m, and the periodic weighting step distance is between 23 and 34 m. Numerical simulation analyzes the evolution of the plastic zone of the overlying strata in the working face, which is consistent with similar simulation results. This research conclusion can provide a reference for advancement planning of working face under similar conditions.

Key words: gully landform, main key strata, overburden failure characteristics, simulation