Research on roof caving mechanism and influencing factors in inclined ore body caving mining

Abstract

In the process of caving mining, the overlying strata often fall down to form a concealed goaf. The goaf of caving method is characterized by strong concealment, complex shape and unstable roof. The mathematical model of energy dissipation structure of goaf instability and caving is constructed, and the mechanism of goaf instability and caving is revealed from the perspective of energy. By establishing the joint coupling model of inclined ore bodies in metal mines, the development mechanism and influencing factors of roof caving arch along dip and strike are studied. The research shows that the roof surrounding rock of goaf has the characteristics of double arch of “stress - caving” when mining with inclined ore body caving method; The falling arch is basically symmetrical arch along the strike and asymmetrical arch along the dip, which is higher in the middle and upper part of the dip and lower in the lower part; The relationship between the maximum displacement of caving and the thickness of ore body is quadratic polynomial; The lower the dip angle of the ore body is, the larger the roof caving range is, but the smaller the maximum caving displacement is; The existence of hanging wall fault will affect the expansion path of roof caving, but make roof caving more sufficient.