Study On Dynamic Evolution Of Ground Pressure And Stability Of Zhongguan Iron Mine

Zhongguan Iron Mine is one of the key mines in Hebei Province.In October 2020,the first chamber was mined.In order to ensure the high yield,high efficiency and safe production of the first mining activities and the subsequent large-scale production.Therefore,take mining field as the research object,complex utilization of field experiments,numerical simulation and theoretical calculation,summarize the evolution law of ground pressure and determine the stability of mining,combined with the cusp catastrophe theory,calculate the stability of the pillar-roof system,put forward reasonable suggestions for the optimization of the chamber parameter.The main research results are as follows:1)Through the indoor point load experiment,the joint crack investigation,field in situ stress measurement and ground stress inversion based on numerical simulation,determine the engineering rock mass grade,and the stope area rock stress distribution rules,provide rock parameter setting basis and boundary loading conditions.2)The mining situation of the first mining chamber of Zhongguan Iron Mine is stable,and the numerical simulation situation is consistent with the stress change measured in the field.When the chamber is gradually mined,the horizontal and vertical stress on both sides is decreases,and the shear stress increases.The shear stress in the XY direction and XZ direction mainly affects the stability of the roof of the approach,and the shear stress in the YZ direction mainly affects the stability of the ore column;The vertical stress of the upper rock chamber changes slightly with mining.3)The mining of phase mining of Zhongguan Iron Mine is stable,when the first step mining,the stress is distributed again,the pressure is borne by the mine column,the second step mining,the vertical stress shifts to the upper and lower plate and the surrounding ore rock,the pressure of the filling is not high,it is mainly the limiting displacement.4)According to the analysis of cusp catastrophe model,the stability of the pillarroof system is influenced by internal and external factors,internal factors is the structure parameters of pillar and roof,external factors is the roof uniform load;Among the key factors selected,the influence on the stability is from large to small: span,roof thickness,ore column area,ore column height;According to the formula,the pillar-roof system formed by Zhongguan Iron Mining is stable,when mined under the filling body,the roof thickness shall not be less than 9m.Figure 60;Table 18;Reference 62...