Analysis Of The Impact Of Mining In The Middle Section Of A Mine On The Lower Wall Transportation Tunne

With the deepening of mining depth of metal mines,the depth of roadway construction is deepening.Only by correctly understanding the influence of ore body mining and goaf treatment on roadway can we better guide roadway support design.In this paper,the actual situation of the transportation roadway in the 1430 m middle section of the self-propelled iron mine is affected by mining and the stress peak arrives in advance as the research object.Combined with the indoor rock physical and mechanical test,field monitoring and investigation,theoretical analysis based on the cusp catastrophe theory and FLAC 3D numerical simulation test,the influence of mining the ore body in the 1477 m layer to the 1430 m layer and controlling the goaf of each layer on the transportation roadway in the 1430 m middle section is studied.The main work and results are as follows :(1)The rock physical and mechanical parameters of the mine were obtained by field sampling and indoor rock mechanics test.Through the field investigation of the transportation roadway and the stope,including the field structural plane investigation,the physical and mechanical parameters of the rock mass of the mine were obtained by the rock mass strength reduction method according to the field investigation results.(2)According to the actual situation of the transportation roadway in the middle section of 1430 m,combined with the failure mode of the roadway and the actual situation of the roadway support,the cusp catastrophe analysis model of the surrounding rock stability of the transportation roadway is established.According to the actual situation of the roadway and the ground pressure monitoring data,the accuracy of the model is verified.Using this model combined with the actual situation of the roadway,the more volatile areas in the ground pressure monitoring data were corrected.Combined with the revised ground pressure monitoring data,it is finally speculated that there may be an approximate butterfly-shaped influence area around the goaf after mining the 1477 m layered to 1430 m layered partial ore body,and the influence area moves down synchronously with the downward movement of the goaf.(3)After mining the ore body in each layer of the steeply inclined ore body and controlling the goaf in each layer,the stress of the transportation roadway in the 1430 m middle section is mining from top to bottom with the ore body under the influence of mining.After mining the 1462 m layered ore body,the stress of the roadway reaches the maximum,and the stress of the roadway decreases with the continuous downward mining of the ore body.The change law of displacement in the area where the roadway is located is the same as that of stress.That is,after mining the 1462 m layered ore body,the deformation of the area where the roadway is located reaches the maximum.As the ore body continues to be mined downward,the displacement of the roadway continues to decrease.(4)After mining each layer of the vertical ore body and controlling the goaf of each layer,under the influence of mining,the stress of the transportation roadway in the 1430 m middle section shows that the stress and displacement of the roadway area are increasing with the mining of the ore body from top to bottom.