| With the increasing mining depth of the Jinchuan No.2 mining area,the deformation and destruction phenomenon of the roadway becomes more and more obvious,and even presents a non-benign circulation situation of “destruction-rework-re-destruction”.It can be seen that the current research results and support methods for the middle and shallow roads are no longer applicable to deep mine projects.In order to guide the development of high-efficiency and lowcost mining technology in the deep mine and deep mining engineering design,and to serve the mine safety production,it is necessary to carry out the following research: provide the basic ground stress data urgently needed in the deep engineering of the mine,analyze the deep geostress state,and Comprehensively explore and master the current stress distribution law of the mine.Based on the project “Research on the safety,high-efficiency and low-cost mining technology in deep and lean mines of Jinchuan Mine — Deep Geostress Test Research”,this paper has carried out the following work:(1)Systematic analysis and analysis of previous raw rock stress measurement work and rock mechanics research results As far as possible,this study will make up for the gaps and deficiencies of previous work;(2)investigate the engineering geological situation of the mining area,define the geological conditions,understand the basic characteristics of each engineering geological rock group,and select the faults that have a greater impact on the mining area.The research object;(3)The ground stress measurement work is carried out by the hollow inclusion stress relief method and the hydraulic fracturing method to make up for the shortage of the ground stress data in the middle section of the 1000m-850 m deep section of the second mining area,and the blank of the ground stress data of the middle section of 850m-700 m.Analyze the current deep stress state and action characteristics;(4)Combine the research results of the middle and shallow parts with the comparative analysis of the deep ground stress characteristics,and understand the law of mine stress change;(5)Use the ANSYS finite element simulation software to select new rock mechanics Parameters,inversion of the stress distribution state of the three middle sections of the mining area of 1000 m,850m and 700 m,comprehensive Master the status of geostress in various types of rocks,faults,and junctions in the middle section to guide the next step in the mining area.The results of this study show that:(1)In the deep part of Jinchuan No.2 Mine,the maximum principal stress direction in the deep part of the mining area is still NNE-NE direction;(2)With the increase of depth,the growth rate of the maximum principal stress is much larger than the maximum horizontal principal stress increase.At the speed,the maximum principal stress inclination angle is obviously larger than that of the middle and shallow parts,mostly at 25°,and up to 48°,and the horizontal stress gradually loses its leading role.Instead,it is vertical stress,and the level of 1000m-700 m is on this transition zone.In this paper,the fitting formulas of various stresses with depth are given.(3)Combined with the simulation results,the stress distribution in all kinds of rocks is uniform,but the shear stress increases obviously,which has become one of the important factors affecting the stability of the mining area.(4)The impact of the Fc fault on the mining area is limited,and the effect of the F16 fault is more significant,and its effect becomes more and more obvious with the increase of the mining depth;(5)The analysis of the stress state of each measuring point indicates that the roadway needs new The support program,and this study provides theoretical basis and technical support for the subsequent redesign of the roadway. |
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