Study On Stability Of Isolated Pillars In Xiabao Mining Area

Based on the high-efficiency and safe mining of the upper 120 m isolation pillar of Yinhai Mining in Jiangxi Province,combined with on-site engineering geological survey and indoor rock mechanics test results,the research methods of catastrophe theory,strength reduction method and numerical simulation are used to analyze the goaf under the filling body.Roof stability,and 120 m isolation pillar safe mining optimization program.The main results are as follows:(1)Through the engineering and hydrogeological investigation and the test of mineral rock mechanics parameters,the RMR and BQ methods are used to evaluate the engineering quality of the rock mass in the mining area,and the Yinhai mining ore body is a Grade I rock mass,indicating that the quality is very good,span 15 m.It is stable for 20 years;granite porphyry and crystal tuff are II-grade rock mass,indicating good quality and stable and stable for 1 year within 10 m span.(2)Combining GSI evaluation method,elastic wave method,coefficient conversion algorithm and indoor rock physics and mechanics test,numerical simulation of rock mass mechanical parameters is recommended.(3)Establish a three-dimensional numerical model of Yinhai Mining,set up surface monitoring points,study the influence of the upper 120 m isolated pillar excavation and filling on the stability of the ground,and the maximum surface inclination(i)and maximum surface curvature of the eight surface points(K)and maximum horizontal deformation(?)know that the isolation and filling of the isolated rock mass will not adversely affect the stability of the surface buildings.(4)Based on the catastrophe theory and strength reduction method,the cusp catastrophe model is established,and the safety factor of the roof in the goaf under the filling body is calculated.The roof safety factor of different roof thickness and height of different goafs under the pressure of the filling body is analyzed.The situation,and the relationship between the safety factor of the roof and the ratio of the thickness of the roof and the height of the goaf,it is concluded that the safety factor of the roof under the filling body increases with the thickness of the roof plate,and decreases with the height of the goaf.Increases as the ratio increases.(5)Combining the research on the stability of goaf based on cusp catastrophe theory and strength reduction method,the advantages and disadvantages of different mining schemes for isolated pillars are analyzed.