Study On Grouting Simulation Test And Grouting Technology Optimization In Old Mining Crushing Zone

Based on the survey of the old mining roadway in the mine,the paper has analyst the slurry in the crushed coal and rock mass diffusion process and put forward the secondary mining face pre-grouting process.The main work of this paper is:1、Based on the known mine data,the excavation condition of roadway excavation and the mining area of working face is used to analyze the situation of the roadway in the old mining area of 1301 secondary mining face of Shenghua Coal Mine.According to the surface of the roadway and the roadway excavation in the roadway to reveal the characteristics of the roadway layout map.2、The design of scattered coal and rock accumulation of the grouting test,the model of slurry diffusion analysis is put forward by experiment and has given the theoretical analysis of this model.Using MATLAB analysis software,the slurry diffusion law under the influence of different grouting pressure,water-cement ratio and permeability coefficient parameters was analyzed by linear regression analysis.Obtained the linear relationship between the three factor of the slurry water-cement ratio,grouting pressure,permeability coefficient and the maximum diffusion length of the slurry,the maximum injection length,grouting and stone compressive strength,four sets of linear regression equations were obtained:（?）and P =6.607·-S^-0.6920 ·w^0.215 ·p^-0.0439.3.Through the establishment of FLUENT fluid analysis model,the grouting model of grouting coal blasting is improved,the maximum diffusion length of the slurry and the maximum injection length can be deduced.,the experimental data are optimized and the corresponding linear regression relation is obtained:L= 105.6466·S^-0.2631·k^5.8885·p^0.5776 and R=183.2772 · S^-0.1952·k^8.1937 · p^0.5537.4、According to the linear regression relationship of slurry diffusion,multi-step progressive grouting technology is designed.First of all,the boundary of the complexed crushing zone is groded to realize a dense plugging zone with a thickness of 3m,with the slurry water-cement ratio of 5:1,the grouting pressure of 1MPa,the height from floor of 1.6m,inclination of 17°,the length of 1.36m,and the drilling spacing of 2.5m.Then,slurry reinforcement area slurry water-cement ratio of 7:1,grouting pressure of 9.5MPa,in accordance with the ultra-high water material slurry diffusion characteristics of the design of three rounds of progressive grouting,each interval 13.3m,from the bottom plate 1.5m drilling grouting Hole,inclination angle of 26°、10°、6°,respectively,the hole length of 9.1m,21.9m,35m,single-shot grouting drilling distance of 10m,each adjacent two round grouting hole spacing of 3.3m.5.The grouting effect was detected by COMSOL numerical simulation and grouting in the compound area.The reasonableness of the multi-round grouting process was verified,and the coal wall after grouting was smoothed and the integrity was more well,the grouting effect is good.