Study On Mechanism Of Split-infiltration And Pressure Relief-induced Grouting In Deep Buried Broken Rock Mass

In the process of roadway excavation and face mining,the heavy distribution of stress and the dynamic pressure of coal mining will aggravate the coal and coal under the influence of high ground stress and geological activity.Rock deformation and damage are affecting the stability of the roadway and the safe face of the mining.Grouting reinforcement is a commonly used reinforcement technology in geotechnical engineering,which can effectively improve the physical and mechanical parameters of the reinforcement object and improve the self-bearing capacity of rock and soil.In this paper,based on the background of Zhaozhuang Coal Industry,this paper analyzes the grouting material performance of coal and rock mass by means of experimental study,theoretical analysis,numerical simulation and field engineering test.Reinforcement effect,grouting parameters influencing factors,the mechanism of interaction between seepage and splitting grouting,and so on.The main results are as follows:(1)The relationship between the grouting pressure and the diffusion range in the grouting grouting was obtained by analyzing the diffusion of the slurry along the plane fissure and the one-way diffusion along the plane fissure.Based on the elastic mechanics theory,the grouting pressure value of the grouting hole wall under the action of slurry pressure and geostress is calculated.It is found that the maximum factor affecting the pressure required for splitting grouting is the same as the grouting hole the larger the ratio of ?1 and ?3 in the vertical plane,the easier it is to realize the splitting of the grouting hole wall.The pressure value and the extended length of the fracture are calculated and calculated based on the damage fracture mechanics theory.(2)In order to grouting the broken coal,a grouting device was designed on the basis of the relevant information.The peak strength and confining pressure,peak intensity and porosity,peak intensity and grouting pressure,residual strength and confining pressure,residual strength and porosity were obtained.Rate,residual strength and grouting pressure,peak strain and confining pressure,peak strain and porosity,peak strain and grouting pressure were analyzed and discussed.The influence of porosity and grouting pressure on grouting effect was obtained?The peak strength of grouting increases with the increase of the strength of material being grouted and grouting material,but the peak intensity of grouting solid is mainly determined by the strength of the grouting material(3)Two-dimensional and three-dimensional models were established by software COMSOL,and the grouting simulation was carried out by different grouting,different grouting pressure and different grouting materials.The influence of porosity,grouting pressure and slurry viscosity on the grouting effect was analyzed according to the change of pore water pressure in the selected point.(4)Based on the engineering geological conditions and the mining condition of the working face,the technical scheme and parameters of the deep hole tunnel grouting reinforcement in the fully mechanized coal mining face are put forward.According to the scheme,the working surface is grouted and tracked at the later stage.The results show that the grouting effect of the design has reached the expected target,and the stability of the working face has been improved by the analysis of the coal wall,the roof drop,the deformation of the roadway,the use of the mine and the speed of the working face play very important role.