Study On Grout Diffusion Mechanism And Direct Plugging Technology For Fractured Rock Mass In Deep Mine

The maximum depth of deep mine shaft in China has exceeded more than 1300 m,and keep downwarding with the speed of 20 m/a.Meanwhile,the construction of deep mine shaft will destroy the aquifer or water system inevitably,resulting the formation of mine water and other disasters,together with the heavy threat to the safety of the mine production.Basing on the construction project of niaoshan mine,the method of theory analysis,numerical simulate,laboratory experiments and site industrial test was adopted.The new plugging technology and slurry diffusion theory of the deep wall of the fractured rock mass is studied.Combined with the fractured rock mass permeability structure types,using geophysical methods to detect the vertical groundwater distribution,to establish the mathematical model of the structure of the physical complex permeability of fractured rock mass,and the flow calculation of rock fracture is carried out.The experiment of direct plugging fiber grouting material was carried out,and the strength,setting time and permeability of different proportioning grouting materials were analyzed.The test bench which can adjust the width of fissure system,water injection system,grouting system and monitoring system is designed,while the simulation of slurry dynamic water diffusion and the real-time monitoring of slurry flow parameters are realized.Combined with the rheological properties of the slurry,the flow equations were established which considering cracks angle,flow velocity,viscosity time-varying slurry,Newton binghamian grouts and power-law slurry.the diffusion rule of the three kinds of grout and the relationship between grouting parameters are studied.Study on the Diffusion Law of Grouting Slurry by Numerical Simulation under Moving Water.The relationship between the maximum diffusion distance of slurry and the relationship between crack angle,diffusion time and grouting pressure was analyzed.The results of theoretical analysis are supplemented and verified.On the basis of the above research,the wind well and the auxiliary well of the niaoshan coal mine were tested in the field of gushing water and achieved good water shutoff effect.The research results will provide scientific basis for deep mine construction,deep coal mining and deep post-wall grouting construction,which has important engineering value and popularization and application prospect.