Mechanism And Experimental Study Of Grouting With Flowing Water In Fissure Of Coal—Rock Mass

The prevention and control of underground water hazards is not only of great practical significance to the underground works themselves and to the lives and property of workers,but also to the full development and use of national resources and the protection of the ecological environment.The sustainable development of the national economy is of great significance.As an engineering technology with strong practicality and wide application range,the grouting method is an important method for the prevention and control of water hazards in underground engineering in China.Therefore,systematically studying the diffusion mechanism and plugging mechanism of slurry in fissured coal-rock mass under dynamic action,and applying the theoretical results to practical engineering,is of great value.In this paper,through the theoretical analysis,laboratory tests and numerical simulation methods,the hydrodynamic grouting,sealing mechanism and diffusion mechanism have been deeply studied.The following researches have mainly been carried out:1.Based on the constitutive relation of Bingham fluid,a multi?factor transport mocdel for single fracture hydrodynamic grouting was established.According to the force characteristics of the slurry during the grouting process,the fluid mass conservation equation and the equation of motion are used for theoretical derivation,A hydrodynamic grouting model considering multiple factors is established to analyze the diffusion radius and diffusion profile of the slurry in the slurny-water two-phase flow field.The relationship between the grouting time,grouting pressure,characteristic parameters of grouting material and other factors lay a theoretical foundation for the study of coal-rock fracture creviceowater migration and diffusion behavior.2.Development and Application of Multifunctional Dynamic WateA Injection Grouting Simulation Test Platform,Independently designed and developed a comprehensive test platform,which includes fracture simulation system,dynamic water source system,grouting system,flow velocity,grouting pressure data acquisition system,simulation rough surface device,test frame system,and slurry flow visualization device.The grouting effect and the diffusion mechanism of the slurry under different test conditions such as grouting pressure,water flow velocity,grouting material,crack opening,etc.were studied and recorded through the combination of experimental platform and theoretical research phase results.3.Experimental study on different grouting factors and grouting effect.Through experimental means,the impact of cement slurry on the grouting effect under different water-cement ratios and different grouting pressures was analyzed.The diffusion laws of pure cement slurry(different water-cement ratios)under different experimental conditions in simulated fractures were observed.Experiments were carried out under the conditions of opening degree,and the grouting effect and the law of slurry diffusion were compared in each case;the phenomenon of water layer separation in the cement slurry was investigated;and the technological method of reducing the flow rate of moving water by the aggregate was studied and analyzed.4.Combining the results of theoretical derivation and laboratory tests,FLUENT fluid mechanics software was used to simulate and analyze the diffusion patterns and laws of cement slurry and different grouting in the slurry-water two-phase fluid field using the VOF model in the software multiphase flow model.The details of the flow field under the conditions,etc.,and the simulation results are compared with the experimental results and theoretical analysis.