| The problem of sudden gushing water in surrounding rock fissures affects the construction of underground engineering and has the characteristics of high suddenness,great harm and huge economic losses.Therefore,it is of great importance to study the grouting plugging theory and technology of sudden gushing water.In this paper,a visualized grouting model device for plane fractures is developed,and the slurry diffusion law under different parameters is studied.Fluent software is used to carry out grouting simulation calculation for three-dimensional plane fractures.Through the combination of indoor model test and numerical simulation,the migration and diffusion law of slurry in plane fractures is studied,and the influences of various factors on slurry diffusion law,measuring point pressure,plugging effect and other parameters are analyzed.The main research contents and results are as follows:(1)The reaction mechanism of cement-water glass slurry is introduced.According to the time-varying characteristics of cement-water glass slurry,the diffusion distance of laboratory test slurry is compared with the simulated diffusion distance of Fluent software,and the viscosity change function of slurry is determined.(2)A visual plane fracture grouting model system is established,mainly including a simulated fracture test bed system,a fracture water supply and drainage system,a test grouting system and a test data monitoring and acquisition system,which can realize the grouting diffusion law research under different working conditions,and real-time monitoring and recording of various parameters are carried out by using pore water pressure meter,electromagnetic flowmeter,camera and other equipment.(3)Through the indoor model test,it is analyzed that the slurry diffuses circularly under the condition of still water,and the pressure gradually decreases from the grouting hole along the direction of slurry diffusion;Under dynamic water conditions,the slurry initially diffuses circularly.With the increase of grouting time,the diffusion rate of slurry along the direction of water flow is faster,and the diffusion form changes to U-shape.Under single parameter variables such as dynamic water velocity,dynamic water pressure,fracture opening,and different slurry ratio,the grouting diffusion law of slurry under dynamic water conditions and the water plugging effect are analyzed.(4)The computational fluid dynamics software Fluent is used to carry out the numerical simulation of plane fissure grouting for the three-dimensional model system,and the variation laws of slurry diffusion radius,line pressure and lateral line velocity with time are studied.The comparison with the slurry diffusion laws of indoor model tests proves the reliability of the results.The non-simulation conditions of indoor model tests are studied by Fluent software. |
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