Study On Kinetic Mechanism And Influence Factors Of Grout Migration In Fractured Rock Mass

Shallow coal resources are increasingly exhausted in China. For the mining of deep coal resources, a higher demand has been put on the mine water control technology because of complicated hydrogeological conditions. As one of main means of controlling mine water, grouting technology has been developed by leaps and bounds after decades of research. However, due to draggling of theoretical research, grouting effect is very difficult to be guaranteed. Therefore, studying on grouting theory is very important to scientifically guide parameter determination and engineering design in grouting, and is of great significance to improving grouting project quality.Based on the study of kinetic mechanism that grout migrates in fractured rock mass, the diffusion equation of Bingham grout in saturated fractured rock mass is obtained, the model solution and parameter setting of the equation are discussed. It is found that the kickoff pressure gradient is the key parameter influencing grout diffusion in Bingham grout, through theoretical studying on the effects of grouting hole radius, porosity percentage, grout viscosity, permeability coefficient and kickoff pressure gradient. In addition, the paper demonstrates that the pressure loss caused by overcoming the starting shear forceÏ„₀ is the major factor by analysis of the factors and characteristics about grout pressure loss along the flow way, the flow mechanism of Bingham grout in saturated rock mass is also revealed. Finally, research results were applied to Dongshan Coal Mine collapse column grouting engineering to optimize grouting parameter design, good result was achieved, which means the paper conclusions are of practical value.