Numerical Simulation of Diffusion Regularity and Parameter Optimization of Shaft Grouting Slurry

Abstract

Increase in downhole mining prompts the need to develop effective methods for maintenance of shafts. Currently, grouting behind the shaft wall is the main approach used for prevention of water seepage into the shaft. Several factors determine the grouting effect, and grouting often fails during field applications due to use of ineffective parameters. In the present study, numerical simulation was performed to evaluate slurry diffusion regularity under different grouting parameters based on the factors that affect shaft grouting. The simulation results showed that the overall diffusion radius of the slurry increased with increase in grouting time and stabilized toward the end of the simulation, under different grouting parameters. Porosity of the surrounding rock near the grouting hole gradually became denser with an increase in time, which is not conducive for diffusion of the slurry. The amount of water gushing at 146 m below the secondary shaft of Zhundong No. 2 mine decreased by 81% after optimizing the grouting parameters for application at the actual site. This decrease in amount of water had a significant anti-seepage effect, and it reduced grouting costs. The findings of the present study provide a basis for conducting subsequent shaft grouting projects.

Grouting anchor cable active advanced support technology for mining roadways

“…When the pressure increases to a certain value, the effect of increasing the slurry diffusion radius is weakened, and excessive grouting pressure may cause further damage to the roof surrounding rock, which is not conducive to tunnel maintenance 35 . Prolonging the grouting time will gradually increase the diffusion radius of the formation in the formation, but it will not increase the diffusion radius of the grout to a large extent 36 , 37 .…”

Development of Grouting Test System for Rough Fissure Rock Body and Research on Slurry Diffusion Law

“…Guo et al [27] concluded that the fracture boundary effect has a non-negligible influence on the slurry diffusion, and obtained the streamline equation for the slurry diffusion trajectory. Pan et al [28] analyzed the influence of grouting volume, grouting pressure, and other factors on the grout diffusion pattern, concluding that, under different grouting parameters, the grout diffusion radius is directly proportional to the grouting time. Liu et al [29] developed a novel dynamic grouting test system to study the impact of water flow rate, grout flow rate, and fracture aperture on grout diffusion characteristics, concluding that increasing the grout flow rate and fracture aperture can effectively control fracture formation.…”