Self-imbibition grouting and argillaceous rock mass anti-seepage reinforcement with silica sol
The mud of argillaceous soft rock is an important crux of long-term large deformation and instability of coal mine argillaceous rock mass roadways.Aiming at the poor injectability of cement slurry to micro-cracks in the rock mass during the mudstone grouting reinforcement process,which leads to poor anti-seepage and reinforcement effect,the feasibility of a new type of nano-silica sol grouting for the anti-seepage reinforcement of argillaceous rock mass was systematically studied.Based on the micelle structure of silica sol,the gel principle of silica sol is clarified,and the particle size grade of grouting silica sol is optimized.The basic physical and mechanical properties of silica sol and the basic anti-seepage characteristics of consolidated argillaceous soft rock are analyzed.The results show that silica sol has significant advantages over conventional grouting materials in terms of grout injectability,gel volume stability,and anti-seepage of the grouting structure.But the gel strength is less.The pore volume and permeability of argillaceous rock mass can be significantly reduced by silica sol grouting bonding,and the permeability coefficient can be reduced to 10-9 cm/s,which can meet the anti-seepage project of grouting argillaceous micro-cracked rock mass in coal mine roadways need.Aiming at the inefficiency of conventional silica sol grouting method for argillaceous rock mass matrix system grouting,based on the affinity between mudstone micro-cracks and silica sol,the grouting method of silica sol self-absorption infiltration grouting method for argillaceous rock mass was studied.The imbibition grouting of 0.1-40 mD low-permeability muddy core was realized,and the mechanism of imbibition grouting of silica sol was revealed from the microscopic scale.The results show that the grouting permeability of silica sol to low-permeability mudstone can be further improved by using the imbibition property.Aiming at the insufficient strength of silica sol-gel,a cross-scale composite modified slurry with silica sol as the main component and high injection height reinforcement was preliminarily developed by using aluminate cement as the modified reinforcing agent.The slurry material has outstanding performance in injectability,rheology,gel controllability,and stone body strength and volume stability,and can achieve dual functions of sealing and strengthening argillaceous rock mass.
rock mechanicsargillaceous low-permeability rock masssilica solgrouting anti-seepageinjectabilityimbibition groutingsilica sol modification and enhancement