Influence Characteristics And Mechanism Of Fragmental Size Of Broken Coal Mass On The Injection Regularity Of Silica Sol Grouting

Fragmental size of broken rock mass has a significant effect on silica sol grouting regularity. Firstly, the relationship between porosity, permeability and variable fragmental size of Case 1 (<2 mm), Case 2 (2-5 mm), Case 3 (5-10 mm), Case 4 (continuous mixed sizes) and Case 5 (intermittent mixed sizes) was analyzed. Then, the influence characteristics and mechanisms of fragmental size on the injection regularity of silica sol grouting regularity were studied based on a developed grouting permeation monitoring device, the critical Reynolds number for flow regime transformation and colloid filtration theory. The results mainly showed that (1) The injection regularity of silica sol grouting in broken coal mass generally presented a three-stage regularity. The fragmental size had a great impact on the 2nd and 3rd stage. (2) A colloidal film was formed into the inlet surface of coal sample based on the two mechanisms of deposition and straining. (C) 2020 Elsevier Ltd. All rights reserved.