Study on slurry diffusion law in goaf under different grouting pressure
Cheng Lichao1,2,3, Lu Bin1, Li Xinwang1,2,3, Hao Yunde1, Long Hang1, Wang Haixuan1
1. School of Mining Geomatics Engineering, Hebei University of Engineering, Handan 056038, China;
2. Coal Resources Development and Construction Application Technology Research Center of Universities in Hebei Province, Hebei University of Engineering, Handan 056038, China; 3. Handan Coal-based Solid Waste Scale Utilization Technology Innovation Center, Hebei University of Engineering, Handan 056038, China
Abstract: In order to study the law of slurry migration and diffusion in the complex space of goaf, the cement fly ash slurry was taken as the research object. By analyzing the rheological properties and flow characteristics of the slurry, the time-varying equation of viscosity was determined. The finite element numerical simulation method was used to establish the grouting diffusion model of cement fly ash slurry in goaf, and the diffusion range of grouting slurry at different times was obtained. The relationship between grouting diffusion radius and grouting pressure was studied. The results showed that the cement fly ash slurry belongs to the Bingham fluid. In the grouting process, its viscosity gradually increased with time, and the slurry flow velocity decreased. The diffusion form of cement fly ash slurry in the gangue pile in the goaf initially changed from sphere to cylinder. The diffusion radius of slurry increased with the increase of grouting time, and the change rate decreased with the increase of slurry viscosity. The diffusion radius of slurry reached 10.49 m at 10 h. The change of grouting pressure had a strong influence on the slurry diffusion speed. When the grouting pressure was 0.2MPa, the slurry diffusion distance was 10.01 m.When the grouting pressure was 0.5MPa, the slurry diffusion distance was 14.51 m.Whenthe grouting pressure was 1MPa, the slurry diffusion distance was 18.96m. It was concluded that the smaller pressure could be provided in the early stage of grouting, and the grouting pressure could be appropriately increased to improve the grouting efficiency. This study provided a theoretical basis for improving and optimizing the grouting process in goaf.
程立朝1,2,3,路 滨1,李新旺1,2,3,郝云德1,龙 杭1,王海璇1. 不同注浆压力下采空区浆液扩散规律研究[J]. 煤炭与化工, 2023, 46(9): 1-6.
Cheng Lichao1,2,3, Lu Bin1, Li Xinwang1,2,3, Hao Yunde1, Long Hang1, Wang Haixuan1. Study on slurry diffusion law in goaf under different grouting pressure. CCI, 2023, 46(9): 1-6.