In the heart of China’s coal mining industry, a groundbreaking study is set to revolutionize water control in inclined shafts, particularly in dynamic water sandy areas. Led by FAN Gangwei from the School of Mines at China University of Mining and Technology, the research delves into the intricate world of curtain grouting, a critical process for managing water influx in mining operations.
The study, published in the esteemed journal ‘Yantu gongcheng xuebao’ (translated to ‘Geotechnical Engineering’), focuses on the Caojiatan coal mine’s sandy area sloping shaft curtain grouting. The research team, including REN Chuangnan and ZHANG Dongsheng, established a slurry diffusion model that considers the time-varying slurry viscosity and long-term coupling of percolation effect. This model is a significant leap forward in understanding the behavior of slurry in dynamic water sand layers.
“Under the condition of grouting in the dynamic water sand layer, the spreading pattern of the slurry in the horizontal direction is ‘ellipsoid-like’, and in the vertical direction is ‘tornado-shaped’,” explains FAN Gangwei. This discovery is crucial for optimizing the grouting process and ensuring effective water control.
The study found that increasing the grouting pressure can counteract the scouring effect of moving water to a certain extent. However, when the grouting pressure is increased to 0.5 MPa, the increase in the spreading distance of the slurry decreases due to the influence of the grouting characteristics of the sand layer. This finding highlights the importance of balancing grouting pressure to achieve optimal results.
One of the most significant findings of the study is the determination of the curtain grouting holes and row spacing of 2.0 m and the minimum safe curtain thickness of 6.0 m for the sloping shaft in the dynamic water sanding area. This information is invaluable for the energy sector, as it provides a clear guideline for implementing effective water control measures in similar geological conditions.
The field industrial test results were impressive, with the core rate of the treatment area exceeding 80%, water influx attenuation at 85.6%, and a high slurry consolidation degree. These results underscore the practical applicability of the research findings and their potential to enhance the efficiency and safety of mining operations.
The research conducted by FAN Gangwei and his team is set to shape future developments in the field of water control in mining operations. By providing a theoretical basis and practical reference for similar projects, this study paves the way for more efficient and safe mining practices in dynamic water sandy areas. As the energy sector continues to evolve, such advancements are crucial for meeting the growing demand for energy while ensuring the sustainability and safety of mining operations.