Current status and progress of subsidence control technology in China coal mines

The large-scale and high-intensity mining of coal has led to increased mining-related damage, including surface subsidence, ecological degradation, and damage to buildings, railways, and high-voltage transmission lines. These issues have intensified the conflict between resource extraction and environmental protection, making low-loss coal mining an essential requirement for sustainable development. This paper provides a comprehensive analysis of coal mining subsidence control technologies in China, including backfill mining, coordinated mining, partial mining, and grouting bed separation. The implementation principles and application methods of these subsidence control technologies are discussed in detail, along with an analysis of their advantages and disadvantages, existing challenges, applicable conditions, and research advancements. Based on practical engineering applications, the paper examines the effectiveness of surface subsidence control using grouting bed separation, backfill mining, and coordinated mining technologies, highlighting their limitations and future development trends. The results show that grouting bed separation technology offers the advantages of minimal interference with underground mining operations, facilitates green mining practices, and supports the utilization of solid waste. Additionally, further research in China is needed in the following areas: the development of cost-effective, high-performance backfilling materials and process optimization; investigation of the surface deformation mechanisms during coal seam mining to improve subsidence prediction theories; development of efficient coal pillar recovery methods and enhancement of long-term pillar stability; and optimization of the grouting process for bed separation technology, while evaluating the impact of slurry on the groundwater environment.