Forty years development and prospects of underground coal mining and strata control technologies in China

Mining methods, equipment and strata control technologies are the core elements to ensure the normal production of coal mining.This paper introduces the development process of coal mining methods and equipment, strata control theories and associated technologies, special coal mining and mining ecological environmental protection technology during the 40 years of reform and opening-up in China since 1978.Based on the scientific and technical research projects initiated and participated by the Mining Research Branch of the China Coal Research Institute, the main achievements obtained from coal mining and strata control technologies in the past 40 years were summarized in the following aspects: the fully mechanized mining technology and equipment for thin, medium thick, and thick coal seams, the fully mechanized top coal caving mining technology and equipment for thick and extra-thick coal seam, and the technology and equipment for intelligent mining; the movement and breaking laws of strata overlaid above working faces, the mechanical hypothesis of strata structures, the interaction between shields and surrounding rock, and the control technologies for hard and broken roofs; roadway rock bolting theories and complete set of technologies, grouting reinforcement technology for fractured rock, and the destressing technology with hydraulic fracturing for roadways with high stresses or affected by serious mining activities; rock burst occurrence mechanism, assessment methods for burst risk zones, and the rock burst monitoring with early-warning and integrated control techniques; mining subsidence theories, special mining methods such as mining under buildings, water body, and mining above confined aquifer, as well as the ecosystem and environmental protection in mining areas.The 40-year researches and practices show that a complete set of technical systems for coal mining and strata control have been formed in China with special Chinese characteristics, which provides reliable technical supports for safe, efficient and green production of coal mines.Besides, the future development and suggestions for coal mining and strata control technologies are provided. © 2019, Editorial Office of Journal of Mining and Strata Control Engineering. All right reserved.