Theory, technology and application of grouted bolting in soft rock roadways of deep coal mines

The grouted bolt combined rock bolting with grouting techniques, providing an effective solution for controlling the surrounding rock in deep soft rock and fractured roadway. It had been extensively applied in numerous deep mining areas with soft rock roadways and achieved remarkable control results. The development history of grouted bolting theory, design methods, materials, construction processes, parameter monitoring instruments, and effect detection methods was systematically introduced. The overview encompassed several key elements. It delved into anchoring theory and grouting reinforcement theory. The new principle of high pre-mining stress-high-pressure splitting grouted bolting collaborative active control was introduced. A fresh method for dynamic information design was also highlighted. The discussion touched on both conventional grouting rock bolts and cable bolts, as well as the innovative grouted rock bolts and cables characterized by their high pre-tension, strength, and sealing hole pressure. There was an examination of the merits and demerits of standard inorganic and organic grouting materials versus the new inorganic-organic composite materials, including their specific application conditions. The article presented various methods and instruments to assess the support effect of grouting rock bolts, cable bolts, and grouting reinforcement. Furthermore, it provided a foundation for understanding the factors influencing the decision on grouted bolting timing, the sequence of grouting, grouting pressure, the volume of grout used, and the arrangement of grouted rock bolts and cable bolts. The application of the pretensoined high-pressure splitting grouted bolting collaborative control technology in the typical kilometer-deep soft rock mine in China—the soft coal seam and soft rock roadway in the Kizidong coal mine, Huainan coal mining area, was introduced. Finally, the problems existing in grouted bolting control technology for the deep soft rock roadways were analyzed, and the future development trend of grouted bolting control technology was anticipated.