Spatial structure of overlying rock strata and advanced abutment stress evolution in deep filling mining: A case study

Abstract

Abstract Filling mining is one of feasible methods to prevent rock burst in coal mining, which is a meaningful topic in the field. In this paper, we first described the filling mining effect based on 'equivalent mining height' and analyzed the evolution of overlying rock strata. It was found that time-space hysteresis occurred during the movement of overlying rock strata in filled working face. (Movement of overlying rock strata took a period of time to reach the location of traditional caving) On this basis, mechanical relationship of dynamic transformation among 'filling rate-strata movement-abutment stress' was obtained by analyzing the coal stress characteristics. Then, advanced abutment stress estimation model of filled working face in deep coal mine was established. Finally, the C5301 working face of Yunhe coal mine was taken as the engineering background, example calculation and field monitoring were carried out. The results showed that the influence range of the advanced abutment stress is 91 ~ 97 m, and the peak value is 41.1 MPa, which is 21 ~ 50 m away from the working face. In addition, large pressure step and long interval time were the characteristics of time-space hysteresis in the filled working face. This study could provide guidance and reference for overlying rock strata and advanced abutment stress evolution in deep filling mining under the same or similar conditions.